The Critique of Pure Reason.............................................................................................................................1

Immanuel Kant .........................................................................................................................................1

PREFACE TO THE FIRST EDITION, 1781 .........................................................................................2

PREFACE TO THE SECOND EDITION, 1787 ....................................................................................6

INTRODUCTION................................................................................................................................15

I. Of the difference between Pure and Empirical Knowledge...............................................................15

II. The Human Intellect, even in an Unphilosophical State, is in Possession of Certain

Cognitions "a priori". .............................................................................................................................16

III. Philosophy stands in need of a Science which shall Determine the Possibility, Principles, and

Extent of Human Knowledge "a priori" ................................................................................................17

IV. Of the Difference Between Analytical and Synthetical Judgements. ..............................................18

V. In all Theoretical Sciences of Reason, Synthetical Judgements "a priori" are contained as

Principles...............................................................................................................................................19

VI. The Universal Problem of Pure Reason. ..........................................................................................21

VII. Idea and Division of a Particular Science, under the Name of a Critique of Pure Reason...........23

SS I. Introductory. .................................................................................................................................24

SECTION I. Of Space. ..........................................................................................................................25

SS 2. Metaphysical Exposition of this Conception. ..............................................................................25

SS 3. Transcendental Exposition of the Conception of Space. ..............................................................26

SS 4. Conclusions from the foregoing Conceptions.............................................................................27

SECTION II. Of Time..........................................................................................................................28

SS 5 Metaphysical Exposition of this Conception. ................................................................................28

SS 6 Transcendental Exposition of the Conception of Time. ................................................................29

SS 7 Conclusions from the above Conceptions....................................................................................29

SS 8 Elucidation. ...................................................................................................................................30

SS 9 General Remarks on Transcendental Aesthetic. ...........................................................................32

SS 10 Conclusion of the Transcendental Aesthetic...............................................................................36

Transcendental Logic. FIRST DIVISION. TRANSCENDENTAL ANALYTIC. SS I. ......................40

BOOK I. ................................................................................................................................................41

SS 2 Analytic of Conceptions. .............................................................................................................41

CHAPTER I. Of the Transcendental Clue to the Discovery of all Pure Conceptions of the

Understanding. .......................................................................................................................................41

SS 3. Introductory. ................................................................................................................................41

SECTION I. Of defined above Use of understanding in General. ........................................................41

SS 4........................................................................................................................................................41

SECTION II. Of the Logical Function of the Understanding in Judgements. ......................................42

SS 5. ......................................................................................................................................................42

SECTION III. Of the Pure Conceptions of the Understanding, or Categories. .....................................44

SS 6.......................................................................................................................................................44

SS 7.......................................................................................................................................................47

SS 8.......................................................................................................................................................48

CHAPTER II Of the Deduction of the Pure Conceptions of the Understanding. .................................49

SECTION I Of the Principles of a Transcendental Deduction in general. ..........................................49

SS 9........................................................................................................................................................49

Transition to the Transcendental Deduction of the Categories. SS 10.................................................51

SECTION II Transcendental Deduction of the pure Conceptions of the Understanding. ....................53

SS 11 Of the Possibility of a Conjunction of the manifold representations given by Sense.................53

Of the Originally Synthetical Unity of Apperception. SS 12...............................................................53

The Principle of the Synthetical Unity of Apperception is the highest Principle of all exercise of

the Understanding. SS 13 .......................................................................................................................55

What Objective Unity of Selfconsciousness is. SS 14.......................................................................56

The Logical Form of all Judgements consists in the Objective Unity of Apperception of the

Conceptions contained therein. SS 15..................................................................................................56

All Sensuous Intuitions are subject to the Categories, as Conditions under which alone the

manifold Content of them can be united in one Consciousness. SS 16 ................................................57

Observation. SS 17...............................................................................................................................57

In Cognition, its Application to Objects of Experience is the only legitimate use of the

Category. SS 18.....................................................................................................................................58

SS 19.....................................................................................................................................................58

Of the Application of the Categories to Objects of the Senses in general. SS 20...............................59

SS 21.....................................................................................................................................................61

Result of this Deduction of the Conceptions of the Understanding. SS 23.........................................63

BOOK II. Analytic of Principles..........................................................................................................65

CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding...........................66

CHAPTER II. System of all Principles of the Pure Understanding.....................................................70

SECTION I. Of the Supreme Principle of all Analytical Judgements. ..................................................71

SECTION II. Of the Supreme Principle of all Synthetical Judgements. ...............................................72

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. ...73

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena...........103

I. Of Transcendental Illusory Appearance. .........................................................................................118

BOOK I. OF THE CONCEPTIONS OF PURE REASON.................................................................123

SECTION I Of Ideas in General. .....................................................................................................124

SECTION II. Of Transcendental Ideas. ..............................................................................................126

SECTION III. System of Transcendental Ideas. .................................................................................130

BOOK II. OF THE DIALECTICAL PROCEDURE OF PURE REASON........................................132

CHAPTER I. Of the Paralogisms of Pure Reason. .............................................................................132

CHAPTER II. The Antinomy of Pure Reason. ...................................................................................142

SECTION I. System of Cosmological Ideas. ......................................................................................143

SECTION II. Antithetic of Pure Reason. ............................................................................................147

SECTION III. Of the Interest of Reason in these Selfcontradictions. ..............................................159

SECTION IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its

Transcendental Problems. ....................................................................................................................163

SECTION V. Sceptical Exposition of the Cosmological Problems presented in the four

Transcendental Ideas. ...........................................................................................................................166

SECTION VI. Transcendental Idealism as the Key to the Solution of Pure Cosmological

Dialectic...............................................................................................................................................168

SECTION VII. Critical Solution of the Cosmological Problem........................................................169

SECTION VIII. Regulative Principle of Pure Reason in relation to the Cosmological Ideas. ...........172

SECTION IX. Of the Empirical Use of the Regulative Principle of Reason with regard to the

Cosmological Ideas. .............................................................................................................................174

CHAPTER III. The Ideal of Pure Reason. ..........................................................................................189

SECTION I. Of the Ideal in General..................................................................................................189

SECTION II. Of the Transcendental Ideal (Prototypon Trancendentale)..........................................190

SECTION III. Of the Arguments employed by Speculative Reason in Proof of the Existence of

a Supreme Being. .................................................................................................................................194

SECTION IV. Of the Impossibility of an Ontological Proof of the Existence of God.......................196

SECTION V. Of the Impossibility of a Cosmological Proof of the Existence of God......................200

SECTION VI. Of the Impossibility of a PhysicoTheological Proof.................................................205

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason...................208

CHAPTER I. The Discipline of Pure Reason. ....................................................................................230

SECTION I. The Discipline of Pure Reason in the Sphere of Dogmatism........................................231

SECTION II. The Discipline of Pure Reason in Polemics.................................................................239

SECTION III. The Discipline of Pure Reason in Hypothesis............................................................248

SECTION IV. The Discipline of Pure Reason in Relation to Proofs.................................................251

CHAPTER II. The Canon of Pure Reason. .........................................................................................255

SECTION I. Of the Ultimate End of the Pure Use of Reason. ...........................................................255

SECTION II. Of the Ideal of the Summum Bonum as a Determining Ground of the Ultimate

End of Pure Reason. .............................................................................................................................257

SECTION III. Of Opinion, Knowledge, and Belief...........................................................................262

CHAPTER III. The Architectonic of Pure Reason. ............................................................................266

CHAPTER IV. The History of Pure Reason......................................................................................271

Chapter I. Of the Transcendental Clue to the Discovery of all Pure Conceptions of the Understanding.

Section II. Transcendental Deduction of the pure Conceptions of the Understanding.

Section III. Systematic Representation of all Synthetical Principles of the Pure Understanding.

Chapter III. Of the Ground of the Division of all Objects into Phenomena and Noumena

Section IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its Transcendental

Section V. Sceptical Exposition of the Cosmological Problems presented in the four Transcendental Ideas

Section VI. Transcendental Idealism as the Key to the Solution of Pure Cosmological Dialectic

Section VIII. Regulative Principle of Pure Reason in relation to the Cosmological Ideas

Section IX. Of the Empirical Use of the Regulative Principle of Reason with regard to the Cosmological

Section III. Of the Arguments employed by Speculative Reason in Proof of the Existence of a Supreme

Section IV. Of the Impossibility of an Ontological Proof of the Existence of God

Section VII. Critique of all Theology based upon Speculative Principles of Reason

Section II. Of the Ideal of the Summum Bonum as a Determining Ground of the Ultimate End of Pure

Human reason, in one sphere of its cognition, is called upon to consider questions, which it cannot decline, as

they are presented by its own nature, but which it cannot answer, as they transcend every faculty of the mind.

It falls into this difficulty without any fault of its own. It begins with principles, which cannot be dispensed

with in the field of experience, and the truth and sufficiency of which are, at the same time, insured by

experience. With these principles it rises, in obedience to the laws of its own nature, to ever higher and more

remote conditions. But it quickly discovers that, in this way, its labours must remain ever incomplete,

because new questions never cease to present themselves; and thus it finds itself compelled to have recourse

to principles which transcend the region of experience, while they are regarded by common sense without

distrust. It thus falls into confusion and contradictions, from which it conjectures the presence of latent errors,

which, however, it is unable to discover, because the principles it employs, transcending the limits of

experience, cannot be tested by that criterion. The arena of these endless contests is called Metaphysic.

Time was, when she was the queen of all the sciences; and, if we take the will for the deed, she certainly

deserves, so far as regards the high importance of her objectmatter, this title of honour. Now, it is the

fashion of the time to heap contempt and scorn upon her; and the matron mourns, forlorn and forsaken, like

*Ovid, Metamorphoses. [xiii, "But late on the pinnacle of fame, strong in my many sons. now exiled,

At first, her government, under the administration of the dogmatists, was an absolute despotism. But, as the

legislative continued to show traces of the ancient barbaric rule, her empire gradually broke up, and intestine

wars introduced the reign of anarchy; while the sceptics, like nomadic tribes, who hate a permanent

habitation and settled mode of living, attacked from time to time those who had organized themselves into

civil communities. But their number was, very happily, small; and thus they could not entirely put a stop to

the exertions of those who persisted in raising new edifices, although on no settled or uniform plan. In recent

times the hope dawned upon us of seeing those disputes settled, and the legitimacy of her claims established

by a kind of physiology of the human understanding that of the celebrated Locke. But it was found that

although it was affirmed that this socalled queen could not refer her descent to any higher source than that

of common experience, a circumstance which necessarily brought suspicion on her claims as this genealogy

was incorrect, she persisted in the advancement of her claims to sovereignty. Thus metaphysics necessarily

fell back into the antiquated and rotten constitution of dogmatism, and again became obnoxious to the

contempt from which efforts had been made to save it. At present, as all methods, according to the general

persuasion, have been tried in vain, there reigns nought but weariness and complete indifferentism the

mother of chaos and night in the scientific world, but at the same time the source of, or at least the prelude to,

the recreation and reinstallation of a science, when it has fallen into confusion, obscurity, and disuse from ill

For it is in reality vain to profess indifference in regard to such inquiries, the object of which cannot be

indifferent to humanity. Besides, these pretended indifferentists, however much they may try to disguise

themselves by the assumption of a popular style and by changes on the language of the schools, unavoidably

fall into metaphysical declarations and propositions, which they profess to regard with so much contempt. At

the same time, this indifference, which has arisen in the world of science, and which relates to that kind of

knowledge which we should wish to see destroyed the last, is a phenomenon that well deserves our attention

and reflection. It is plainly not the effect of the levity, but of the matured judgement* of the age, which

refuses to be any longer entertained with illusory knowledge, It is, in fact, a call to reason, again to undertake

the most laborious of all tasks that of selfexamination and to establish a tribunal, which may secure it in

its wellgrounded claims, while it pronounces against all baseless assumptions and pretensions, not in an

arbitrary manner, but according to its own eternal and unchangeable laws. This tribunal is nothing less than

*We very often hear complaints of the shallowness of the present age, and of the decay of profound science.

But I do not think that those which rest upon a secure foundation, such as mathematics, physical science, etc.,

in the least deserve this reproach, but that they rather maintain their ancient fame, and in the latter case,

indeed, far surpass it. The same would be the case with the other kinds of cognition, if their principles were

but firmly established. In the absence of this security, indifference, doubt, and finally, severe criticism are

rather signs of a profound habit of thought. Our age is the age of criticism, to which everything must be

subjected. The sacredness of religion, and the authority of legislation, are by many regarded as grounds of

exemption from the examination of this tribunal. But, if they on they are exempted, they become the subjects

of just suspicion, and cannot lay claim to sincere respect, which reason accords only to that which has stood

I do not mean by this a criticism of books and systems, but a critical inquiry into the faculty of reason, with

reference to the cognitions to which it strives to attain without the aid of experience; in other words, the

solution of the question regarding the possibility or impossibility of metaphysics, and the determination of the

origin, as well as of the extent and limits of this science. All this must be done on the basis of principles.

This path the only one now remaining has been entered upon by me; and I flatter myself that I have, in this

way, discovered the cause of and consequently the mode of removing all the errors which have hitherto set

reason at variance with itself, in the sphere of nonempirical thought. I have not returned an evasive answer

to the questions of reason, by alleging the inability and limitation of the faculties of the mind; I have, on the

contrary, examined them completely in the light of principles, and, after having discovered the cause of the

doubts and contradictions into which reason fell, have solved them to its perfect satisfaction. It is true, these

questions have not been solved as dogmatism, in its vain fancies and desires, had expected; for it can only be

satisfied by the exercise of magical arts, and of these I have no knowledge. But neither do these come within

the compass of our mental powers; and it was the duty of philosophy to destroy the illusions which had their

origin in misconceptions, whatever darling hopes and valued expectations may be ruined by its explanations.

My chief aim in this work has been thoroughness; and I make bold to say that there is not a single

metaphysical problem that does not find its solution, or at least the key to its solution, here. Pure reason is a

perfect unity; and therefore, if the if the principle presented by it prove to be insufficient for the solution of

even a single one of those questions to which the very nature of reason gives birth, we must reject it, as we

While I say this, I think I see upon the countenance of the reader signs of dissatisfaction mingled with

contempt, when he hears declarations which sound so boastful and extravagant; and yet they are beyond

comparison more moderate than those advanced by the commonest author of the commonest philosophical

programme, in which the dogmatist professes to demonstrate the simple nature of the soul, or the necessity of

a primal being. Such a dogmatist promises to extend human knowledge beyond the limits of possible

experience; while I humbly confess that this is completely beyond my power. Instead of any such attempt, I

confine myself to the examination of reason alone and its pure thought; and I do not need to seek far for the

sumtotal of its cognition, because it has its seat in my own mind. Besides, common logic presents me with a

complete and systematic catalogue of all the simple operations of reason; and it is my task to answer the

question how far reason can go, without the material presented and the aid furnished by experience.

So much for the completeness and thoroughness necessary in the execution of the present task. The aims set

before us are not arbitrarily proposed, but are imposed upon us by the nature of cognition itself.

The above remarks relate to the matter of our critical inquiry. As regards the form, there are two

indispensable conditions, which any one who undertakes so difficult a task as that of a critique of pure

As regards certitude, I have fully convinced myself that, in this sphere of thought, opinion is perfectly

inadmissible, and that everything which bears the least semblance of an hypothesis must be excluded, as of

no value in such discussions. For it is a necessary condition of every cognition that is to be established upon a

priori grounds that it shall be held to be absolutely necessary; much more is this the case with an attempt to

determine all pure a priori cognition, and to furnish the standard and consequently an example of all

apodeictic (philosophical) certitude. Whether I have succeeded in what I professed to do, it is for the reader to

determine; it is the author's business merely to adduce grounds and reasons, without determining what

influence these ought to have on the mind of his judges. But, lest anything he may have said may become the

innocent cause of doubt in their minds, or tend to weaken the effect which his arguments might otherwise

produce he may be allowed to point out those passages which may occasion mistrust or difficulty, although

these do not concern the main purpose of the present work. He does this solely with the view of removing

from the mind of the reader any doubts which might affect his judgement of the work as a whole, and in

I know no investigations more necessary for a full insight into the nature of the faculty which we call

understanding, and at the same time for the determination of the rules and limits of its use, than those

undertaken in the second chapter of the "Transcendental Analytic," under the title of "Deduction of the Pure

Conceptions of the Understanding"; and they have also cost me by far the greatest labour labour which, I

hope, will not remain uncompensated. The view there taken, which goes somewhat deeply into the subject,

has two sides, The one relates to the objects of the pure understanding, and is intended to demonstrate and to

render comprehensible the objective validity of its a priori conceptions; and it forms for this reason an

essential part of the Critique. The other considers the pure understanding itself, its possibility and its powers

of cognition that is, from a subjective point of view; and, although this exposition is of great importance, it

does not belong essentially to the main purpose of the work, because the grand question is what and how

much can reason and understanding, apart from experience, cognize, and not, how is the faculty of thought

itself possible? As the latter is an, inquiry into the cause of a given effect, and has thus in it some semblance

of an hypothesis (although, as I shall show on another occasion, this is really not the fact), it would seem that,

in the present instance, I had allowed myself to enounce a mere opinion, and that the reader must therefore be

at liberty to hold a different opinion. But I beg to remind him that, if my subjective deduction does not

produce in his mind the conviction of its certitude at which I aimed, the objective deduction, with which

As regards clearness, the reader has a right to demand, in the first place, discursive or logical clearness, that

is, on the basis of conceptions, and, secondly, intuitive or aesthetic clearness, by means of intuitions, that is,

by examples or other modes of illustration in concreto. I have done what I could for the first kind of

intelligibility. This was essential to my purpose; and it thus became the accidental cause of my inability to do

complete justice to the second requirement. I have been almost always at a loss, during the progress of this

work, how to settle this question. Examples and illustrations always appeared to me necessary, and, in the

first sketch of the Critique, naturally fell into their proper places. But I very soon became aware of the

magnitude of my task, and the numerous problems with which I should be engaged; and, as I perceived that

this critical investigation would, even if delivered in the driest scholastic manner, be far from being brief, I

found it unadvisable to enlarge it still more with examples and explanations, which are necessary only from a

popular point of view. I was induced to take this course from the consideration also that the present work is

not intended for popular use, that those devoted to science do not require such helps, although they are

always acceptable, and that they would have materially interfered with my present purpose. Abbe Terrasson

remarks with great justice that, if we estimate the size of a work, not from the number of its pages, but from

the time which we require to make ourselves master of it, it may be said of many a book that it would be

much shorter, if it were not so short. On the other hand, as regards the comprehensibility of a system of

speculative cognition, connected under a single principle, we may say with equal justice: many a book would

have been much clearer, if it had not been intended to be so very clear. For explanations and examples, and

other helps to intelligibility, aid us in the comprehension of parts, but they distract the attention, dissipate the

mental power of the reader, and stand in the way of his forming a clear conception of the whole; as he cannot

attain soon enough to a survey of the system, and the colouring and embellishments bestowed upon it prevent

his observing its articulation or organization which is the most important consideration with him, when he

The reader must naturally have a strong inducement to cooperate with the present author, if he has formed

the intention of erecting a complete and solid edifice of metaphysical science, according to the plan now laid

before him. Metaphysics, as here represented, is the only science which admits of completion and with little

labour, if it is united, in a short time; so that nothing will be left to future generations except the task of

illustrating and applying it didactically. For this science is nothing more than the inventory of all that is given

us by pure reason, systematically arranged. Nothing can escape our notice; for what reason produces from

itself cannot lie concealed, but must be brought to the light by reason itself, so soon as we have discovered

the common principle of the ideas we seek. The perfect unity of this kind of cognitions, which are based upon

pure conceptions, and uninfluenced by any empirical element, or any peculiar intuition leading to determinate

*Persius. [Satirae iv. 52. "Dwell with yourself, and you will know how short your household stuff is."

Such a system of pure speculative reason I hope to be able to publish under the title of Metaphysic of Nature.

The content of this work (which will not be half so long) will be very much richer than that of the present

Critique, which has to discover the sources of this cognition and expose the conditions of its possibility, and

at the same time to clear and level a fit foundation for the scientific edifice. In the present work, I look for the

patient hearing and the impartiality of a judge; in the other, for the goodwill and assistance of a colabourer.

For, however complete the list of principles for this system may be in the Critique, the correctness of the

system requires that no deduced conceptions should be absent. These cannot be presented a priori, but must

be gradually discovered; and, while the synthesis of conceptions has been fully exhausted in the Critique, it is

necessary that, in the proposed work, the same should be the case with their analysis. But this will be rather

Whether the treatment of that portion of our knowledge which lies within the province of pure reason

advances with that undeviating certainty which characterizes the progress of science, we shall be at no loss to

determine. If we find those who are engaged in metaphysical pursuits, unable to come to an understanding as

to the method which they ought to follow; if we find them, after the most elaborate preparations, invariably

brought to a stand before the goal is reached, and compelled to retrace their steps and strike into fresh paths,

we may then feel quite sure that they are far from having attained to the certainty of scientific progress and

may rather be said to be merely groping about in the dark. In these circumstances we shall render an

important service to reason if we succeed in simply indicating the path along which it must travel, in order to

arrive at any results even if it should be found necessary to abandon many of those aims which, without

That logic has advanced in this sure course, even from the earliest times, is apparent from the fact that, since

Aristotle, it has been unable to advance a step and, thus, to all appearance has reached its completion. For, if

some of the moderns have thought to enlarge its domain by introducing psychological discussions on the

mental faculties, such as imagination and wit, metaphysical, discussions on the origin of knowledge and the

different kinds of certitude, according to the difference of the objects (idealism, scepticism, and so on), or

anthropological discussions on prejudices, their causes and remedies: this attempt, on the part of these

authors, only shows their ignorance of the peculiar nature of logical science. We do not enlarge but disfigure

the sciences when we lose sight of their respective limits and allow them to run into one another. Now logic

is enclosed within limits which admit of perfectly clear definition; it is a science which has for its object

nothing but the exposition and proof of the formal laws of all thought, whether it be a priori or empirical,

whatever be its origin or its object, and whatever the difficulties natural or accidental which it encounters

The early success of logic must be attributed exclusively to the narrowness of its field, in which abstraction

may, or rather must, be made of all the objects of cognition with their characteristic distinctions, and in which

the understanding has only to deal with itself and with its own forms. It is, obviously, a much more difficult

task for reason to strike into the sure path of science, where it has to deal not simply with itself, but with

objects external to itself. Hence, logic is properly only a propaedeutic forms, as it were, the vestibule of the

sciences; and while it is necessary to enable us to form a correct judgement with regard to the various

branches of knowledge, still the acquisition of real, substantive knowledge is to be sought only in the

Now these sciences, if they can be termed rational at all, must contain elements of a priori cognition, and this

cognition may stand in a twofold relation to its object. Either it may have to determine the conception of the

object which must be supplied extraneously, or it may have to establish its reality. The former is theoretical,

the latter practical, rational cognition. In both, the pure or a priori element must be treated first, and must be

carefully distinguished from that which is supplied from other sources. Any other method can only lead to

Mathematics and physics are the two theoretical sciences which have to determine their objects a priori. The

former is purely a priori, the latter is partially so, but is also dependent on other sources of cognition.

In the earliest times of which history affords us any record, mathematics had already entered on the sure

course of science, among that wonderful nation, the Greeks. Still it is not to be supposed that it was as easy

for this science to strike into, or rather to construct for itself, that royal road, as it was for logic, in which

reason has only to deal with itself. On the contrary, I believe that it must have remained long chiefly among

the Egyptians in the stage of blind groping after its true aims and destination, and that it was revolutionized

by the happy idea of one man, who struck out and determined for all time the path which this science must

follow, and which admits of an indefinite advancement. The history of this intellectual revolution much

more important in its results than the discovery of the passage round the celebrated Cape of Good Hope and

of its author, has not been preserved. But Diogenes Laertius, in naming the supposed discoverer of some of

the simplest elements of geometrical demonstration elements which, according to the ordinary opinion, do

not even require to be proved makes it apparent that the change introduced by the first indication of this new

path, must have seemed of the utmost importance to the mathematicians of that age, and it has thus been

secured against the chance of oblivion. A new light must have flashed on the mind of the first man (Thales, or

whatever may have been his name) who demonstrated the properties of the isosceles triangle. For he found

that it was not sufficient to meditate on the figure, as it lay before his eyes, or the conception of it, as it

existed in his mind, and thus endeavour to get at the knowledge of its properties, but that it was necessary to

produce these properties, as it were, by a positive a priori construction; and that, in order to arrive with

certainty at a priori cognition, he must not attribute to the object any other properties than those which

necessarily followed from that which he had himself, in accordance with his conception, placed in the object.

A much longer period elapsed before physics entered on the highway of science. For it is only about a

century and a half since the wise Bacon gave a new direction to physical studies, or rather as others were

already on the right track imparted fresh vigour to the pursuit of this new direction. Here, too, as in the case

of mathematics, we find evidence of a rapid intellectual revolution. In the remarks which follow I shall

When Galilei experimented with balls of a definite weight on the inclined plane, when Torricelli caused the

air to sustain a weight which he had calculated beforehand to be equal to that of a definite column of water,

or when Stahl, at a later period, converted metals into lime, and reconverted lime into metal, by the addition

and subtraction of certain elements;* a light broke upon all natural philosophers. They learned that reason

only perceives that which it produces after its own design; that it must not be content to follow, as it were, in

the leadingstrings of nature, but must proceed in advance with principles of judgement according to

unvarying laws, and compel nature to reply its questions. For accidental observations, made according to no

preconceived plan, cannot be united under a necessary law. But it is this that reason seeks for and requires. It

is only the principles of reason which can give to concordant phenomena the validity of laws, and it is only

when experiment is directed by these rational principles that it can have any real utility. Reason must

approach nature with the view, indeed, of receiving information from it, not, however, in the character of a

pupil, who listens to all that his master chooses to tell him, but in that of a judge, who compels the witnesses

to reply to those questions which he himself thinks fit to propose. To this single idea must the revolution be

ascribed, by which, after groping in the dark for so many centuries, natural science was at length conducted

*I do not here follow with exactness the history of the experimental method, of which, indeed, the first steps

We come now to metaphysics, a purely speculative science, which occupies a completely isolated position

and is entirely independent of the teachings of experience. It deals with mere conceptions not, like

mathematics, with conceptions applied to intuition and in it, reason is the pupil of itself alone. It is the oldest

of the sciences, and would still survive, even if all the rest were swallowed up in the abyss of an

alldestroying barbarism. But it has not yet had the good fortune to attain to the sure scientific method. This

will be apparent; if we apply the tests which we proposed at the outset. We find that reason perpetually comes

to a stand, when it attempts to gain a priori the perception even of those laws which the most common

experience confirms. We find it compelled to retrace its steps in innumerable instances, and to abandon the

path on which it had entered, because this does not lead to the desired result. We find, too, that those who are

engaged in metaphysical pursuits are far from being able to agree among themselves, but that, on the

contrary, this science appears to furnish an arena specially adapted for the display of skill or the exercise of

strength in mockcontests a field in which no combatant ever yet succeeded in gaining an inch of ground, in

This leads us to inquire why it is that, in metaphysics, the sure path of science has not hitherto been found.

Shall we suppose that it is impossible to discover it? Why then should nature have visited our reason with

restless aspirations after it, as if it were one of our weightiest concerns? Nay, more, how little cause should

we have to place confidence in our reason, if it abandons us in a matter about which, most of all, we desire to

know the truth and not only so, but even allures us to the pursuit of vain phantoms, only to betray us in the

end? Or, if the path has only hitherto been missed, what indications do we possess to guide us in a renewed

investigation, and to enable us to hope for greater success than has fallen to the lot of our predecessors?

It appears to me that the examples of mathematics and natural philosophy, which, as we have seen, were

brought into their present condition by a sudden revolution, are sufficiently remarkable to fix our attention on

the essential circumstances of the change which has proved so advantageous to them, and to induce us to

make the experiment of imitating them, so far as the analogy which, as rational sciences, they bear to

metaphysics may permit. It has hitherto been assumed that our cognition must conform to the objects; but all

attempts to ascertain anything about these objects a priori, by means of conceptions, and thus to extend the

range of our knowledge, have been rendered abortive by this assumption. Let us then make the experiment

whether we may not be more successful in metaphysics, if we assume that the objects must conform to our

cognition. This appears, at all events, to accord better with the possibility of our gaining the end we have in

view, that is to say, of arriving at the cognition of objects a priori, of determining something with respect to

these objects, before they are given to us. We here propose to do just what Copernicus did in attempting to

explain the celestial movements. When he found that he could make no progress by assuming that all the

heavenly bodies revolved round the spectator, he reversed the process, and tried the experiment of assuming

that the spectator revolved, while the stars remained at rest. We may make the same experiment with regard

to the intuition of objects. If the intuition must conform to the nature of the objects, I do not see how we can

know anything of them a priori. If, on the other hand, the object conforms to the nature of our faculty of

intuition, I can then easily conceive the possibility of such an a priori knowledge. Now as I cannot rest in the

mere intuitions, but if they are to become cognitions must refer them, as representations, to something, as

object, and must determine the latter by means of the former, here again there are two courses open to me.

Either, first, I may assume that the conceptions, by which I effect this determination, conform to the object

and in this case I am reduced to the same perplexity as before; or secondly, I may assume that the objects, or,

which is the same thing, that experience, in which alone as given objects they are cognized, conform to my

conceptions and then I am at no loss how to proceed. For experience itself is a mode of cognition which

requires understanding. Before objects, are given to me, that is, a priori, I must presuppose in myself laws of

the understanding which are expressed in conceptions a priori. To these conceptions, then, all the objects of

experience must necessarily conform. Now there are objects which reason thinks, and that necessarily, but

which cannot be given in experience, or, at least, cannot be given so as reason thinks them. The attempt to

think these objects will hereafter furnish an excellent test of the new method of thought which we have

adopted, and which is based on the principle that we only cognize in things a priori that which we ourselves

*This method, accordingly, which we have borrowed from the natural philosopher, consists in seeking for the

elements of pure reason in that which admits of confirmation or refutation by experiment. Now the

propositions of pure reason, especially when they transcend the limits of possible experience, do not admit of

our making any experiment with their objects, as in natural science. Hence, with regard to those conceptions

and principles which we assume a priori, our only course ill be to view them from two different sides. We

must regard one and the same conception, on the one hand, in relation to experience as an object of the senses

and of the understanding, on the other hand, in relation to reason, isolated and transcending the limits of

experience, as an object of mere thought. Now if we find that, when we regard things from this double point

of view, the result is in harmony with the principle of pure reason, but that, when we regard them from a

single point of view, reason is involved in selfcontradiction, then the experiment will establish the

This attempt succeeds as well as we could desire, and promises to metaphysics, in its first part that is, where

it is occupied with conceptions a priori, of which the corresponding objects may be given in experience the

certain course of science. For by this new method we are enabled perfectly to explain the possibility of a

priori cognition, and, what is more, to demonstrate satisfactorily the laws which lie a priori at the foundation

of nature, as the sum of the objects of experience neither of which was possible according to the procedure

hitherto followed. But from this deduction of the faculty of a priori cognition in the first part of metaphysics,

we derive a surprising result, and one which, to all appearance, militates against the great end of metaphysics,

as treated in the second part. For we come to the conclusion that our faculty of cognition is unable to

transcend the limits of possible experience; and yet this is precisely the most essential object of this science.

The estimate of our rational cognition a priori at which we arrive is that it has only to do with phenomena,

and that things in themselves, while possessing a real existence, lie beyond its sphere. Here we are enabled to

put the justice of this estimate to the test. For that which of necessity impels us to transcend the limits of

experience and of all phenomena is the unconditioned, which reason absolutely requires in things as they are

in themselves, in order to complete the series of conditions. Now, if it appears that when, on the one hand, we

assume that our cognition conforms to its objects as things in themselves, the unconditioned cannot be

thought without contradiction, and that when, on the other hand, we assume that our representation of things

as they are given to us, does not conform to these things as they are in themselves, but that these objects, as

phenomena, conform to our mode of representation, the contradiction disappears: we shall then be convinced

of the truth of that which we began by assuming for the sake of experiment; we may look upon it as

established that the unconditioned does not lie in things as we know them, or as they are given to us, but in

*This experiment of pure reason has a great similarity to that of the chemists, which they term the experiment

of reduction, or, more usually, the synthetic process. The analysis of the metaphysician separates pure

cognition a priori into two heterogeneous elements, viz., the cognition of things as phenomena, and of things

in themselves. Dialectic combines these again into harmony with the necessary rational idea of the

unconditioned, and finds that this harmony never results except through the above distinction, which is,

But, after we have thus denied the power of speculative reason to make any progress in the sphere of the

supersensible, it still remains for our consideration whether data do not exist in practical cognition which may

enable us to determine the transcendent conception of the unconditioned, to rise beyond the limits of all

possible experience from a practical point of view, and thus to satisfy the great ends of metaphysics.

Speculative reason has thus, at least, made room for such an extension of our knowledge: and, if it must leave

this space vacant, still it does not rob us of the liberty to fill it up, if we can, by means of practical data nay,

*So the central laws of the movements of the heavenly bodies established the truth of that which Copernicus,

first, assumed only as a hypothesis, and, at the same time, brought to light that invisible force (Newtonian

attraction) which holds the universe together. The latter would have remained forever undiscovered, if

Copernicus had not ventured on the experiment contrary to the senses but still just of looking for the

observed movements not in the heavenly bodies, but in the spectator. In this Preface I treat the new

metaphysical method as a hypothesis with the view of rendering apparent the first attempts at such a change

of method, which are always hypothetical. But in the Critique itself it will be demonstrated, not

hypothetically, but apodeictically, from the nature of our representations of space and time. and from the

This attempt to introduce a complete revolution in the procedure of metaphysics, after the example of the

geometricians and natural philosophers, constitutes the aim of the Critique of Pure Speculative Reason. It is a

treatise on the method to be followed, not a system of the science itself. But, at the same time, it marks out

and defines both the external boundaries and the internal structure of this science. For pure speculative reason

has this peculiarity, that, in choosing the various objects of thought, it is able to define the limits of its own

faculties, and even to give a complete enumeration of the possible modes of proposing problems to itself, and

thus to sketch out the entire system of metaphysics. For, on the one hand, in cognition a priori, nothing must

be attributed to the objects but what the thinking subject derives from itself; and, on the other hand, reason is,

in regard to the principles of cognition, a perfectly distinct, independent unity, in which, as in an organized

body, every member exists for the sake of the others, and all for the sake of each, so that no principle can be

viewed, with safety, in one relationship, unless it is, at the same time, viewed in relation to the total use of

pure reason. Hence, too, metaphysics has this singular advantage an advantage which falls to the lot of no

other science which has to do with objects that, if once it is conducted into the sure path of science, by

means of this criticism, it can then take in the whole sphere of its cognitions, and can thus complete its work,

and leave it for the use of posterity, as a capital which can never receive fresh accessions. For metaphysics

has to deal only with principles and with the limitations of its own employment as determined by these

principles. To this perfection it is, therefore, bound, as the fundamental science, to attain, and to it the maxim

But, it will be asked, what kind of a treasure is this that we propose to bequeath to posterity? What is the real

value of this system of metaphysics, purified by criticism, and thereby reduced to a permanent condition? A

cursory view of the present work will lead to the supposition that its use is merely negative, that it only serves

to warn us against venturing, with speculative reason, beyond the limits of experience. This is, in fact, its

primary use. But this, at once, assumes a positive value, when we observe that the principles with which

speculative reason endeavours to transcend its limits lead inevitably, not to the extension, but to the

contraction of the use of reason, inasmuch as they threaten to extend the limits of sensibility, which is their

proper sphere, over the entire realm of thought and, thus, to supplant the pure (practical) use of reason. So far,

then, as this criticism is occupied in confining speculative reason within its proper bounds, it is only negative;

but, inasmuch as it thereby, at the same time, removes an obstacle which impedes and even threatens to

destroy the use of practical reason, it possesses a positive and very important value. In order to admit this, we

have only to be convinced that there is an absolutely necessary use of pure reason the moral use in which it

inevitably transcends the limits of sensibility, without the aid of speculation, requiring only to be insured

against the effects of a speculation which would involve it in contradiction with itself. To deny the positive

advantage of the service which this criticism renders us would be as absurd as. to maintain that the system of

police is productive of no positive benefit, since its main business is to prevent the violence which citizen has

to apprehend from citizen, that so each may pursue his vocation in peace and security. That space and time

are only forms of sensible intuition, and hence are only conditions of the existence of things as phenomena;

that, moreover, we have no conceptions of the understanding, and, consequently, no elements for the

cognition of things, except in so far as a corresponding intuition can be given to these conceptions; that,

accordingly, we can have no cognition of an object, as a thing in itself, but only as an object of sensible

intuition, that is, as phenomenon all this is proved in the analytical part of the Critique; and from this the

limitation of all possible speculative cognition to the mere objects of experience, follows as a necessary

result. At the same time, it must be carefully borne in mind that, while we surrender the power of cognizing,

we still reserve the power of thinking objects, as things in themselves.* For, otherwise, we should require to

affirm the existence of an appearance, without something that appears which would be absurd. Now let us

suppose, for a moment, that we had not undertaken this criticism and, accordingly, had not drawn the

necessary distinction between things as objects of experience and things as they are in themselves. The

principle of causality, and, by consequence, the mechanism of nature as determined by causality, would then

have absolute validity in relation to all things as efficient causes. I should then be unable to assert, with

regard to one and the same being, e.g., the human soul, that its will is free, and yet, at the same time, subject

to natural necessity, that is, not free, without falling into a palpable contradiction, for in both propositions I

should take the soul in the same signification, as a thing in general, as a thing in itself as, without previous

criticism, I could not but take it. Suppose now, on the other hand, that we have undertaken this criticism, and

have learnt that an object may be taken in two senses, first, as a phenomenon, secondly, as a thing in itself;

and that, according to the deduction of the conceptions of the understanding, the principle of causality has

reference only to things in the first sense. We then see how it does not involve any contradiction to assert, on

the one hand, that the will, in the phenomenal sphere in visible action is necessarily obedient to the law of

nature, and, in so far, not free; and, on the other hand, that, as belonging to a thing in itself, it is not subject to

that law, and, accordingly, is free. Now, it is true that I cannot, by means of speculative reason, and still less

by empirical observation, cognize my soul as a thing in itself and consequently, cannot cognize liberty as the

property of a being to which I ascribe effects in the world of sense. For, to do so, I must cognize this being as

existing, and yet not in time, which since I cannot support my conception by any intuition is impossible.

At the same time, while I cannot cognize, I can quite well think freedom, that is to say, my representation of

it involves at least no contradiction, if we bear in mind the critical distinction of the two modes of

representation (the sensible and the intellectual) and the consequent limitation of the conceptions of the pure

understanding and of the principles which flow from them. Suppose now that morality necessarily

presupposed liberty, in the strictest sense, as a property of our will; suppose that reason contained certain

practical, original principles a priori, which were absolutely impossible without this presupposition; and

suppose, at the same time, that speculative reason had proved that liberty was incapable of being thought at

all. It would then follow that the moral presupposition must give way to the speculative affirmation, the

opposite of which involves an obvious contradiction, and that liberty and, with it, morality must yield to the

mechanism of nature; for the negation of morality involves no contradiction, except on the presupposition of

liberty. Now morality does not require the speculative cognition of liberty; it is enough that I can think it, that

its conception involves no contradiction, that it does not interfere with the mechanism of nature. But even this

requirement we could not satisfy, if we had not learnt the twofold sense in which things may be taken; and it

is only in this way that the doctrine of morality and the doctrine of nature are confined within their proper

limits. For this result, then, we are indebted to a criticism which warns us of our unavoidable ignorance with

regard to things in themselves, and establishes the necessary limitation of our theoretical cognition to mere

*In order to cognize an object, I must be able to prove its possibility, either from its reality as attested by

experience, or a priori, by means of reason. But I can think what I please, provided only I do not contradict

myself; that is, provided my conception is a possible thought, though I may be unable to answer for the

existence of a corresponding object in the sum of possibilities. But something more is required before I can

attribute to such a conception objective validity, that is real possibility the other possibility being merely

logical. We are not, however, confined to theoretical sources of cognition for the means of satisfying this

The positive value of the critical principles of pure reason in relation to the conception of God and of the

simple nature of the soul, admits of a similar exemplification; but on this point I shall not dwell. I cannot

even make the assumption as the practical interests of morality require of God, freedom, and immortality,

if I do not deprive speculative reason of its pretensions to transcendent insight. For to arrive at these, it must

make use of principles which, in fact, extend only to the objects of possible experience, and which cannot be

applied to objects beyond this sphere without converting them into phenomena, and thus rendering the

practical extension of pure reason impossible. I must, therefore, abolish knowledge, to make room for belief.

The dogmatism of metaphysics, that is, the presumption that it is possible to advance in metaphysics without

previous criticism, is the true source of the unbelief (always dogmatic) which militates against morality.

Thus, while it may be no very difficult task to bequeath a legacy to posterity, in the shape of a system of

metaphysics constructed in accordance with the Critique of Pure Reason, still the value of such a bequest is

not to be depreciated. It will render an important service to reason, by substituting the certainty of scientific

method for that random groping after results without the guidance of principles, which has hitherto

characterized the pursuit of metaphysical studies. It will render an important service to the inquiring mind of

youth, by leading the student to apply his powers to the cultivation of. genuine science, instead of wasting

them, as at present, on speculations which can never lead to any result, or on the idle attempt to invent new

ideas and opinions. But, above all, it will confer an inestimable benefit on morality and religion, by showing

that all the objections urged against them may be silenced for ever by the Socratic method, that is to say, by

proving the ignorance of the objector. For, as the world has never been, and, no doubt, never will be without a

system of metaphysics of one kind or another, it is the highest and weightiest concern of philosophy to render

This important change in the field of the sciences, this loss of its fancied possessions, to which speculative

reason must submit, does not prove in any way detrimental to the general interests of humanity. The

advantages which the world has derived from the teachings of pure reason are not at all impaired. The loss

falls, in its whole extent, on the monopoly of the schools, but does not in the slightest degree touch the

interests of mankind. I appeal to the most obstinate dogmatist, whether the proof of the continued existence of

the soul after death, derived from the simplicity of its substance; of the freedom of the will in opposition to

the general mechanism of nature, drawn from the subtle but impotent distinction of subjective and objective

practical necessity; or of the existence of God, deduced from the conception of an ens realissimum the

contingency of the changeable, and the necessity of a prime mover, has ever been able to pass beyond the

limits of the schools, to penetrate the public mind, or to exercise the slightest influence on its convictions. It

must be admitted that this has not been the case and that, owing to the unfitness of the common

understanding for such subtle speculations, it can never be expected to take place. On the contrary, it is plain

that the hope of a future life arises from the feeling, which exists in the breast of every man, that the temporal

is inadequate to meet and satisfy the demands of his nature. In like manner, it cannot be doubted that the clear

exhibition of duties in opposition to all the claims of inclination, gives rise to the consciousness of freedom,

and that the glorious order, beauty, and providential care, everywhere displayed in nature, give rise to the

belief in a wise and great Author of the Universe. Such is the genesis of these general convictions of

mankind, so far as they depend on rational grounds; and this public property not only remains undisturbed,

but is even raised to greater importance, by the doctrine that the schools have no right to arrogate to

themselves a more profound insight into a matter of general human concernment than that to which the great

mass of men, ever held by us in the highest estimation, can without difficulty attain, and that the schools

should, therefore, confine themselves to the elaboration of these universally comprehensible and, from a

moral point of view, amply satisfactory proofs. The change, therefore, affects only the arrogant pretensions of

the schools, which would gladly retain, in their own exclusive possession, the key to the truths which they

At the same time it does not deprive the speculative philosopher of his just title to be the sole depositor of a

science which benefits the public without its knowledge I mean, the Critique of Pure Reason. This can never

become popular and, indeed, has no occasion to be so; for finespun arguments in favour of useful truths make

just as little impression on the public mind as the equally subtle objections brought against these truths. On

the other hand, since both inevitably force themselves on every man who rises to the height of speculation, it

becomes the manifest duty of the schools to enter upon a thorough investigation of the rights of speculative

reason and, thus, to prevent the scandal which metaphysical controversies are sure, sooner or later, to cause

even to the masses. It is only by criticism that metaphysicians (and, as such, theologians too) can be saved

from these controversies and from the consequent perversion of their doctrines. Criticism alone can strike a

blow at the root of materialism, fatalism, atheism, freethinking, fanaticism, and superstition, which are

universally injurious as well as of idealism and scepticism, which are dangerous to the schools, but can

scarcely pass over to the public. If governments think proper to interfere with the affairs of the learned, it

would be more consistent with a wise regard for the interests of science, as well as for those of society, to

favour a criticism of this kind, by which alone the labours of reason can be established on a firm basis, than to

support the ridiculous despotism of the schools, which raise a loud cry of danger to the public over the

destruction of cobwebs, of which the public has never taken any notice, and the loss of which, therefore, it

This critical science is not opposed to the dogmatic procedure of reason in pure cognition; for pure cognition

must always be dogmatic, that is, must rest on strict demonstration from sure principles a priori but to

dogmatism, that is, to the presumption that it is possible to make any progress with a pure cognition, derived

from (philosophical) conceptions, according to the principles which reason has long been in the habit of

employing without first inquiring in what way and by what right reason has come into the possession of

these principles. Dogmatism is thus the dogmatic procedure of pure reason without previous criticism of its

own powers, and in opposing this procedure, we must not be supposed to lend any countenance to that

loquacious shallowness which arrogates to itself the name of popularity, nor yet to scepticism, which makes

short work with the whole science of metaphysics. On the contrary, our criticism is the necessary preparation

for a thoroughly scientific system of metaphysics which must perform its task entirely a priori, to the

complete satisfaction of speculative reason, and must, therefore, be treated, not popularly, but scholastically.

In carrying out the plan which the Critique prescribes, that is, in the future system of metaphysics, we must

have recourse to the strict method of the celebrated Wolf, the greatest of all dogmatic philosophers. He was

the first to point out the necessity of establishing fixed principles, of clearly defining our conceptions, and of

subjecting our demonstrations to the most severe scrutiny, instead of rashly jumping at conclusions. The

example which he set served to awaken that spirit of profound and thorough investigation which is not yet

extinct in Germany. He would have been peculiarly well fitted to give a truly scientific character to

metaphysical studies, had it occurred to him to prepare the field by a criticism of the organum, that is, of pure

reason itself. That be failed to perceive the necessity of such a procedure must be ascribed to the dogmatic

mode of thought which characterized his age, and on this point the philosophers of his time, as well as of all

previous times, have nothing to reproach each other with. Those who reject at once the method of Wolf, and

of the Critique of Pure Reason, can have no other aim but to shake off the fetters of science, to change labour

In this second edition, I have endeavoured, as far as possible, to remove the difficulties and obscurity which,

without fault of mine perhaps, have given rise to many misconceptions even among acute thinkers. In the

propositions themselves, and in the demonstrations by which they are supported, as well as in the form and

the entire plan of the work, I have found nothing to alter; which must be attributed partly to the long

examination to which I had subjected the whole before offering it to the public and partly to the nature of the

case. For pure speculative reason is an organic structure in which there is nothing isolated or independent, but

every Single part is essential to all the rest; and hence, the slightest imperfection, whether defect or positive

error, could not fail to betray itself in use. I venture, further, to hope, that this system will maintain the same

unalterable character for the future. I am led to entertain this confidence, not by vanity, but by the evidence

which the equality of the result affords, when we proceed, first, from the simplest elements up to the

complete whole of pure reason and, and then, backwards from the whole to each part. We find that the

attempt to make the slightest alteration, in any part, leads inevitably to contradictions, not merely in this

system, but in human reason itself. At the same time, there is still much room for improvement in the

exposition of the doctrines contained in this work. In the present edition, I have endeavoured to remove

misapprehensions of the aesthetical part, especially with regard to the conception of time; to clear away the

obscurity which has been found in the deduction of the conceptions of the understanding; to supply the

supposed want of sufficient evidence in the demonstration of the principles of the pure understanding; and,

lastly, to obviate the misunderstanding of the paralogisms which immediately precede the rational

psychology. Beyond this point the end of the second main division of the "Transcendental Dialectic" I

have not extended my alterations,* partly from want of time, and partly because I am not aware that any

portion of the remainder has given rise to misconceptions among intelligent and impartial critics, whom I do

not here mention with that praise which is their due, but who will find that their suggestions have been

*The only addition, properly so called and that only in the method of proof which I have made in the

present edition, consists of a new refutation of psychological idealism, and a strict demonstration the only

one possible, as I believe of the objective reality of external intuition. However harmless idealism may be

considered although in reality it is not so in regard to the essential ends of metaphysics, it must still remain

a scandal to philosophy and to the general human reason to be obliged to assume, as an article of mere belief,

the existence of things external to ourselves (from which, yet, we derive the whole material of cognition for

the internal sense), and not to be able to oppose a satisfactory proof to any one who may call it in question.

As there is some obscurity of expression in the demonstration as it stands in the text, I propose to alter the

passage in question as follows: "But this permanent cannot be an intuition in me. For all the determining

grounds of my existence which can be found in me are representations and, as such, do themselves require a

permanent, distinct from them, which may determine my existence in relation to their changes, that is, my

existence in time, wherein they change." It may, probably, be urged in opposition to this proof that, after all, I

am only conscious immediately of that which is in me, that is, of my representation of external things, and

that, consequently, it must always remain uncertain whether anything corresponding to this representation

does or does not exist externally to me. But I am conscious, through internal experience, of my existence in

time (consequently, also, of the determinability of the former in the latter), and that is more than the simple

consciousness of my representation. It is, in fact, the same as the empirical consciousness of my existence,

which can only be determined in relation to something, which, while connected with my existence, is external

to me. This consciousness of my existence in time is, therefore, identical with the consciousness of a relation

to something external to me, and it is, therefore, experience, not fiction, sense, not imagination, which

inseparably connects the external with my internal sense. For the external sense is, in itself, the relation of

intuition to something real, external to me; and the reality of this something, as opposed to the mere

imagination of it, rests solely on its inseparable connection with internal experience as the condition of its

possibility. If with the intellectual consciousness of my existence, in the representation: I am, which

accompanies all my judgements, and all the operations of my understanding, I could, at the same time,

connect a determination of my existence by intellectual intuition, then the consciousness of a relation to

something external to me would not be necessary. But the internal intuition in which alone my existence can

be determined, though preceded by that purely intellectual consciousness, is itself sensible and attached to the

condition of time. Hence this determination of my existence, and consequently my internal experience itself,

must depend on something permanent which is not in me, which can be, therefore, only in something external

to me, to which I must look upon myself as being related. Thus the reality of the external sense is necessarily

connected with that of the internal, in order to the possibility of experience in general; that is, I am just as

certainly conscious that there are things external to me related to my sense as I am that I myself exist as

determined in time. But in order to ascertain to what given intuitions objects, external me, really correspond,

in other words, what intuitions belong to the external sense and not to imagination, I must have recourse, in

every particular case, to those rules according to which experience in general (even internal experience) is

distinguished from imagination, and which are always based on the proposition that there really is an external

experience. We may add the remark that the representation of something permanent in existence, is not the

same thing as the permanent representation; for a representation may be very variable and changing as all

our representations, even that of matter, are and yet refer to something permanent, which must, therefore, be

distinct from all my representations and external to me, the existence of which is necessarily included in the

determination of my own existence, and with it constitutes one experience an experience which would not

even be possible internally, if it were not also at the same time, in part, external. To the question How? we are

no more able to reply, than we are, in general, to think the stationary in time, the coexistence of which with

In attempting to render the exposition of my views as intelligible as possible, I have been compelled to leave

out or abridge various passages which were not essential to the completeness of the work, but which many

readers might consider useful in other respects, and might be unwilling to miss. This trifling loss, which

could not be avoided without swelling the book beyond due limits, may be supplied, at the pleasure of the

reader, by a comparison with the first edition, and will, I hope, be more than compensated for by the greater

I have observed, with pleasure and thankfulness, in the pages of various reviews and treatises, that the spirit

of profound and thorough investigation is not extinct in Germany, though it may have been overborne and

silenced for a time by the fashionable tone of a licence in thinking, which gives itself the airs of genius, and

that the difficulties which beset the paths of criticism have not prevented energetic and acute thinkers from

making themselves masters of the science of pure reason to which these paths conduct a science which is

not popular, but scholastic in its character, and which alone can hope for a lasting existence or possess an

abiding value. To these deserving men, who so happily combine profundity of view with a talent for lucid

exposition a talent which I myself am not conscious of possessing I leave the task of removing any

obscurity which may still adhere to the statement of my doctrines. For, in this case, the danger is not that of

being refuted, but of being misunderstood. For my own part, I must henceforward abstain from controversy,

although I shall carefully attend to all suggestions, whether from friends or adversaries, which may be of use

in the future elaboration of the system of this propaedeutic. As, during these labours, I have advanced pretty

far in years this month I reach my sixtyfourth year it will be necessary for me to economize time, if I am to

carry out my plan of elaborating the metaphysics of nature as well as of morals, in confirmation of the

correctness of the principles established in this Critique of Pure Reason, both speculative and practical; and I

must, therefore, leave the task of clearing up the obscurities of the present work inevitable, perhaps, at the

outset as well as, the defence of the whole, to those deserving men, who have made my system their own. A

philosophical system cannot come forward armed at all points like a mathematical treatise, and hence it may

be quite possible to take objection to particular passages, while the organic structure of the system,

considered as a unity, has no danger to apprehend. But few possess the ability, and still fewer the inclination,

to take a comprehensive view of a new system. By confining the view to particular passages, taking these out

of their connection and comparing them with one another, it is easy to pick out apparent contradictions,

especially in a work written with any freedom of style. These contradictions place the work in an

unfavourable light in the eyes of those who rely on the judgement of others, but are easily reconciled by those

who have mastered the idea of the whole. If a theory possesses stability in itself, the action and reaction

which seemed at first to threaten its existence serve only, in the course of time, to smooth down any

superficial roughness or inequality, and if men of insight, impartiality, and truly popular gifts, turn their

That all our knowledge begins with experience there can be no doubt. For how is it possible that the faculty

of cognition should be awakened into exercise otherwise than by means of objects which affect our senses,

and partly of themselves produce representations, partly rouse our powers of understanding into activity, to

compare to connect, or to separate these, and so to convert the raw material of our sensuous impressions into

a knowledge of objects, which is called experience? In respect of time, therefore, no knowledge of ours is

But, though all our knowledge begins with experience, it by no means follows that all arises out of

experience. For, on the contrary, it is quite possible that our empirical knowledge is a compound of that

which we receive through impressions, and that which the faculty of cognition supplies from itself (sensuous

impressions giving merely the occasion), an addition which we cannot distinguish from the original element

given by sense, till long practice has made us attentive to, and skilful in separating it. It is, therefore, a

question which requires close investigation, and not to be answered at first sight, whether there exists a

knowledge altogether independent of experience, and even of all sensuous impressions? Knowledge of this

kind is called a priori, in contradistinction to empirical knowledge, which has its sources a posteriori, that is,

But the expression, "a priori," is not as yet definite enough adequately to indicate the whole meaning of the

question above started. For, in speaking of knowledge which has its sources in experience, we are wont to

say, that this or that may be known a priori, because we do not derive this knowledge immediately from

experience, but from a general rule, which, however, we have itself borrowed from experience. Thus, if a

man undermined his house, we say, "he might know a priori that it would have fallen;" that is, he needed not

to have waited for the experience that it did actually fall. But still, a priori, he could not know even this much.

For, that bodies are heavy, and, consequently, that they fall when their supports are taken away, must have

By the term "knowledge a priori," therefore, we shall in the sequel understand, not such as is independent of

this or that kind of experience, but such as is absolutely so of all experience. Opposed to this is empirical

knowledge, or that which is possible only a posteriori, that is, through experience. Knowledge a priori is

either pure or impure. Pure knowledge a priori is that with which no empirical element is mixed up. For

example, the proposition, "Every change has a cause," is a proposition a priori, but impure, because change is

The question now is as to a criterion, by which we may securely distinguish a pure from an empirical

cognition. Experience no doubt teaches us that this or that object is constituted in such and such a manner,

but not that it could not possibly exist otherwise. Now, in the first place, if we have a proposition which

contains the idea of necessity in its very conception, it is a if, moreover, it is not derived from any other

proposition, unless from one equally involving the idea of necessity, it is absolutely priori. Secondly, an

empirical judgement never exhibits strict and absolute, but only assumed and comparative universality (by

induction); therefore, the most we can say is so far as we have hitherto observed, there is no exception to

this or that rule. If, on the other hand, a judgement carries with it strict and absolute universality, that is,

admits of no possible exception, it is not derived from experience, but is valid absolutely a priori.

Empirical universality is, therefore, only an arbitrary extension of validity, from that which may be

predicated of a proposition valid in most cases, to that which is asserted of a proposition which holds good in

all; as, for example, in the affirmation, "All bodies are heavy." When, on the contrary, strict universality

characterizes a judgement, it necessarily indicates another peculiar source of knowledge, namely, a faculty of

cognition a priori. Necessity and strict universality, therefore, are infallible tests for distinguishing pure from

empirical knowledge, and are inseparably connected with each other. But as in the use of these criteria the

empirical limitation is sometimes more easily detected than the contingency of the judgement, or the

unlimited universality which we attach to a judgement is often a more convincing proof than its necessity, it

II. The Human Intellect, even in an Unphilosophical State, is in Possession of Certain Cognitions "a priori". 16

may be advisable to use the criteria separately, each being by itself infallible.

Now, that in the sphere of human cognition we have judgements which are necessary, and in the strictest

sense universal, consequently pure a priori, it will be an easy matter to show. If we desire an example from

the sciences, we need only take any proposition in mathematics. If we cast our eyes upon the commonest

operations of the understanding, the proposition, "Every change must have a cause," will amply serve our

purpose. In the latter case, indeed, the conception of a cause so plainly involves the conception of a necessity

of connection with an effect, and of a strict universality of the law, that the very notion of a cause would

entirely disappear, were we to derive it, like Hume, from a frequent association of what happens with that

which precedes; and the habit thence originating of connecting representations the necessity inherent in the

judgement being therefore merely subjective. Besides, without seeking for such examples of principles

existing a priori in cognition, we might easily show that such principles are the indispensable basis of the

possibility of experience itself, and consequently prove their existence a priori. For whence could our

experience itself acquire certainty, if all the rules on which it depends were themselves empirical, and

consequently fortuitous? No one, therefore, can admit the validity of the use of such rules as first principles.

But, for the present, we may content ourselves with having established the fact, that we do possess and

exercise a faculty of pure a priori cognition; and, secondly, with having pointed out the proper tests of such

Not only in judgements, however, but even in conceptions, is an a priori origin manifest. For example, if we

take away by degrees from our conceptions of a body all that can be referred to mere sensuous experience

colour, hardness or softness, weight, even impenetrability the body will then vanish; but the space which it

occupied still remains, and this it is utterly impossible to annihilate in thought. Again, if we take away, in like

manner, from our empirical conception of any object, corporeal or incorporeal, all properties which mere

experience has taught us to connect with it, still we cannot think away those through which we cogitate it as

substance, or adhering to substance, although our conception of substance is more determined than that of an

object. Compelled, therefore, by that necessity with which the conception of substance forces itself upon us,

Of far more importance than all that has been above said, is the consideration that certain of our cognitions

rise completely above the sphere of all possible experience, and by means of conceptions, to which there

exists in the whole extent of experience no corresponding object, seem to extend the range of our judgements

beyond its bounds. And just in this transcendental or supersensible sphere, where experience affords us

neither instruction nor guidance, lie the investigations of reason, which, on account of their importance, we

consider far preferable to, and as having a far more elevated aim than, all that the understanding can achieve

within the sphere of sensuous phenomena. So high a value do we set upon these investigations, that even at

the risk of error, we persist in following them out, and permit neither doubt nor disregard nor indifference to

restrain us from the pursuit. These unavoidable problems of mere pure reason are God, freedom (of will), and

immortality. The science which, with all its preliminaries, has for its especial object the solution of these

problems is named metaphysics a science which is at the very outset dogmatical, that is, it confidently takes

upon itself the execution of this task without any previous investigation of the ability or inability of reason for

Now the safe ground of experience being thus abandoned, it seems nevertheless natural that we should

hesitate to erect a building with the cognitions we possess, without knowing whence they come, and on the

strength of principles, the origin of which is undiscovered. Instead of thus trying to build without a

foundation, it is rather to be expected that we should long ago have put the question, how the understanding

III. Philosophy stands in need of a Science which shall Determine the Possibility, Principles, and Extent of Human Knowledge "a priori" 17

can arrive at these a priori cognitions, and what is the extent, validity, and worth which they may possess?

We say, "This is natural enough," meaning by the word natural, that which is consistent with a just and

reasonable way of thinking; but if we understand by the term, that. which usually happens, nothing indeed

could be more natural and more comprehensible than that this investigation should be left long unattempted.

For one part of our pure knowledge, the science of mathematics, has been long firmly established, and thus

leads us to form flattering expectations with regard to others, though these may be of quite a different nature.

Besides, when we get beyond the bounds of experience, we are of course safe from opposition in that quarter;

and the charm of widening the range of our knowledge is so great that, unless we are brought to a standstill

by some evident contradiction, we hurry on undoubtingly in our course. This, however, may be avoided, if

we are sufficiently cautious in the construction of our fictions, which are not the less fictions on that account.

Mathematical science affords us a brilliant example, how far, independently of all experience, we may carry

our a priori knowledge. It is true that the mathematician occupies himself with objects and cognitions only in

so far as they can be represented by means of intuition. But this circumstance is easily overlooked, because

the said intuition can itself be given a priori, and therefore is hardly to be distinguished from a mere pure

conception. Deceived by such a proof of the power of reason, we can perceive no limits to the extension of

our knowledge. The light dove cleaving in free flight the thin air, whose resistance it feels, might imagine that

her movements would be far more free and rapid in airless space. just in the same way did Plato, abandoning

the world of sense because of the narrow limits it sets to the understanding, venture upon the wings of ideas

beyond it, into the void space of pure intellect. He did not reflect that he made no real progress by all his

efforts; for he met with no resistance which might serve him for a support, as it were, whereon to rest, and on

which he might apply his powers, in order to let the intellect acquire momentum for its progress. It is, indeed,

the common fate of human reason in speculation, to finish the imposing edifice of thought as rapidly as

possible, and then for the first time to begin to examine whether the foundation is a solid one or no. Arrived

at this point, all sorts of excuses are sought after, in order to console us for its want of stability, or rather,

indeed, to enable Us to dispense altogether with so late and dangerous an investigation. But what frees us

during the process of building from all apprehension or suspicion, and flatters us into the belief of its solidity,

is this. A great part, perhaps the greatest part, of the business of our reason consists in the analysation of the

conceptions which we already possess of objects. By this means we gain a multitude of cognitions, which

although really nothing more than elucidations or explanations of that which (though in a confused manner)

was already thought in our conceptions, are, at least in respect of their form, prized as new introspections;

whilst, so far as regards their matter or content, we have really made no addition to our conceptions, but only

disinvolved them. But as this process does furnish a real priori knowledge, which has a sure progress and

useful results, reason, deceived by this, slips in, without being itself aware of it, assertions of a quite different

kind; in which, to given conceptions it adds others, a priori indeed, but entirely foreign to them, without our

knowing how it arrives at these, and, indeed, without such a question ever suggesting itself. I shall therefore

In all judgements wherein the relation of a subject to the predicate is cogitated (I mention affirmative

judgements only here; the application to negative will be very easy), this relation is possible in two different

ways. Either the predicate B belongs to the subject A, as somewhat which is contained (though covertly) in

the conception A; or the predicate B lies completely out of the conception A, although it stands in connection

with it. In the first instance, I term the judgement analytical, in the second, synthetical. Analytical judgements

(affirmative) are therefore those in which the connection of the predicate with the subject is cogitated through

identity; those in which this connection is cogitated without identity, are called synthetical judgements. The

former may be called explicative, the latter augmentative judgements; because the former add in the predicate

nothing to the conception of the subject, but only analyse it into its constituent conceptions, which were

thought already in the subject, although in a confused manner; the latter add to our conceptions of the subject

a predicate which was not contained in it, and which no analysis could ever have discovered therein. For

example, when I say, "All bodies are extended," this is an analytical judgement. For I need not go beyond the

conception of body in order to find extension connected with it, but merely analyse the conception, that is,

become conscious of the manifold properties which I think in that conception, in order to discover this

predicate in it: it is therefore an analytical judgement. On the other hand, when I say, "All bodies are heavy,"

the predicate is something totally different from that which I think in the mere conception of a body. By the

Judgements of experience, as such, are always synthetical. For it would be absurd to think of grounding an

analytical judgement on experience, because in forming such a judgement I need not go out of the sphere of

my conceptions, and therefore recourse to the testimony of experience is quite unnecessary. That "bodies are

extended" is not an empirical judgement, but a proposition which stands firm a priori. For before addressing

myself to experience, I already have in my conception all the requisite conditions for the judgement, and I

have only to extract the predicate from the conception, according to the principle of contradiction, and

thereby at the same time become conscious of the necessity of the judgement, a necessity which I could never

learn from experience. On the other hand, though at first I do not at all include the predicate of weight in my

conception of body in general, that conception still indicates an object of experience, a part of the totality of

experience, to which I can still add other parts; and this I do when I recognize by observation that bodies are

heavy. I can cognize beforehand by analysis the conception of body through the characteristics of extension,

impenetrability, shape, etc., all which are cogitated in this conception. But now I extend my knowledge, and

looking back on experience from which I had derived this conception of body, I find weight at all times

connected with the above characteristics, and therefore I synthetically add to my conceptions this as a

predicate, and say, "All bodies are heavy." Thus it is experience upon which rests the possibility of the

synthesis of the predicate of weight with the conception of body, because both conceptions, although the one

is not contained in the other, still belong to one another (only contingently, however), as parts of a whole,

But to synthetical judgements a priori, such aid is entirely wanting. If I go out of and beyond the conception

A, in order to recognize another B as connected with it, what foundation have I to rest on, whereby to render

the synthesis possible? I have here no longer the advantage of looking out in the sphere of experience for

what I want. Let us take, for example, the proposition, "Everything that happens has a cause." In the

conception of "something that happens," I indeed think an existence which a certain time antecedes, and from

this I can derive analytical judgements. But the conception of a cause lies quite out of the above conception,

and indicates something entirely different from "that which happens," and is consequently not contained in

that conception. How then am I able to assert concerning the general conception "that which happens"

something entirely different from that conception, and to recognize the conception of cause although not

contained in it, yet as belonging to it, and even necessarily? what is here the unknown = X, upon which the

understanding rests when it believes it has found, out of the conception A a foreign predicate B, which it

nevertheless considers to be connected with it? It cannot be experience, because the principle adduced

annexes the two representations, cause and effect, to the representation existence, not only with universality,

which experience cannot give, but also with the expression of necessity, therefore completely a priori and

from pure conceptions. Upon such synthetical, that is augmentative propositions, depends the whole aim of

our speculative knowledge a priori; for although analytical judgements are indeed highly important and

necessary, they are so, only to arrive at that clearness of conceptions which is requisite for a sure and

1. Mathematical judgements are always synthetical. Hitherto this fact, though incontestably true and very

important in its consequences, seems to have escaped the analysts of the human mind, nay, to be in complete

V. In all Theoretical Sciences of Reason, Synthetical Judgements "a priori" are contained as Principles. 19

opposition to all their conjectures. For as it was found that mathematical conclusions all proceed according to

the principle of contradiction (which the nature of every apodeictic certainty requires), people became

persuaded that the fundamental principles of the science also were recognized and admitted in the same way.

But the notion is fallacious; for although a synthetical proposition can certainly be discerned by means of the

principle of contradiction, this is possible only when another synthetical proposition precedes, from which the

Before all, be it observed, that proper mathematical propositions are always judgements a priori, and not

empirical, because they carry along with them the conception of necessity, which cannot be given by

experience. If this be demurred to, it matters not; I will then limit my assertion to pure mathematics, the very

conception of which implies that it consists of knowledge altogether nonempirical and a priori.

We might, indeed at first suppose that the proposition 7 + 5 = 12 is a merely analytical proposition, following

(according to the principle of contradiction) from the conception of a sum of seven and five. But if we regard

it more narrowly, we find that our conception of the sum of seven and five contains nothing more than the

uniting of both sums into one, whereby it cannot at all be cogitated what this single number is which

embraces both. The conception of twelve is by no means obtained by merely cogitating the union of seven

and five; and we may analyse our conception of such a possible sum as long as we will, still we shall never

discover in it the notion of twelve. We must go beyond these conceptions, and have recourse to an intuition

which corresponds to one of the two our five fingers, for example, or like Segner in his Arithmetic five

points, and so by degrees, add the units contained in the five given in the intuition, to the conception of seven.

For I first take the number 7, and, for the conception of 5 calling in the aid of the fingers of my hand as

objects of intuition, I add the units, which I before took together to make up the number 5, gradually now by

means of the material image my hand, to the number 7, and by this process, I at length see the number 12

arise. That 7 should be added to 5, I have certainly cogitated in my conception of a sum = 7 + 5, but not that

this sum was equal to 12. Arithmetical propositions are therefore always synthetical, of which we may

become more clearly convinced by trying large numbers. For it will thus become quite evident that, turn and

twist our conceptions as we may, it is impossible, without having recourse to intuition, to arrive at the sum

total or product by means of the mere analysis of our conceptions. just as little is any principle of pure

geometry analytical. "A straight line between two points is the shortest," is a synthetical proposition. For my

conception of straight contains no notion of quantity, but is merely qualitative. The conception of the shortest

is therefore fore wholly an addition, and by no analysis can it be extracted from our conception of a straight

line. Intuition must therefore here lend its aid, by means of which, and thus only, our synthesis is possible.

Some few principles preposited by geometricians are, indeed, really analytical, and depend on the principle of

contradiction. They serve, however, like identical propositions, as links in the chain of method, not as

principles for example, a = a, the whole is equal to itself, or (a+b) > a, the whole is greater than its part. And

yet even these principles themselves, though they derive their validity from pure conceptions, are only

admitted in mathematics because they can be presented in intuition. What causes us here commonly to

believe that the predicate of such apodeictic judgements is already contained in our conception, and that the

judgement is therefore analytical, is merely the equivocal nature of the expression. We must join in thought a

certain predicate to a given conception, and this necessity cleaves already to the conception. But the question

is, not what we must join in thought to the given conception, but what we really think therein, though only

obscurely, and then it becomes manifest that the predicate pertains to these conceptions, necessarily indeed,

yet not as thought in the conception itself, but by virtue of an intuition, which must be added to the

2. The science of natural philosophy (physics) contains in itself synthetical judgements a priori, as principles.

I shall adduce two propositions. For instance, the proposition, "In all changes of the material world, the

quantity of matter remains unchanged"; or, that, "In all communication of motion, action and reaction must

always be equal." In both of these, not only is the necessity, and therefore their origin a priori clear, but also

V. In all Theoretical Sciences of Reason, Synthetical Judgements "a priori" are contained as Principles. 20

that they are synthetical propositions. For in the conception of matter, I do not cogitate its permanency, but

merely its presence in space, which it fills. I therefore really go out of and beyond the conception of matter, in

order to think on to it something a priori, which I did not think in it. The proposition is therefore not

analytical, but synthetical, and nevertheless conceived a priori; and so it is with regard to the other

3. As to metaphysics, even if we look upon it merely as an attempted science, yet, from the nature of human

reason, an indispensable one, we find that it must contain synthetical propositions a priori. It is not merely the

duty of metaphysics to dissect, and thereby analytically to illustrate the conceptions which we form a priori of

things; but we seek to widen the range of our a priori knowledge. For this purpose, we must avail ourselves of

such principles as add something to the original conception something not identical with, nor contained in it,

and by means of synthetical judgements a priori, leave far behind us the limits of experience; for example, in

the proposition, "the world must have a beginning," and such like. Thus metaphysics, according to the proper

It is extremely advantageous to be able to bring a number of investigations under the formula of a single

problem. For in this manner, we not only facilitate our own labour, inasmuch as we define it clearly to

ourselves, but also render it more easy for others to decide whether we have done justice to our undertaking.

The proper problem of pure reason, then, is contained in the question: "How are synthetical judgements a

That metaphysical science has hitherto remained in so vacillating a state of uncertainty and contradiction, is

only to be attributed to the fact that this great problem, and perhaps even the difference between analytical

and synthetical judgements, did not sooner suggest itself to philosophers. Upon the solution of this problem,

or upon sufficient proof of the impossibility of synthetical knowledge a priori, depends the existence or

downfall of the science of metaphysics. Among philosophers, David Hume came the nearest of all to this

problem; yet it never acquired in his mind sufficient precision, nor did he regard the question in its

universality. On the contrary, he stopped short at the synthetical proposition of the connection of an effect

with its cause (principium causalitatis), insisting that such proposition a priori was impossible. According to

his conclusions, then, all that we term metaphysical science is a mere delusion, arising from the fancied

insight of reason into that which is in truth borrowed from experience, and to which habit has given the

appearance of necessity. Against this assertion, destructive to all pure philosophy, he would have been

guarded, had he had our problem before his eyes in its universality. For he would then have perceived that,

according to his own argument, there likewise could not be any pure mathematical science, which assuredly

cannot exist without synthetical propositions a priori an absurdity from which his good understanding must

In the solution of the above problem is at the same time comprehended the possibility of the use of pure

reason in the foundation and construction of all sciences which contain theoretical knowledge a priori of

Respecting these sciences, as they do certainly exist, it may with propriety be asked, how they are possible?

for that they must be possible is shown by the fact of their really existing.* But as to metaphysics, the

miserable progress it has hitherto made, and the fact that of no one system yet brought forward, far as regards

its true aim, can it be said that this science really exists, leaves any one at liberty to doubt with reason the

*As to the existence of pure natural science, or physics, perhaps many may still express doubts. But we have

only to look at the different propositions which are commonly treated of at the commencement of proper

(empirical) physical science those, for example, relating to the permanence of the same quantity of matter,

the vis inertiae, the equality of action and reaction, etc. to be soon convinced that they form a science of

pure physics (physica pura, or rationalis), which well deserves to be separately exposed as a special science,

Yet, in a certain sense, this kind of knowledge must unquestionably be looked upon as given; in other words,

metaphysics must be considered as really existing, if not as a science, nevertheless as a natural disposition of

the human mind (metaphysica naturalis). For human reason, without any instigations imputable to the mere

vanity of great knowledge, unceasingly progresses, urged on by its own feeling of need, towards such

questions as cannot be answered by any empirical application of reason, or principles derived therefrom; and

so there has ever really existed in every man some system of metaphysics. It will always exist, so soon as

reason awakes to the exercise of its power of speculation. And now the question arises: "How is metaphysics,

as a natural disposition, possible?" In other words, how, from the nature of universal human reason, do those

questions arise which pure reason proposes to itself, and which it is impelled by its own feeling of need to

But as in all the attempts hitherto made to answer the questions which reason is prompted by its very nature

to propose to itself, for example, whether the world had a beginning, or has existed from eternity, it has

always met with unavoidable contradictions, we must not rest satisfied with the mere natural disposition of

the mind to metaphysics, that is, with the existence of the faculty of pure reason, whence, indeed, some sort

of metaphysical system always arises; but it must be possible to arrive at certainty in regard to the question

whether we know or do not know the things of which metaphysics treats. We must be able to arrive at a

decision on the subjects of its questions, or on the ability or inability of reason to form any judgement

respecting them; and therefore either to extend with confidence the bounds of our pure reason, or to set

strictly defined and safe limits to its action. This last question, which arises out of the above universal

Thus, the critique of reason leads at last, naturally and necessarily, to science; and, on the other hand, the

dogmatical use of reason without criticism leads to groundless assertions, against which others equally

Besides, this science cannot be of great and formidable prolixity, because it has not to do with objects of

reason, the variety of which is inexhaustible, but merely with Reason herself and her problems; problems

which arise out of her own bosom, and are not proposed to her by the nature of outward things, but by her

own nature. And when once Reason has previously become able completely to understand her own power in

regard to objects which she meets with in experience, it will be easy to determine securely the extent and

limits of her attempted application to objects beyond the confines of experience.

We may and must, therefore, regard the attempts hitherto made to establish metaphysical science

dogmatically as nonexistent. For what of analysis, that is, mere dissection of conceptions, is contained in

one or other, is not the aim of, but only a preparation for metaphysics proper, which has for its object the

extension, by means of synthesis, of our a priori knowledge. And for this purpose, mere analysis is of course

useless, because it only shows what is contained in these conceptions, but not how we arrive, a priori, at

them; and this it is her duty to show, in order to be able afterwards to determine their valid use in regard to all

objects of experience, to all knowledge in general. But little selfdenial, indeed, is needed to give up these

pretensions, seeing the undeniable, and in the dogmatic mode of procedure, inevitable contradictions of

Reason with herself, have long since ruined the reputation of every system of metaphysics that has appeared

up to this time. It will require more firmness to remain undeterred by difficulty from within, and opposition

from without, from endeavouring, by a method quite opposed to all those hitherto followed, to further the

growth and fruitfulness of a science indispensable to human reason a science from which every branch it

From all that has been said, there results the idea of a particular science, which may be called the Critique of

Pure Reason. For reason is the faculty which furnishes us with the principles of knowledge a priori. Hence,

pure reason is the faculty which contains the principles of cognizing anything absolutely a priori. An organon

of pure reason would be a compendium of those principles according to which alone all pure cognitions a

priori can be obtained. The completely extended application of such an organon would afford us a system of

pure reason. As this, however, is demanding a great deal, and it is yet doubtful whether any extension of our

knowledge be here possible, or, if so, in what cases; we can regard a science of the mere criticism of pure

reason, its sources and limits, as the propaedeutic to a system of pure reason. Such a science must not be

called a doctrine, but only a critique of pure reason; and its use, in regard to speculation, would be only

negative, not to enlarge the bounds of, but to purify, our reason, and to shield it against error which alone is

no little gain. I apply the term transcendental to all knowledge which is not so much occupied with objects as

with the mode of our cognition of these objects, so far as this mode of cognition is possible a priori. A system

of such conceptions would be called transcendental philosophy. But this, again, is still beyond the bounds of

our present essay. For as such a science must contain a complete exposition not only of our synthetical a

priori, but of our analytical a priori knowledge, it is of too wide a range for our present purpose, because we

do not require to carry our analysis any farther than is necessary to understand, in their full extent, the

principles of synthesis a priori, with which alone we have to do. This investigation, which we cannot properly

call a doctrine, but only a transcendental critique, because it aims not at the enlargement, but at the correction

and guidance, of our knowledge, and is to serve as a touchstone of the worth or worthlessness of all

knowledge a priori, is the sole object of our present essay. Such a critique is consequently, as far as possible,

a preparation for an organon; and if this new organon should be found to fail, at least for a canon of pure

reason, according to which the complete system of the philosophy of pure reason, whether it extend or limit

the bounds of that reason, might one day be set forth both analytically and synthetically. For that this is

possible, nay, that such a system is not of so great extent as to preclude the hope of its ever being completed,

is evident. For we have not here to do with the nature of outward objects, which is infinite, but solely with the

mind, which judges of the nature of objects, and, again, with the mind only in respect of its cognition a priori.

And the object of our investigations, as it is not to be sought without, but, altogether within, ourselves, cannot

remain concealed, and in all probability is limited enough to be completely surveyed and fairly estimated,

according to its worth or worthlessness. Still less let the reader here expect a critique of books and systems of

pure reason; our present object is exclusively a critique of the faculty of pure reason itself. Only when we

make this critique our foundation, do we possess a pure touchstone for estimating the philosophical value of

ancient and modern writings on this subject; and without this criterion, the incompetent historian or judge

decides upon and corrects the groundless assertions of others with his own, which have themselves just as

Transcendental philosophy is the idea of a science, for which the Critique of Pure Reason must sketch the

whole plan architectonically, that is, from principles, with a full guarantee for the validity and stability of all

the parts which enter into the building. It is the system of all the principles of pure reason. If this Critique

itself does not assume the title of transcendental philosophy, it is only because, to be a complete system, it

ought to contain a full analysis of all human knowledge a priori. Our critique must, indeed, lay before us a

complete enumeration of all the radical conceptions which constitute the said pure knowledge. But from the

complete analysis of these conceptions themselves, as also from a complete investigation of those derived

from them, it abstains with reason; partly because it would be deviating from the end in view to occupy itself

with this analysis, since this process is not attended with the difficulty and insecurity to be found in the

VII. Idea and Division of a Particular Science, under the Name of a Critique of Pure Reason. 23

synthesis, to which our critique is entirely devoted, and partly because it would be inconsistent with the unity

of our plan to burden this essay with the vindication of the completeness of such an analysis and deduction,

with which, after all, we have at present nothing to do. This completeness of the analysis of these radical

conceptions, as well as of the deduction from the conceptions a priori which may be given by the analysis, we

can, however, easily attain, provided only that we are in possession of all these radical conceptions, which are

to serve as principles of the synthesis, and that in respect of this main purpose nothing is wanting.

To the Critique of Pure Reason, therefore, belongs all that constitutes transcendental philosophy; and it is the

complete idea of transcendental philosophy, but still not the science itself; because it only proceeds so far

with the analysis as is necessary to the power of judging completely of our synthetical knowledge a priori.

The principal thing we must attend to, in the division of the parts of a science like this, is that no conceptions

must enter it which contain aught empirical; in other words, that the knowledge a priori must be completely

pure. Hence, although the highest principles and fundamental conceptions of morality are certainly cognitions

a priori, yet they do not belong to transcendental philosophy; because, though they certainly do not lay the

conceptions of pain, pleasure, desires, inclinations, etc. (which are all of empirical origin), at the foundation

of its precepts, yet still into the conception of duty as an obstacle to be overcome, or as an incitement which

should not be made into a motive these empirical conceptions must necessarily enter, in the construction of

a system of pure morality. Transcendental philosophy is consequently a philosophy of the pure and merely

speculative reason. For all that is practical, so far as it contains motives, relates to feelings, and these belong

If we wish to divide this science from the universal point of view of a science in general, it ought to

comprehend, first, a Doctrine of the Elements, and, secondly, a Doctrine of the Method of pure reason. Each

of these main divisions will have its subdivisions, the separate reasons for which we cannot here

particularize. Only so much seems necessary, by way of introduction of premonition, that there are two

sources of human knowledge (which probably spring from a common, but to us unknown root), namely,

sense and understanding. By the former, objects are given to us; by the latter, thought. So far as the faculty of

sense may contain representations a priori, which form the conditions under which objects are given, in so far

it belongs to transcendental philosophy. The transcendental doctrine of sense must form the first part of our

science of elements, because the conditions under which alone the objects of human knowledge are given

In whatsoever mode, or by whatsoever means, our knowledge may relate to objects, it is at least quite clear

that the only manner in which it immediately relates to them is by means of an intuition. To this as the

indispensable groundwork, all thought points. But an intuition can take place only in so far as the object is

given to us. This, again, is only possible, to man at least, on condition that the object affect the mind in a

certain manner. The capacity for receiving representations (receptivity) through the mode in which we are

affected by objects, objects, is called sensibility. By means of sensibility, therefore, objects are given to us,

and it alone furnishes us with intuitions; by the understanding they are thought, and from it arise conceptions.

But an thought must directly, or indirectly, by means of certain signs, relate ultimately to intuitions;

consequently, with us, to sensibility, because in no other way can an object be given to us.

The effect of an object upon the faculty of representation, so far as we are affected by the said object, is

sensation. That sort of intuition which relates to an object by means of sensation is called an empirical

intuition. The undetermined object of an empirical intuition is called phenomenon. That which in the

phenomenon corresponds to the sensation, I term its matter; but that which effects that the content of the

phenomenon can be arranged under certain relations, I call its form. But that in which our sensations are

merely arranged, and by which they are susceptible of assuming a certain form, cannot be itself sensation. It

is, then, the matter of all phenomena that is given to us a posteriori; the form must lie ready a priori for them

I call all representations pure, in the transcendental meaning of the word, wherein nothing is met with that

belongs to sensation. And accordingly we find existing in the mind a priori, the pure form of sensuous

intuitions in general, in which all the manifold content of the phenomenal world is arranged and viewed

under certain relations. This pure form of sensibility I shall call pure intuition. Thus, if I take away from our

representation of a body all that the understanding thinks as belonging to it, as substance, force, divisibility,

etc., and also whatever belongs to sensation, as impenetrability, hardness, colour, etc.; yet there is still

something left us from this empirical intuition, namely, extension and shape. These belong to pure intuition,

which exists a priori in the mind, as a mere form of sensibility, and without any real object of the senses or

The science of all the principles of sensibility a priori, I call transcendental aesthetic.* There must, then, be

such a science forming the first part of the transcendental doctrine of elements, in contradistinction to that

part which contains the principles of pure thought, and which is called transcendental logic.

*The Germans are the only people who at present use this word to indicate what others call the critique of

taste. At the foundation of this term lies the disappointed hope, which the eminent analyst, Baumgarten,

conceived, of subjecting the criticism of the beautiful to principles of reason, and so of elevating its rules into

a science. But his endeavours were vain. For the said rules or criteria are, in respect to their chief sources,

merely empirical, consequently never can serve as determinate laws a priori, by which our judgement in

matters of taste is to be directed. It is rather our judgement which forms the proper test as to the correctness

of the principles. On this account it is advisable to give up the use of the term as designating the critique of

taste, and to apply it solely to that doctrine, which is true science the science of the laws of sensibility and

thus come nearer to the language and the sense of the ancients in their wellknown division of the objects of

cognition into aiotheta kai noeta, or to share it with speculative philosophy, and employ it partly in a

In the science of transcendental aesthetic accordingly, we shall first isolate sensibility or the sensuous faculty,

by separating from it all that is annexed to its perceptions by the conceptions of understanding, so that

nothing be left but empirical intuition. In the next place we shall take away from this intuition all that belongs

to sensation, so that nothing may remain but pure intuition, and the mere form of phenomena, which is all

that the sensibility can afford a priori. From this investigation it will be found that there are two pure forms of

sensuous intuition, as principles of knowledge a priori, namely, space and time. To the consideration of these

By means of the external sense (a property of the mind), we represent to ourselves objects as without us, and

these all in space. Herein alone are their shape, dimensions, and relations to each other determined or

determinable. The internal sense, by means of which the mind contemplates itself or its internal state, gives,

indeed, no intuition of the soul as an object; yet there is nevertheless a determinate form, under which alone

the contemplation of our internal state is possible, so that all which relates to the inward determinations of the

mind is represented in relations of time. Of time we cannot have any external intuition, any more than we can

have an internal intuition of space. What then are time and space? Are they real existences? Or, are they

merely relations or determinations of things, such, however, as would equally belong to these things in

themselves, though they should never become objects of intuition; or, are they such as belong only to the

form of intuition, and consequently to the subjective constitution of the mind, without which these predicates

of time and space could not be attached to any object? In order to become informed on these points, we shall

first give an exposition of the conception of space. By exposition, I mean the clear, though not detailed,

representation of that which belongs to a conception; and an exposition is metaphysical when it contains that

1. Space is not a conception which has been derived from outward experiences. For, in order that certain

sensations may relate to something without me (that is, to something which occupies a different part of space

from that in which I am); in like manner, in order that I may represent them not merely as without, of, and

near to each other, but also in separate places, the representation of space must already exist as a foundation.

Consequently, the representation of space cannot be borrowed from the relations of external phenomena

through experience; but, on the contrary, this external experience is itself only possible through the said

2. Space then is a necessary representation a priori, which serves for the foundation of all external intuitions.

We never can imagine or make a representation to ourselves of the nonexistence of space, though we may

easily enough think that no objects are found in it. It must, therefore, be considered as the condition of the

possibility of phenomena, and by no means as a determination dependent on them, and is a representation a

3. Space is no discursive, or as we say, general conception of the relations of things, but a pure intuition. For,

in the first place, we can only represent to ourselves one space, and, when we talk of divers spaces, we mean

only parts of one and the same space. Moreover, these parts cannot antecede this one allembracing space, as

the component parts from which the aggregate can be made up, but can be cogitated only as existing in it.

Space is essentially one, and multiplicity in it, consequently the general notion of spaces, of this or that space,

depends solely upon limitations. Hence it follows that an a priori intuition (which is not empirical) lies at the

root of all our conceptions of space. Thus, moreover, the principles of geometry for example, that "in a

triangle, two sides together are greater than the third," are never deduced from general conceptions of line

4. Space is represented as an infinite given quantity. Now every conception must indeed be considered as a

representation which is contained in an infinite multitude of different possible representations, which,

therefore, comprises these under itself; but no conception, as such, can be so conceived, as if it contained

within itself an infinite multitude of representations. Nevertheless, space is so conceived of, for all parts of

space are equally capable of being produced to infinity. Consequently, the original representation of space is

By a transcendental exposition, I mean the explanation of a conception, as a principle, whence can be

discerned the possibility of other synthetical a priori cognitions. For this purpose, it is requisite, firstly, that

such cognitions do really flow from the given conception; and, secondly, that the said cognitions are only

possible under the presupposition of a given mode of explaining this conception.

Geometry is a science which determines the properties of space synthetically, and yet a priori. What, then,

must be our representation of space, in order that such a cognition of it may be possible? It must be originally

intuition, for from a mere conception, no propositions can be deduced which go out beyond the conception,

and yet this happens in geometry. (Introd. V.) But this intuition must be found in the mind a priori, that is,

before any perception of objects, consequently must be pure, not empirical, intuition. For geometrical

principles are always apodeictic, that is, united with the consciousness of their necessity, as: "Space has only

three dimensions." But propositions of this kind cannot be empirical judgements, nor conclusions from them.

(Introd. II.) Now, how can an external intuition anterior to objects themselves, and in which our conception of

objects can be determined a priori, exist in the human mind? Obviously not otherwise than in so far as it has

its seat in the subject only, as the formal capacity of the subject's being affected by objects, and thereby of

obtaining immediate representation, that is, intuition; consequently, only as the form of the external sense in

Thus it is only by means of our explanation that the possibility of geometry, as a synthetical science a priori,

becomes comprehensible. Every mode of explanation which does not show us this possibility, although in

appearance it may be similar to ours, can with the utmost certainty be distinguished from it by these marks.

(a) Space does Space does not represent any property of objects as things in themselves, nor does it represent

them in their relations to each other; in other words, space does not represent to us any determination of

objects such as attaches to the objects themselves, and would remain, even though all subjective conditions of

the intuition were abstracted. For neither absolute nor relative determinations of objects can be intuited prior

to the existence of the things to which they belong, and therefore not a priori.

(b) Space is nothing else than the form of all phenomena of the external sense, that is, the subjective

condition of the sensibility, under which alone external intuition is possible. Now, because the receptivity or

capacity of the subject to be affected by objects necessarily antecedes all intuitions of these objects, it is

easily understood how the form of all phenomena can be given in the mind previous to all actual perceptions,

therefore a priori, and how it, as a pure intuition, in which all objects must be determined, can contain

It is therefore from the human point of view only that we can speak of space, extended objects, etc. If we

depart from the subjective condition, under which alone we can obtain external intuition, or, in other words,

by means of which we are affected by objects, the representation of space has no meaning whatsoever. This

predicate is only applicable to things in so far as they appear to us, that is, are objects of sensibility. The

constant form of this receptivity, which we call sensibility, is a necessary condition of all relations in which

objects can be intuited as existing without us, and when abstraction of these objects is made, is a pure

intuition, to which we give the name of space. It is clear that we cannot make the special conditions of

sensibility into conditions of the possibility of things, but only of the possibility of their existence as far as

they are phenomena. And so we may correctly say that space contains all which can appear to us externally,

but not all things considered as things in themselves, be they intuited or not, or by whatsoever subject one

will. As to the intuitions of other thinking beings, we cannot judge whether they are or are not bound by the

same conditions which limit our own intuition, and which for us are universally valid. If we join the

limitation of a judgement to the conception of the subject, then the judgement will possess unconditioned

validity. For example, the proposition, "All objects are beside each other in space," is valid only under the

limitation that these things are taken as objects of our sensuous intuition. But if I join the condition to the

conception and say, "All things, as external phenomena, are beside each other in space," then the rule is valid

universally, and without any limitation. Our expositions, consequently, teach the reality (i.e., the objective

validity) of space in regard of all which can be presented to us externally as object, and at the same time also

the ideality of space in regard to objects when they are considered by means of reason as things in

themselves, that is, without reference to the constitution of our sensibility. We maintain, therefore, the

empirical reality of space in regard to all possible external experience, although we must admit its

transcendental ideality; in other words, that it is nothing, so soon as we withdraw the condition upon which

the possibility of all experience depends and look upon space as something that belongs to things in

But, with the exception of space, there is no representation, subjective and ref erring to something external to

us, which could be called objective a priori. For there are no other subjective representations from which we

can deduce synthetical propositions a priori, as we can from the intuition of space. (See SS 3.) Therefore, to

speak accurately, no ideality whatever belongs to these, although they agree in this respect with the

representation of space, that they belong merely to the subjective nature of the mode of sensuous perception;

such a mode, for example, as that of sight, of hearing, and of feeling, by means of the sensations of colour,

sound, and heat, but which, because they are only sensations and not intuitions, do not of themselves give us

the cognition of any object, least of all, an a priori cognition. My purpose, in the above remark, is merely this:

to guard any one against illustrating the asserted ideality of space by examples quite insufficient, for example,

by colour, taste, etc.; for these must be contemplated not as properties of things, but only as changes in the

subject, changes which may be different in different men. For, in such a case, that which is originally a mere

phenomenon, a rose, for example, is taken by the empirical understanding for a thing in itself, though to

every different eye, in respect of its colour, it may appear different. On the contrary, the transcendental

conception of phenomena in space is a critical admonition, that, in general, nothing which is intuited in space

is a thing in itself, and that space is not a form which belongs as a property to things; but that objects are quite

unknown to us in themselves, and what we call outward objects, are nothing else but mere representations of

our sensibility, whose form is space, but whose real correlate, the thing in itself, is not known by means of

these representations, nor ever can be, but respecting which, in experience, no inquiry is ever made.

1. Time is not an empirical conception. For neither coexistence nor succession would be perceived by us, if

the representation of time did not exist as a foundation a priori. Without this presupposition we could not

represent to ourselves that things exist together at one and the same time, or at different times, that is,

2. Time is a necessary representation, lying at the foundation of all our intuitions. With regard to phenomena

in general, we cannot think away time from them, and represent them to ourselves as out of and unconnected

with time, but we can quite well represent to ourselves time void of phenomena. Time is therefore given a

priori. In it alone is all reality of phenomena possible. These may all be annihilated in thought, but time itself,

3. On this necessity a priori is also founded the possibility of apodeictic principles of the relations of time, or

axioms of time in general, such as: "Time has only one dimension," "Different times are not coexistent but

successive" (as different spaces are not successive but coexistent). These principles cannot be derived from

experience, for it would give neither strict universality, nor apodeictic certainty. We should only be able to

say, "so common experience teaches us," but not "it must be so." They are valid as rules, through which, in

general, experience is possible; and they instruct us respecting experience, and not by means of it.

4. Time is not a discursive, or as it is called, general conception, but a pure form of the sensuous intuition.

Different times are merely parts of one and the same time. But the representation which can only be given by

a single object is an intuition. Besides, the proposition that different times cannot be coexistent could not be

derived from a general conception. For this proposition is synthetical, and therefore cannot spring out of

conceptions alone. It is therefore contained immediately in the intuition and representation of time.

5. The infinity of time signifies nothing more than that every determined quantity of time is possible only

through limitations of one time lying at the foundation. Consequently, the original representation, time, must

be given as unlimited. But as the determinate representation of the parts of time and of every quantity of an

object can only be obtained by limitation, the complete representation of time must not be furnished by

means of conceptions, for these contain only partial representations. Conceptions, on the contrary, must have

I may here refer to what is said above (SS 5, 3), where, for or sake of brevity, I have placed under the head of

metaphysical exposition, that which is properly transcendental. Here I shall add that the conception of

change, and with it the conception of motion, as change of place, is possible only through and in the

representation of time; that if this representation were not an intuition (internal) a priori, no conception, of

whatever kind, could render comprehensible the possibility of change, in other words, of a conjunction of

contradictorily opposed predicates in one and the same object, for example, the presence of a thing in a place

and the nonpresence of the same thing in the same place. It is only in time that it is possible to meet with

two contradictorily opposed determinations in one thing, that is, after each other. thus our conception of time

explains the possibility of so much synthetical knowledge a priori, as is exhibited in the general doctrine of

(a) Time is not something which subsists of itself, or which inheres in things as an objective determination,

and therefore remains, when abstraction is made of the subjective conditions of the intuition of things. For in

the former case, it would be something real, yet without presenting to any power of perception any real

object. In the latter case, as an order or determination inherent in things themselves, it could not be antecedent

to things, as their condition, nor discerned or intuited by means of synthetical propositions a priori. But all

this is quite possible when we regard time as merely the subjective condition under which all our intuitions

take place. For in that case, this form of the inward intuition can be represented prior to the objects, and

(b) Time is nothing else than the form of the internal sense, that is, of the intuitions of self and of our internal

state. For time cannot be any determination of outward phenomena. It has to do neither with shape nor

position; on the contrary, it determines the relation of representations in our internal state. And precisely

because this internal intuition presents to us no shape or form, we endeavour to supply this want by analogies,

and represent the course of time by a line progressing to infinity, the content of which constitutes a series

which is only of one dimension; and we conclude from the properties of this line as to all the properties of

time, with this single exception, that the parts of the line are coexistent, whilst those of time are successive.

From this it is clear also that the representation of time is itself an intuition, because all its relations can be

intuition, is limited as a condition a priori to external phenomena alone. On the other hand, because all

representations, whether they have or have not external things for their objects, still in themselves, as

determinations of the mind, belong to our internal state; and because this internal state is subject to the formal

condition of the internal intuition, that is, to time time is a condition a priori of all phenomena whatsoever

the immediate condition of all internal, and thereby the mediate condition of all external phenomena. If I can

say a priori, "All outward phenomena are in space, and determined a priori according to the relations of

space," I can also, from the principle of the internal sense, affirm universally, "All phenomena in general, that

is, all objects of the senses, are in time and stand necessarily in relations of time."

If we abstract our internal intuition of ourselves and all external intuitions, possible only by virtue of this

internal intuition and presented to us by our faculty of representation, and consequently take objects as they

are in themselves, then time is nothing. It is only of objective validity in regard to phenomena, because these

are things which we regard as objects of our senses. It no longer objective we, make abstraction of the

sensuousness of our intuition, in other words, of that mode of representation which is peculiar to us, and

speak of things in general. Time is therefore merely a subjective condition of our (human) intuition (which is

always sensuous, that is, so far as we are affected by objects), and in itself, independently of the mind or

subject, is nothing. Nevertheless, in respect of all phenomena, consequently of all things which come within

the sphere of our experience, it is necessarily objective. We cannot say, "All things are in time," because in

this conception of things in general, we abstract and make no mention of any sort of intuition of things. But

this is the proper condition under which time belongs to our representation of objects. If we add the condition

to the conception, and say, "All things, as phenomena, that is, objects of sensuous intuition, are in time," then

What we have now set forth teaches, therefore, the empirical reality of time; that is, its objective validity in

reference to all objects which can ever be presented to our senses. And as our intuition is always sensuous, no

object ever can be presented to us in experience, which does not come under the conditions of time. On the

other hand, we deny to time all claim to absolute reality; that is, we deny that it, without having regard to the

form of our sensuous intuition, absolutely inheres in things as a condition or property. Such properties as

belong to objects as things in themselves never can be presented to us through the medium of the senses.

Herein consists, therefore, the transcendental ideality of time, according to which, if we abstract the

subjective conditions of sensuous intuition, it is nothing, and cannot be reckoned as subsisting or inhering in

objects as things in themselves, independently of its relation to our intuition. this ideality, like that of space, is

not to be proved or illustrated by fallacious analogies with sensations, for this reason that in such arguments

or illustrations, we make the presupposition that the phenomenon, in which such and such predicates inhere,

has objective reality, while in this case we can only find such an objective reality as is itself empirical, that is,

regards the object as a mere phenomenon. In reference to this subject, see the remark in Section I (SS 4)

Against this theory, which grants empirical reality to time, but denies to it absolute and transcendental reality,

I have heard from intelligent men an objection so unanimously urged that I conclude that it must naturally

present itself to every reader to whom these considerations are novel. It runs thus: "Changes are real" (this the

continual change in our own representations demonstrates, even though the existence of all external

phenomena, together with their changes, is denied). Now, changes are only possible in time, and therefore

time must be something real. But there is no difficulty in answering this. I grant the whole argument. Time,

no doubt, is something real, that is, it is the real form of our internal intuition. It therefore has subjective

reality, in reference to our internal experience, that is, I have really the representation of time and of my

determinations therein. Time, therefore, is not to be regarded as an object, but as the mode of representation

of myself as an object. But if I could intuite myself, or be intuited by another being, without this condition of

sensibility, then those very determinations which we now represent to ourselves as changes, would present to

us a knowledge in which the representation of time, and consequently of change, would not appear. The

empirical reality of time, therefore, remains, as the condition of all our experience. But absolute reality,

according to what has been said above, cannot be granted it. Time is nothing but the form of our internal

intuition.* If we take away from it the special condition of our sensibility, the conception of time also

vanishes; and it inheres not in the objects themselves, but solely in the subject (or mind) which intuites them.

*I can indeed say "my representations follow one another, or are successive"; but this means only that we are

conscious of them as in a succession, that is, according to the form of the internal sense. Time, therefore, is

not a thing in itself, nor is it any objective determination pertaining to, or inherent in things.

But the reason why this objection is so unanimously brought against our doctrine of time, and that too by

disputants who cannot start any intelligible arguments against the doctrine of the ideality of space, is this

they have no hope of demonstrating apodeictically the absolute reality of space, because the doctrine of

idealism is against them, according to which the reality of external objects is not capable of any strict proof.

On the other hand, the reality of the object of our internal sense (that is, myself and my internal state) is clear

immediately through consciousness. The former external objects in space might be a mere delusion, but

the latter the object of my internal perception is undeniably real. They do not, however, reflect that both,

without question of their reality as representations, belong only to the genus phenomenon, which has always

two aspects, the one, the object considered as a thing in itself, without regard to the mode of intuiting it, and

the nature of which remains for this very reason problematical, the other, the form of our intuition of the

object, which must be sought not in the object as a thing in itself, but in the subject to which it appears

which form of intuition nevertheless belongs really and necessarily to the phenomenal object.

Time and space are, therefore, two sources of knowledge, from which, a priori, various synthetical cognitions

can be drawn. Of this we find a striking example in the cognitions of space and its relations, which form the

foundation of pure mathematics. They are the two pure forms of all intuitions, and thereby make synthetical

propositions a priori possible. But these sources of knowledge being merely conditions of our sensibility, do

therefore, and as such, strictly determine their own range and purpose, in that they do not and cannot present

objects as things in themselves, but are applicable to them solely in so far as they are considered as sensuous

phenomena. The sphere of phenomena is the only sphere of their validity, and if we venture out of this, no

further objective use can be made of them. For the rest, this formal reality of time and space leaves the

validity of our empirical knowledge unshaken; for our certainty in that respect is equally firm, whether these

forms necessarily inhere in the things themselves, or only in our intuitions of them. On the other hand, those

who maintain the absolute reality of time and space, whether as essentially subsisting, or only inhering, as

modifications, in things, must find themselves at utter variance with the principles of experience itself. For, if

they decide for the first view, and make space and time into substances, this being the side taken by

mathematical natural philosophers, they must admit two selfsubsisting nonentities, infinite and eternal,

which exist (yet without there being anything real) for the purpose of containing in themselves everything

that is real. If they adopt the second view of inherence, which is preferred by some metaphysical natural

philosophers, and regard space and time as relations (contiguity in space or succession in time), abstracted

from experience, though represented confusedly in this state of separation, they find themselves in that case

necessitated to deny the validity of mathematical doctrines a priori in reference to real things (for example, in

space) at all events their apodeictic certainty. For such certainty cannot be found in an a posteriori

proposition; and the conceptions a priori of space and time are, according to this opinion, mere creations of

the imagination, having their source really in experience, inasmuch as, out of relations abstracted from

experience, imagination has made up something which contains, indeed, general statements of these relations,

yet of which no application can be made without the restrictions attached thereto by nature. The former of

these parties gains this advantage, that they keep the sphere of phenomena free for mathematical science. On

the other hand, these very conditions (space and time) embarrass them greatly, when the understanding

endeavours to pass the limits of that sphere. The latter has, indeed, this advantage, that the representations of

space and time do not come in their way when they wish to judge of objects, not as phenomena, but merely in

their relation to the understanding. Devoid, however, of a true and objectively valid a priori intuition, they

can neither furnish any basis for the possibility of mathematical cognitions a priori, nor bring the propositions

of experience into necessary accordance with those of mathematics. In our theory of the true nature of these

In conclusion, that transcendental aesthetic cannot contain any more than these two elements space and

time, is sufficiently obvious from the fact that all other conceptions appertaining to sensibility, even that of

motion, which unites in itself both elements, presuppose something empirical. Motion, for example,

presupposes the perception of something movable. But space considered in itself contains nothing movable,

consequently motion must be something which is found in space only through experience in other words, an

empirical datum. In like manner, transcendental aesthetic cannot number the conception of change among its

data a priori; for time itself does not change, but only something which is in time. To acquire the conception

of change, therefore, the perception of some existing object and of the succession of its determinations, in one

I. In order to prevent any misunderstanding, it will be requisite, in the first place, to recapitulate, as clearly as

possible, what our opinion is with respect to the fundamental nature of our sensuous cognition in general. We

have intended, then, to say that all our intuition is nothing but the representation of phenomena; that the

things which we intuite, are not in themselves the same as our representations of them in intuition, nor are

their relations in themselves so constituted as they appear to us; and that if we take away the subject, or even

only the subjective constitution of our senses in general, then not only the nature and relations of objects in

space and time, but even space and time themselves disappear; and that these, as phenomena, cannot exist in

themselves, but only in us. What may be the nature of objects considered as things in themselves and without

reference to the receptivity of our sensibility is quite unknown to us. We know nothing more than our mode

of perceiving them, which is peculiar to us, and which, though not of necessity pertaining to every animated

being, is so to the whole human race. With this alone we have to do. Space and time are the pure forms

thereof; sensation the matter. The former alone can we cognize a priori, that is, antecedent to all actual

perception; and for this reason such cognition is called pure intuition. The latter is that in our cognition which

is called cognition a posteriori, that is, empirical intuition. The former appertain absolutely and necessarily to

our sensibility, of whatsoever kind our sensations may be; the latter may be of very diversified character.

Supposing that we should carry our empirical intuition even to the very highest degree of clearness, we

should not thereby advance one step nearer to a knowledge of the constitution of objects as things in

themselves. For we could only, at best, arrive at a complete cognition of our own mode of intuition, that is of

our sensibility, and this always under the conditions originally attaching to the subject, namely, the conditions

of space and time; while the question: "What are objects considered as things in themselves?" remains

To say, then, that all our sensibility is nothing but the confused representation of things containing

exclusively that which belongs to them as things in themselves, and this under an accumulation of

characteristic marks and partial representations which we cannot distinguish in consciousness, is a

falsification of the conception of sensibility and phenomenization, which renders our whole doctrine thereof

empty and useless. The difference between a confused and a clear representation is merely logical and has

nothing to do with content. No doubt the conception of right, as employed by a sound understanding, contains

all that the most subtle investigation could unfold from it, although, in the ordinary practical use of the word,

we are not conscious of the manifold representations comprised in the conception. But we cannot for this

reason assert that the ordinary conception is a sensuous one, containing a mere phenomenon, for right cannot

appear as a phenomenon; but the conception of it lies in the understanding, and represents a property (the

moral property) of actions, which belongs to them in themselves. On the other hand, the representation in

intuition of a body contains nothing which could belong to an object considered as a thing in itself, but

merely the phenomenon or appearance of something, and the mode in which we are affected by that

appearance; and this receptivity of our faculty of cognition is called sensibility, and remains toto caelo

different from the cognition of an object in itself, even though we should examine the content of the

It must be admitted that the LeibnitzWolfian philosophy has assigned an entirely erroneous point of view to

all investigations into the nature and origin of our cognitions, inasmuch as it regards the distinction between

the sensuous and the intellectual as merely logical, whereas it is plainly transcendental, and concerns not

merely the clearness or obscurity, but the content and origin of both. For the faculty of sensibility not only

does not present us with an indistinct and confused cognition of objects as things in themselves, but, in fact,

gives us no knowledge of these at all. On the contrary, so soon as we abstract in thought our own subjective

nature, the object represented, with the properties ascribed to it by sensuous intuition, entirely disappears,

because it was only this subjective nature that determined the form of the object as a phenomenon.

In phenomena, we commonly, indeed, distinguish that which essentially belongs to the intuition of them, and

is valid for the sensuous faculty of every human being, from that which belongs to the same intuition

accidentally, as valid not for the sensuous faculty in general, but for a particular state or organization of this

or that sense. Accordingly, we are accustomed to say that the former is a cognition which represents the

object itself, whilst the latter presents only a particular appearance or phenomenon thereof. This distinction,

however, is only empirical. If we stop here (as is usual), and do not regard the empirical intuition as itself a

mere phenomenon (as we ought to do), in which nothing that can appertain to a thing in itself is to be found,

our transcendental distinction is lost, and we believe that we cognize objects as things in themselves,

although in the whole range of the sensuous world, investigate the nature of its objects as profoundly as we

may, we have to do with nothing but phenomena. Thus, we call the rainbow a mere appearance of

phenomenon in a sunny shower, and the rain, the reality or thing in itself; and this is right enough, if we

understand the latter conception in a merely physical sense, that is, as that which in universal experience, and

under whatever conditions of sensuous perception, is known in intuition to be so and so determined, and not

otherwise. But if we consider this empirical datum generally, and inquire, without reference to its accordance

with all our senses, whether there can be discovered in it aught which represents an object as a thing in itself

(the raindrops of course are not such, for they are, as phenomena, empirical objects), the question of the

relation of the representation to the object is transcendental; and not only are the raindrops mere phenomena,

but even their circular form, nay, the space itself through which they fall, is nothing in itself, but both are

mere modifications or fundamental dispositions of our sensuous intuition, whilst the transcendental object

The second important concern of our aesthetic is that it does not obtain favour merely as a plausible

hypothesis, but possess as undoubted a character of certainty as can be demanded of any theory which is to

serve for an organon. In order fully to convince the reader of this certainty, we shall select a case which will

serve to make its validity apparent, and also to illustrate what has been said in SS 3.

Suppose, then, that space and time are in themselves objective, and conditions of the possibility of objects

as things in themselves. In the first place, it is evident that both present us, with very many apodeictic and

synthetic propositions a priori, but especially space and for this reason we shall prefer it for investigation at

present. As the propositions of geometry are cognized synthetically a priori, and with apodeictic certainty, I

inquire: Whence do you obtain propositions of this kind, and on what basis does the understanding rest, in

There is no other way than through intuitions or conceptions, as such; and these are given either a priori or a

posteriori. The latter, namely, empirical conceptions, together with the empirical intuition on which they are

founded, cannot afford any synthetical proposition, except such as is itself also empirical, that is, a

proposition of experience. But an empirical proposition cannot possess the qualities of necessity and absolute

universality, which, nevertheless, are the characteristics of all geometrical propositions. As to the first and

only means to arrive at such cognitions, namely, through mere conceptions or intuitions a priori, it is quite

clear that from mere conceptions no synthetical cognitions, but only analytical ones, can be obtained. Take,

for example, the proposition: "Two straight lines cannot enclose a space, and with these alone no figure is

possible," and try to deduce it from the conception of a straight line and the number two; or take the

proposition: "It is possible to construct a figure with three straight lines," and endeavour, in like manner, to

deduce it from the mere conception of a straight line and the number three. All your endeavours are in vain,

and you find yourself forced to have recourse to intuition, as, in fact, geometry always does. You therefore

give yourself an object in intuition. But of what kind is this intuition? Is it a pure a priori, or is it an empirical

intuition? If the latter, then neither an universally valid, much less an apodeictic proposition can arise from it,

for experience never can give us any such proposition. You must, therefore, give yourself an object a priori in

intuition, and upon that ground your synthetical proposition. Now if there did not exist within you a faculty of

intuition a priori; if this subjective condition were not in respect to its form also the universal condition a

priori under which alone the object of this external intuition is itself possible; if the object (that is, the

triangle) were something in itself, without relation to you the subject; how could you affirm that that which

lies necessarily in your subjective conditions in order to construct a triangle, must also necessarily belong to

the triangle in itself? For to your conceptions of three lines, you could not add anything new (that is, the

figure); which, therefore, must necessarily be found in the object, because the object is given before your

cognition, and not by means of it. If, therefore, space (and time also) were not a mere form of your intuition,

which contains conditions a priori, under which alone things can become external objects for you, and

without which subjective conditions the objects are in themselves nothing, you could not construct any

synthetical proposition whatsoever regarding external objects. It is therefore not merely possible or probable,

but indubitably certain, that space and time, as the necessary conditions of all our external and internal

experience, are merely subjective conditions of all our intuitions, in relation to which all objects are therefore

mere phenomena, and not things in themselves, presented to us in this particular manner. And for this reason,

in respect to the form of phenomena, much may be said a priori, whilst of the thing in itself, which may lie at

II. In confirmation of this theory of the ideality of the external as well as internal sense, consequently of all

objects of sense, as mere phenomena, we may especially remark that all in our cognition that belongs to

intuition contains nothing more than mere relations. (The feelings of pain and pleasure, and the will, which

are not cognitions, are excepted.) The relations, to wit, of place in an intuition (extension), change of place

(motion), and laws according to which this change is determined (moving forces). That, however, which is

present in this or that place, or any operation going on, or result taking place in the things themselves, with

the exception of change of place, is not given to us by intuition. Now by means of mere relations, a thing

cannot be known in itself; and it may therefore be fairly concluded, that, as through the external sense

nothing but mere representations of relations are given us, the said external sense in its representation can

contain only the relation of the object to the subject, but not the essential nature of the object as a thing in

The same is the case with the internal intuition, not only because, in the internal intuition, the representation

of the external senses constitutes the material with which the mind is occupied; but because time, in which we

place, and which itself antecedes the consciousness of, these representations in experience, and which, as the

formal condition of the mode according to which objects are placed in the mind, lies at the foundation of

them, contains relations of the successive, the coexistent, and of that which always must be coexistent with

succession, the permanent. Now that which, as representation, can antecede every exercise of thought (of an

object), is intuition; and when it contains nothing but relations, it is the form of the intuition, which, as it

presents us with no representation, except in so far as something is placed in the mind, can be nothing else

than the mode in which the mind is affected by its own activity, to wit its presenting to itself

representations, consequently the mode in which the mind is affected by itself; that is, it can be nothing but

an internal sense in respect to its form. Everything that is represented through the medium of sense is so far

phenomenal; consequently, we must either refuse altogether to admit an internal sense, or the subject, which

is the object of that sense, could only be represented by it as phenomenon, and not as it would judge of itself,

if its intuition were pure spontaneous activity, that is, were intellectual. The difficulty here lies wholly in the

question: How can the subject have an internal intuition of itself? But this difficulty is common to every

theory. The consciousness of self (apperception) is the simple representation of the "ego"; and if by means of

that representation alone, all the manifold representations in the subject were spontaneously given, then our

internal intuition would be intellectual. This consciousness in man requires an internal perception of the

manifold representations which are previously given in the subject; and the manner in which these

representations are given in the mind without spontaneity, must, on account of this difference (the want of

spontaneity), be called sensibility. If the faculty of selfconsciousness is to apprehend what lies in the mind,

it must all act that and can in this way alone produce an intuition of self. But the form of this intuition, which

lies in the original constitution of the mind, determines, in the representation of time, the manner in which the

manifold representations are to combine themselves in the mind; since the subject intuites itself, not as it

would represent itself immediately and spontaneously, but according to the manner in which the mind is

III. When we say that the intuition of external objects, and also the selfintuition of the subject, represent

both, objects and subject, in space and time, as they affect our senses, that is, as they appear this is by no

means equivalent to asserting that these objects are mere illusory appearances. For when we speak of things

as phenomena, the objects, nay, even the properties which we ascribe to them, are looked upon as really

given; only that, in so far as this or that property depends upon the mode of intuition of the subject, in the

relation of the given object to the subject, the object as phenomenon is to be distinguished from the object as

a thing in itself. Thus I do not say that bodies seem or appear to be external to me, or that my soul seems

merely to be given in my selfconsciousness, although I maintain that the properties of space and time, in

conformity to which I set both, as the condition of their existence, abide in my mode of intuition, and not in

the objects in themselves. It would be my own fault, if out of that which I should reckon as phenomenon, I

made mere illusory appearance.* But this will not happen, because of our principle of the ideality of all

sensuous intuitions. On the contrary, if we ascribe objective reality to these forms of representation, it

becomes impossible to avoid changing everything into mere appearance. For if we regard space and time as

properties, which must be found in objects as things in themselves, as sine quibus non of the possibility of

their existence, and reflect on the absurdities in which we then find ourselves involved, inasmuch as we are

compelled to admit the existence of two infinite things, which are nevertheless not substances, nor anything

really inhering in substances, nay, to admit that they are the necessary conditions of the existence of all

things, and moreover, that they must continue to exist, although all existing things were annihilated we

cannot blame the good Berkeley for degrading bodies to mere illusory appearances. Nay, even our own

existence, which would in this case depend upon the selfexistent reality of such a mere nonentity as time,

would necessarily be changed with it into mere appearance an absurdity which no one has as yet been guilty

*The predicates of the phenomenon can be affixed to the object itself in relation to our sensuous faculty; for

example, the red colour or the perfume to the rose. But (illusory) appearance never can be attributed as a

predicate to an object, for this very reason, that it attributes to this object in itself that which belongs to it only

in relation to our sensuous faculty, or to the subject in general, e.g., the two handles which were formerly

ascribed to Saturn. That which is never to be found in the object itself, but always in the relation of the object

to the subject, and which moreover is inseparable from our representation of the object, we denominate

phenomenon. Thus the predicates of space and time are rightly attributed to objects of the senses as such, and

in this there is no illusion. On the contrary, if I ascribe redness of the rose as a thing in itself, or to Saturn his

handles, or extension to all external objects, considered as things in themselves, without regarding the

determinate relation of these objects to the subject, and without limiting my judgement to that relation then,

IV. In natural theology, where we think of an object God which never can be an object of intuition to us,

and even to himself can never be an object of sensuous intuition, we carefully avoid attributing to his

intuition the conditions of space and time and intuition all his cognition must be, and not thought, which

always includes limitation. But with what right can we do this if we make them forms of objects as things in

themselves, and such, moreover, as would continue to exist as a priori conditions of the existence of things,

even though the things themselves were annihilated? For as conditions of all existence in general, space and

time must be conditions of the existence of the Supreme Being also. But if we do not thus make them

objective forms of all things, there is no other way left than to make them subjective forms of our mode of

intuition external and internal; which is called sensuous, because it is not primitive, that is, is not such as

gives in itself the existence of the object of the intuition (a mode of intuition which, so far as we can judge,

can belong only to the Creator), but is dependent on the existence of the object, is possible, therefore, only on

condition that the representative faculty of the subject is affected by the object.

It is, moreover, not necessary that we should limit the mode of intuition in space and time to the sensuous

faculty of man. It may well be that all finite thinking beings must necessarily in this respect agree with man

(though as to this we cannot decide), but sensibility does not on account of this universality cease to be

sensibility, for this very reason, that it is a deduced (intuitus derivativus), and not an original (intuitus

originarius), consequently not an intellectual intuition, and this intuition, as such, for reasons above

mentioned, seems to belong solely to the Supreme Being, but never to a being dependent, quoad its existence,

as well as its intuition (which its existence determines and limits relatively to given objects). This latter

remark, however, must be taken only as an illustration, and not as any proof of the truth of our aesthetical

We have now completely before us one part of the solution of the grand general problem of transcendental

philosophy, namely, the question: "How are synthetical propositions a priori possible?" That is to say, we

have shown that we are in possession of pure a priori intuitions, namely, space and time, in which we find,

when in a judgement a priori we pass out beyond the given conception, something which is not discoverable

in that conception, but is certainly found a priori in the intuition which corresponds to the conception, and can

be united synthetically with it. But the judgements which these pure intuitions enable us to make, never reach

farther than to objects of the senses, and are valid only for objects of possible experience. INTRO

Our knowledge springs from two main sources in the mind, first of which is the faculty or power of receiving

representations (receptivity for impressions); the second is the power of cognizing by means of these

representations (spontaneity in the production of conceptions). Through the first an object is given to us;

through the second, it is, in relation to the representation (which is a mere determination of the mind),

thought. Intuition and conceptions constitute, therefore, the elements of all our knowledge, so that neither

conceptions without an intuition in some way corresponding to them, nor intuition without conceptions, can

afford us a cognition. Both are either pure or empirical. They are. empirical, when sensation (which

presupposes the actual presence of the object) is contained in them; and pure, when no sensation is mixed

with the representation. Sensations we may call the matter of sensuous cognition. Pure intuition consequently

contains merely the form under which something is intuited, and pure conception only the form of the

thought of an object. Only pure intuitions and pure conceptions are possible a priori; the empirical only a

We apply the term sensibility to the receptivity of the mind for impressions, in so far as it is in some way

affected; and, on the other hand, we call the faculty of spontaneously producing representations, or the

spontaneity of cognition, understanding. Our nature is so constituted that intuition with us never can be other

than sensuous, that is, it contains only the mode in which we are affected by objects. On the other hand, the

faculty of thinking the object of sensuous intuition is the understanding. Neither of these faculties has a

preference over the other. Without the sensuous faculty no object would be given to us, and without the

understanding no object would be thought. Thoughts without content are void; intuitions without

conceptions, blind. Hence it is as necessary for the mind to make its conceptions sensuous (that is, to join to

them the object in intuition), as to make its intuitions intelligible (that is, to bring them under conceptions).

Neither of these faculties can exchange its proper function. Understanding cannot intuite, and the sensuous

faculty cannot think. in no other way than from the united operation of both, can knowledge arise. But no one

ought, on this account, to overlook the difference of the elements contributed by each; we have rather great

reason carefully to separate and distinguish them. We therefore distinguish the science of the laws of

sensibility, that is, aesthetic, from the science of the laws of the understanding, that is, logic.

Now, logic in its turn may be considered as twofold namely, as logic of the general, or of the particular use

of the understanding. The first contains the absolutely necessary laws of thought, without which no use

whatsoever of the understanding is possible, and gives laws therefore to the understanding, without regard to

the difference of objects on which it may be employed. The logic of the particular use of the understanding

contains the laws of correct thinking upon a particular class of objects. The former may be called elemental

logic the latter, the organon of this or that particular science. The latter is for the most part employed in the

schools, as a propaedeutic to the sciences, although, indeed, according to the course of human reason, it is the

last thing we arrive at, when the science has been already matured, and needs only the finishing touches

towards its correction and completion; for our knowledge of the objects of our attempted science must be

tolerably extensive and complete before we can indicate the laws by which a science of these objects can be

General logic is again either pure or applied. In the former, we abstract all the empirical conditions under

which the understanding is exercised; for example, the influence of the senses, the play of the fantasy or

imagination, the laws of the memory, the force of habit, of inclination, etc., consequently also, the sources of

prejudice in a word, we abstract all causes from which particular cognitions arise, because these causes

regard the understanding under certain circumstances of its application, and, to the knowledge of them

experience is required. Pure general logic has to do, therefore, merely with pure a priori principles, and is a

canon of understanding and reason, but only in respect of the formal part of their use, be the content what it

may, empirical or transcendental. General logic is called applied, when it is directed to the laws of the use of

the understanding, under the subjective empirical conditions which psychology teaches us. It has therefore

empirical principles, although, at the same time, it is in so far general, that it applies to the exercise of the

understanding, without regard to the difference of objects. On this account, moreover, it is neither a canon of

the understanding in general, nor an organon of a particular science, but merely a cathartic of the human

In general logic, therefore, that part which constitutes pure logic must be carefully distinguished from that

which constitutes applied (though still general) logic. The former alone is properly science, although short

and dry, as the methodical exposition of an elemental doctrine of the understanding ought to be. In this,

1. As general logic, it makes abstraction of all content of the cognition of the understanding, and of the

2. As pure logic, it has no empirical principles, and consequently draws nothing (contrary to the common

persuasion) from psychology, which therefore has no influence on the canon of the understanding. It is a

demonstrated doctrine, and everything in it must be certain completely a priori.

What I called applied logic (contrary to the common acceptation of this term, according to which it should

contain certain exercises for the scholar, for which pure logic gives the rules), is a representation of the

understanding, and of the rules of its necessary employment in concreto, that is to say, under the accidental

conditions of the subject, which may either hinder or promote this employment, and which are all given only

empirically. Thus applied logic treats of attention, its impediments and consequences, of the origin of error,

of the state of doubt, hesitation, conviction, etc., and to it is related pure general logic in the same way that

pure morality, which contains only the necessary moral laws of a free will, is related to practical ethics, which

considers these laws under all the impediments of feelings, inclinations, and passions to which men are more

or less subjected, and which never can furnish us with a true and demonstrated science, because it, as well as

General logic, as we have seen, makes abstraction of all content of cognition, that is, of all relation of

cognition to its object, and regards only the logical form in the relation of cognitions to each other, that is, the

form of thought in general. But as we have both pure and empirical intuitions (as transcendental aesthetic

proves), in like manner a distinction might be drawn between pure and empirical thought (of objects). In this

case, there would exist a kind of logic, in which we should not make abstraction of all content of cognition;

for or logic which should comprise merely the laws of pure thought (of an object), would of course exclude

all those cognitions which were of empirical content. This kind of logic would also examine the origin of our

cognitions of objects, so far as that origin cannot be ascribed to the objects themselves; while, on the

contrary, general logic has nothing to do with the origin of our cognitions, but contemplates our

representations, be they given primitively a priori in ourselves, or be they only of empirical origin, solely

according to the laws which the understanding observes in employing them in the process of thought, in

relation to each other. Consequently, general logic treats of the form of the understanding only, which can be

And here I shall make a remark, which the reader must bear well in mind in the course of the following

considerations, to wit, that not every cognition a priori, but only those through which we cognize that and

how certain representations (intuitions or conceptions) are applied or are possible only a priori; that is to say,

the a priori possibility of cognition and the a priori use of it are transcendental. Therefore neither is space, nor

any a priori geometrical determination of space, a transcendental Representation, but only the knowledge that

such a representation is not of empirical origin, and the possibility of its relating to objects of experience,

although itself a priori, can be called transcendental. So also, the application of space to objects in general

would be transcendental; but if it be limited to objects of sense it is empirical. Thus, the distinction of the

transcendental and empirical belongs only to the critique of cognitions, and does not concern the relation of

Accordingly, in the expectation that there may perhaps be conceptions which relate a priori to objects, not as

pure or sensuous intuitions, but merely as acts of pure thought (which are therefore conceptions, but neither

of empirical nor aesthetical origin) in this expectation, I say, we form to ourselves, by anticipation, the idea

of a science of pure understanding and rational cognition, by means of which we may cogitate objects

entirely a priori. A science of this kind, which should determine the origin, the extent, and the objective

validity of such cognitions, must be called transcendental logic, because it has not, like general logic, to do

with the laws of understanding and reason in relation to empirical as well as pure rational cognitions without

distinction, but concerns itself with these only in an a priori relation to objects.

The old question with which people sought to push logicians into a corner, so that they must either have

recourse to pitiful sophisms or confess their ignorance, and consequently the vanity of their whole art, is this:

"What is truth?" The definition of the word truth, to wit, "the accordance of the cognition with its object," is

presupposed in the question; but we desire to be told, in the answer to it, what is the universal and secure

To know what questions we may reasonably propose is in itself a strong evidence of sagacity and

intelligence. For if a question be in itself absurd and unsusceptible of a rational answer, it is attended with the

danger not to mention the shame that falls upon the person who proposes it of seducing the unguarded

listener into making absurd answers, and we are presented with the ridiculous spectacle of one (as the

If truth consists in the accordance of a cognition with its object, this object must be, ipso facto, distinguished

from all others; for a cognition is false if it does not accord with the object to which it relates, although it

contains something which may be affirmed of other objects. Now an universal criterion of truth would be that

which is valid for all cognitions, without distinction of their objects. But it is evident that since, in the case of

such a criterion, we make abstraction of all the content of a cognition (that is, of all relation to its object), and

truth relates precisely to this content, it must be utterly absurd to ask for a mark of the truth of this content of

cognition; and that, accordingly, a sufficient, and at the same time universal, test of truth cannot possibly be

found. As we have already termed the content of a cognition its matter, we shall say: "Of the truth of our

cognitions in respect of their matter, no universal test can be demanded, because such a demand is

On the other hand, with regard to our cognition in respect of its mere form (excluding all content), it is

equally manifest that logic, in so far as it exhibits the universal and necessary laws of the understanding, must

in these very laws present us with criteria of truth. Whatever contradicts these rules is false, because thereby

the understanding is made to contradict its own universal laws of thought; that is, to contradict itself. These

criteria, however, apply solely to the form of truth, that is, of thought in general, and in so far they are

perfectly accurate, yet not sufficient. For although a cognition may be perfectly accurate as to logical form,

that is, not selfcontradictory, it is notwithstanding quite possible that it may not stand in agreement with its

object. Consequently, the merely logical criterion of truth, namely, the accordance of a cognition with the

universal and formal laws of understanding and reason, is nothing more than the conditio sine qua non, or

negative condition of all truth. Farther than this logic cannot go, and the error which depends not on the form,

General logic, then, resolves the whole formal business of understanding and reason into its elements, and

exhibits them as principles of all logical judging of our cognitions. This part of logic may, therefore, be called

analytic, and is at least the negative test of truth, because all cognitions must first of an be estimated and tried

according to these laws before we proceed to investigate them in respect of their content, in order to discover

whether they contain positive truth in regard to their object. Because, however, the mere form of a cognition,

accurately as it may accord with logical laws, is insufficient to supply us with material (objective) truth, no

one, by means of logic alone, can venture to predicate anything of or decide concerning objects, unless he has

obtained, independently of logic, wellgrounded information about them, in order afterwards to examine,

according to logical laws, into the use and connection, in a cohering whole, of that information, or, what is

still better, merely to test it by them. Notwithstanding, there lies so seductive a charm in the possession of a

specious art like this an art which gives to all our cognitions the form of the understanding, although with

respect to the content thereof we may be sadly deficient that general logic, which is merely a canon of

judgement, has been employed as an organon for the actual production, or rather for the semblance of

production, of objective assertions, and has thus been grossly misapplied. Now general logic, in its assumed

Different as are the significations in which the ancients used this term for a science or an art, we may safely

infer, from their actual employment of it, that with them it was nothing else than a logic of illusion a

sophistical art for giving ignorance, nay, even intentional sophistries, the colouring of truth, in which the

thoroughness of procedure which logic requires was imitated, and their topic employed to cloak the empty

pretensions. Now it may be taken as a safe and useful warning, that general logic, considered as an organon,

must always be a logic of illusion, that is, be dialectical, for, as it teaches us nothing whatever respecting the

content of our cognitions, but merely the formal conditions of their accordance with the understanding, which

do not relate to and are quite indifferent in respect of objects, any attempt to employ it as an instrument

(organon) in order to extend and enlarge the range of our knowledge must end in mere prating; any one being

able to maintain or oppose, with some appearance of truth, any single assertion whatever.

Such instruction is quite unbecoming the dignity of philosophy. For these reasons we have chosen to

denominate this part of logic dialectic, in the sense of a critique of dialectical illusion, and we wish the term

In transcendental logic we isolate the understanding (as in transcendental aesthetic the sensibility) and select

from our cognition merely that part of thought which has its origin in the understanding alone. The exercise

of this pure cognition, however, depends upon this as its condition, that objects to which it may be applied be

given to us in intuition, for without intuition the whole of our cognition is without objects, and is therefore

quite void. That part of transcendental logic, then, which treats of the elements of pure cognition of the

understanding, and of the principles without which no object at all can be thought, is transcendental analytic,

and at the same time a logic of truth. For no cognition can contradict it, without losing at the same time all

content, that is, losing all reference to an object, and therefore all truth. But because we are very easily

seduced into employing these pure cognitions and principles of the understanding by themselves, and that

even beyond the boundaries of experience, which yet is the only source whence we can obtain matter

(objects) on which those pure conceptions may be employed understanding runs the risk of making, by

means of empty sophisms, a material and objective use of the mere formal principles of the pure

understanding, and of passing judgements on objects without distinction objects which are not given to us,

nay, perhaps cannot be given to us in any way. Now, as it ought properly to be only a canon for judging of

the empirical use of the understanding, this kind of logic is misused when we seek to employ it as an organon

of the universal and unlimited exercise of the understanding, and attempt with the pure understanding alone

to judge synthetically, affirm, and determine respecting objects in general. In this case the exercise of the

pure understanding becomes dialectical. The second part of our transcendental logic must therefore be a

critique of dialectical illusion, and this critique we shall term transcendental dialectic not meaning it as an

art of producing dogmatically such illusion (an art which is unfortunately too current among the practitioners

of metaphysical juggling), but as a critique of understanding and reason in regard to their hyperphysical use.

This critique will expose the groundless nature of the pretensions of these two faculties, and invalidate their

claims to the discovery and enlargement of our cognitions merely by means of transcendental principles, and

show that the proper employment of these faculties is to test the judgements made by the pure understanding,

Transcendental analytic is the dissection of the whole of our a priori knowledge into the elements of the pure

cognition of the understanding. In order to effect our purpose, it is necessary: (1) That the conceptions be

pure and not empirical; (2) That they belong not to intuition and sensibility, but to thought and understanding;

(3) That they be elementary conceptions, and as such, quite different from deduced or compound

conceptions; (4) That our table of these elementary conceptions be complete, and fill up the whole sphere of

the pure understanding. Now this completeness of a science cannot be accepted with confidence on the

guarantee of a mere estimate of its existence in an aggregate formed only by means of repeated experiments

and attempts. The completeness which we require is possible only by means of an idea of the totality of the a

priori cognition of the understanding, and through the thereby determined division of the conceptions which

form the said whole; consequently, only by means of their connection in a system. Pure understanding

distinguishes itself not merely from everything empirical, but also completely from all sensibility. It is a unity

selfsubsistent, selfsufficient, and not to be enlarged by any additions from without. Hence the sum of its

cognition constitutes a system to be determined by and comprised under an idea; and the completeness and

articulation of this system can at the same time serve as a test of the correctness and genuineness of all the

parts of cognition that belong to it. The whole of this part of transcendental logic consists of two books, of

which the one contains the conceptions, and the other the principles of pure understanding.

By the term Analytic of Conceptions, I do not understand the analysis of these, or the usual process in

philosophical investigations of dissecting the conceptions which present themselves, according to their

content, and so making them clear; but I mean the hitherto little attempted dissection of the faculty of

understanding itself, in order to investigate the possibility of conceptions a priori, by looking for them in the

understanding alone, as their birthplace, and analysing the pure use of this faculty. For this is the proper duty

of a transcendental philosophy; what remains is the logical treatment of the conceptions in philosophy in

general. We shall therefore follow up the pure conceptions even to their germs and beginnings in the human

understanding, in which they lie, until they are developed on occasions presented by experience, and, freed

by the same understanding from the empirical conditions attaching to them, are set forth in their unalloyed

When we call into play a faculty of cognition, different conceptions manifest themselves according to the

different circumstances, and make known this faculty, and assemble themselves into a more or less extensive

collection, according to the time or penetration that has been applied to the consideration of them. Where this

process, conducted as it is mechanically, so to speak, will end, cannot be determined with certainty. Besides,

the conceptions which we discover in this haphazard manner present themselves by no means in order and

systematic unity, but are at last coupled together only according to resemblances to each other, and arranged

in series, according to the quantity of their content, from the simpler to the more complex series which are

anything but systematic, though not altogether without a certain kind of method in their construction.

Transcendental philosophy has the advantage, and moreover the duty, of searching for its conceptions

according to a principle; because these conceptions spring pure and unmixed out of the understanding as an

absolute unity, and therefore must be connected with each other according to one conception or idea. A

connection of this kind, however, furnishes us with a ready prepared rule, by which its proper place may be

assigned to every pure conception of the understanding, and the completeness of the system of all be

determined a priori both which would otherwise have been dependent on mere choice or chance.

The understanding was defined above only negatively, as a nonsensuous faculty of cognition. Now,

independently of sensibility, we cannot possibly have any intuition; consequently, the understanding is no

faculty of intuition. But besides intuition there is no other mode of cognition, except through conceptions;

consequently, the cognition of every, at least of every human, understanding is a cognition through

conceptions not intuitive, but discursive. All intuitions, as sensuous, depend on affections; conceptions,

therefore, upon functions. By the word function I understand the unity of the act of arranging diverse

representations under one common representation. Conceptions, then, are based on the spontaneity of

thought, as sensuous intuitions are on the receptivity of impressions. Now, the understanding cannot make

any other use of these conceptions than to judge by means of them. As no representation, except an intuition,

relates immediately to its object, a conception never relates immediately to an object, but only to some other

representation thereof, be that an intuition or itself a conception. A judgement, therefore, is the mediate

cognition of an object, consequently the representation of a representation of it. In every judgement there is a

conception which applies to, and is valid for many other conceptions, and which among these comprehends

also a given representation, this last being immediately connected with an object. For example, in the

judgement "All bodies are divisible," our conception of divisible applies to various other conceptions;

among these, however, it is here particularly applied to the conception of body, and this conception of body

relates to certain phenomena which occur to us. These objects, therefore, are mediately represented by the

conception of divisibility. All judgements, accordingly, are functions of unity in our representations,

inasmuch as, instead of an immediate, a higher representation, which comprises this and various others, is

used for our cognition of the object, and thereby many possible cognitions are collected into one. But we can

reduce all acts of the understanding to judgements, so that understanding may be represented as the faculty of

judging. For it is, according to what has been said above, a faculty of thought. Now thought is cognition by

means of conceptions. But conceptions, as predicates of possible judgements, relate to some representation of

a yet undetermined object. Thus the conception of body indicates something for example, metal which can

be cognized by means of that conception. It is therefore a conception, for the reason alone that other

representations are contained under it, by means of which it can relate to objects. It is therefore the predicate

to a possible judgement; for example: "Every metal is a body." All the functions of the understanding

therefore can be discovered, when we can completely exhibit the functions of unity in judgements. And that

If we abstract all the content of a judgement, and consider only the intellectual form thereof, we find that the

function of thought in a judgement can be brought under four heads, of which each contains three momenta.

As this division appears to differ in some, though not essential points, from the usual technique of logicians,

the following observations, for the prevention of otherwise possible misunderstanding, will not be without

1. Logicians say, with justice, that in the use of judgements in syllogisms, singular judgements may be treated

like universal ones. For, precisely because a singular judgement has no extent at all, its predicate cannot refer

to a part of that which is contained in the conception of the subject and be excluded from the rest. The

predicate is valid for the whole conception just as if it were a general conception, and had extent, to the whole

of which the predicate applied. On the other hand, let us compare a singular with a general judgement, merely

as a cognition, in regard to quantity. The singular judgement relates to the general one, as unity to infinity,

and is therefore in itself essentially different. Thus, if we estimate a singular judgement (judicium singulare)

not merely according to its intrinsic validity as a judgement, but also as a cognition generally, according to its

quantity in comparison with that of other cognitions, it is then entirely different from a general judgement

(judicium commune), and in a complete table of the momenta of thought deserves a separate place though,

indeed, this would not be necessary in a logic limited merely to the consideration of the use of judgements in

2. In like manner, in transcendental logic, infinite must be distinguished from affirmative judgements,

although in general logic they are rightly enough classed under affirmative. General logic abstracts all content

of the predicate (though it be negative), and only considers whether the said predicate be affirmed or denied

of the subject. But transcendental logic considers also the worth or content of this logical affirmation an

affirmation by means of a merely negative predicate, and inquires how much the sum total of our cognition

gains by this affirmation. For example, if I say of the soul, "It is not mortal" by this negative judgement I

should at least ward off error. Now, by the proposition, "The soul is not mortal," I have, in respect of the

logical form, really affirmed, inasmuch as I thereby place the soul in the unlimited sphere of immortal beings.

Now, because of the whole sphere of possible existences, the mortal occupies one part, and the immortal the

other, neither more nor less is affirmed by the proposition than that the soul is one among the infinite

multitude of things which remain over, when I take away the whole mortal part. But by this proceeding we

accomplish only this much, that the infinite sphere of all possible existences is in so far limited that the

mortal is excluded from it, and the soul is placed in the remaining part of the extent of this sphere. But this

part remains, notwithstanding this exception, infinite, and more and more parts may be taken away from the

whole sphere, without in the slightest degree thereby augmenting or affirmatively determining our conception

of the soul. These judgements, therefore, infinite in respect of their logical extent, are, in respect of the

content of their cognition, merely limitative; and are consequently entitled to a place in our transcendental

table of all the momenta of thought in judgements, because the function of the understanding exercised by

3. All relations of thought in judgements are those (a) of the predicate to the subject; (b) of the principle to its

consequence; (c) of the divided cognition and all the members of the division to each other. In the first of

these three classes, we consider only two conceptions; in the second, two judgements; in the third, several

judgements in relation to each other. The hypothetical proposition, "If perfect justice exists, the obstinately

wicked are punished," contains properly the relation to each other of two propositions, namely, "Perfect

justice exists," and "The obstinately wicked are punished." Whether these propositions are in themselves true

is a question not here decided. Nothing is cogitated by means of this judgement except a certain consequence.

Finally, the disjunctive judgement contains a relation of two or more propositions to each other a relation

not of consequence, but of logical opposition, in so far as the sphere of the one proposition excludes that of

the other. But it contains at the same time a relation of community, in so far as all the propositions taken

together fill up the sphere of the cognition. The disjunctive judgement contains, therefore, the relation of the

parts of the whole sphere of a cognition, since the sphere of each part is a complemental part of the sphere of

the other, each contributing to form the sum total of the divided cognition. Take, for example, the

proposition, "The world exists either through blind chance, or through internal necessity, or through an

external cause." Each of these propositions embraces a part of the sphere of our possible cognition as to the

existence of a world; all of them taken together, the whole sphere. To take the cognition out of one of these

spheres, is equivalent to placing it in one of the others; and, on the other hand, to place it in one sphere is

equivalent to taking it out of the rest. There is, therefore, in a disjunctive judgement a certain community of

cognitions, which consists in this, that they mutually exclude each other, yet thereby determine, as a whole,

the true cognition, inasmuch as, taken together, they make up the complete content of a particular given

cognition. And this is all that I find necessary, for the sake of what follows, to remark in this place.

4. The modality of judgements is a quite peculiar function, with this distinguishing characteristic, that it

contributes nothing to the content of a judgement (for besides quantity, quality, and relation, there is nothing

more that constitutes the content of a judgement), but concerns itself only with the value of the copula in

relation to thought in general. Problematical judgements are those in which the affirmation or negation is

accepted as merely possible (ad libitum). In the assertorical, we regard the proposition as real (true); in the

apodeictical, we look on it as necessary.* Thus the two judgements (antecedens et consequens), the relation

of which constitutes a hypothetical judgement, likewise those (the members of the division) in whose

reciprocity the disjunctive consists, are only problematical. In the example above given the proposition,

"There exists perfect justice," is not stated assertorically, but as an ad libitum judgement, which someone may

choose to adopt, and the consequence alone is assertorical. Hence such judgements may be obviously false,

and yet, taken problematically, be conditions of our cognition of the truth. Thus the proposition, "The world

exists only by blind chance," is in the disjunctive judgement of problematical import only: that is to say, one

may accept it for the moment, and it helps us (like the indication of the wrong road among all the roads that

one can take) to find out the true proposition. The problematical proposition is, therefore, that which

expresses only logical possibility (which is not objective); that is, it expresses a free choice to admit the

validity of such a proposition a merely arbitrary reception of it into the understanding. The assertorical

speaks of logical reality or truth; as, for example, in a hypothetical syllogism, the antecedens presents itself in

a problematical form in the major, in an assertorical form in the minor, and it shows that the proposition is in

harmony with the laws of the understanding. The apodeictical proposition cogitates the assertorical as

determined by these very laws of the understanding, consequently as affirming a priori, and in this manner it

expresses logical necessity. Now because all is here gradually incorporated with the understanding

inasmuch as in the first place we judge problematically; then accept assertorically our judgement as true;

lastly, affirm it as inseparably united with the understanding, that is, as necessary and apodeictical we may

*Just as if thought were in the first instance a function of the understanding; in the second, of judgement; in

General logic, as has been repeatedly said, makes abstraction of all content of cognition, and expects to

receive representations from some other quarter, in order, by means of analysis, to convert them into

conceptions. On the contrary, transcendental logic has lying before it the manifold content of a priori

sensibility, which transcendental aesthetic presents to it in order to give matter to the pure conceptions of the

understanding, without which transcendental logic would have no content, and be therefore utterly void. Now

space and time contain an infinite diversity of determinations of pure a priori intuition, but are nevertheless

the condition of the mind's receptivity, under which alone it can obtain representations of objects, and which,

consequently, must always affect the conception of these objects. But the spontaneity of thought requires that

this diversity be examined after a certain manner, received into the mind, and connected, in order afterwards

By the word synthesis, in its most general signification, I understand the process of joining different

representations to each other and of comprehending their diversity in one cognition. This synthesis is pure

when the diversity is not given empirically but a priori (as that in space and time). Our representations must

be given previously to any analysis of them; and no conceptions can arise, quoad their content, analytically.

But the synthesis of a diversity (be it given a priori or empirically) is the first requisite for the production of a

cognition, which in its beginning, indeed, may be crude and confused, and therefore in need of analysis still,

synthesis is that by which alone the elements of our cognitions are collected and united into a certain content,

consequently it is the first thing on which we must fix our attention, if we wish to investigate the origin of our

Synthesis, generally speaking, is, as we shall afterwards see, the mere operation of the imagination a blind

but indispensable function of the soul, without which we should have no cognition whatever, but of the

working of which we are seldom even conscious. But to reduce this synthesis to conceptions is a function of

the understanding, by means of which we attain to cognition, in the proper meaning of the term.

Pure synthesis, represented generally, gives us the pure conception of the understanding. But by this pure

synthesis, I mean that which rests upon a basis of a priori synthetical unity. Thus, our numeration (and this is

more observable in large numbers) is a synthesis according to conceptions, because it takes place according

to a common basis of unity (for example, the decade). By means of this conception, therefore, the unity in the

By means of analysis different representations are brought under one conception an operation of which

general logic treats. On the other hand, the duty of transcendental logic is to reduce to conceptions, not

representations, but the pure synthesis of representations. The first thing which must be given to us for the

sake of the a priori cognition of all objects, is the diversity of the pure intuition; the synthesis of this diversity

by means of the imagination is the second; but this gives, as yet, no cognition. The conceptions which give

unity to this pure synthesis, and which consist solely in the representation of this necessary synthetical unity,

furnish the third requisite for the cognition of an object, and these conceptions are given by the

The same function which gives unity to the different representation in a judgement, gives also unity to the

mere synthesis of different representations in an intuition; and this unity we call the pure conception of the

understanding. Thus, the same understanding, and by the same operations, whereby in conceptions, by means

of analytical unity, it produced the logical form of a judgement, introduces, by means of the synthetical unity

of the manifold in intuition, a transcendental content into its representations, on which account they are called

pure conceptions of the understanding, and they apply a priori to objects, a result not within the power of

In this manner, there arise exactly so many pure conceptions of the understanding, applying a priori to objects

of intuition in general, as there are logical functions in all possible judgements. For there is no other function

or faculty existing in the understanding besides those enumerated in that table. These conceptions we shall,

with Aristotle, call categories, our purpose being originally identical with his, notwithstanding the great

This, then, is a catalogue of all the originally pure conceptions of the synthesis which the understanding

contains a priori, and these conceptions alone entitle it to be called a pure understanding; inasmuch as only by

them it can render the manifold of intuition conceivable, in other words, think an object of intuition. This

division is made systematically from a common principle, namely the faculty of judgement (which is just the

same as the power of thought), and has not arisen rhapsodically from a search at haphazard after pure

conceptions, respecting the full number of which we never could be certain, inasmuch as we employ

induction alone in our search, without considering that in this way we can never understand wherefore

precisely these conceptions, and none others, abide in the pure understanding. It was a design worthy of an

acute thinker like Aristotle, to search for these fundamental conceptions. Destitute, however, of any guiding

principle, he picked them up just as they occurred to him, and at first hunted out ten, which he called

categories (predicaments). Afterwards be believed that he had discovered five others, which were added

under the name of post predicaments. But his catalogue still remained defective. Besides, there are to be

found among them some of the modes of pure sensibility (quando, ubi, situs, also prius, simul), and likewise

an empirical conception (motus) which can by no means belong to this genealogical register of the pure

understanding. Moreover, there are deduced conceptions (actio, passio) enumerated among the original

With regard to these, it is to be remarked, that the categories, as the true primitive conceptions of the pure

understanding, have also their pure deduced conceptions, which, in a complete system of transcendental

philosophy, must by no means be passed over; though in a merely critical essay we must be contented with

Let it be allowed me to call these pure, but deduced conceptions of the understanding, the predicables of the

pure understanding, in contradistinction to predicaments. If we are in possession of the original and primitive,

the deduced and subsidiary conceptions can easily be added, and the genealogical tree of the understanding

completely delineated. As my present aim is not to set forth a complete system, but merely the principles of

one, I reserve this task for another time. It may be easily executed by any one who will refer to the

ontological manuals, and subordinate to the category of causality, for example, the predicables of force,

action, passion; to that of community, those of presence and resistance; to the categories of modality, those of

origination, extinction, change; and so with the rest. The categories combined with the modes of pure

sensibility, or with one another, afford a great number of deduced a priori conceptions; a complete

enumeration of which would be a useful and not unpleasant, but in this place a perfectly dispensable,

I purposely omit the definitions of the categories in this treatise. I shall analyse these conceptions only so far

as is necessary for the doctrine of method, which is to form a part of this critique. In a system of pure reason,

definitions of them would be with justice demanded of me, but to give them here would only bide from our

view the main aim of our investigation, at the same time raising doubts and objections, the consideration of

which, without injustice to our main purpose, may be very well postponed till another opportunity.

Meanwhile, it ought to be sufficiently clear, from the little we have already said on this subject, that the

formation of a complete vocabulary of pure conceptions, accompanied by all the requisite explanations, is not

only a possible, but an easy undertaking. The compartments already exist; it is only necessary to fill them up;

and a systematic topic like the present, indicates with perfect precision the proper place to which each

conception belongs, while it readily points out any that have not yet been filled up.

Our table of the categories suggests considerations of some importance, which may perhaps have significant

results in regard to the scientific form of all rational cognitions. For, that this table is useful in the theoretical

part of philosophy, nay, indispensable for the sketching of the complete plan of a science, so far as that

science rests upon conceptions a priori, and for dividing it mathematically, according to fixed principles, is

most manifest from the fact that it contains all the elementary conceptions of the understanding, nay, even the

form of a system of these in the understanding itself, and consequently indicates all the momenta, and also

the internal arrangement of a projected speculative science, as I have elsewhere shown.* Here follow some of

I. This table, which contains four classes of conceptions of the understanding, may, in the first instance, be

divided into two classes, the first of which relates to objects of intuition pure as well as empirical; the

second, to the existence of these objects, either in relation to one another, or to the understanding.

The former of these classes of categories I would entitle the mathematical, and the latter the dynamical

categories. The former, as we see, has no correlates; these are only to be found in the second class. This

II. The number of the categories in each class is always the same, namely, three a fact which also demands

some consideration, because in all other cases division a priori through conceptions is necessarily dichotomy.

It is to be added, that the third category in each triad always arises from the combination of the second with

Thus totality is nothing else but plurality contemplated as unity; limitation is merely reality conjoined with

negation; community is the causality of a substance, reciprocally determining, and determined by other

substances; and finally, necessity is nothing but existence, which is given through the possibility itself. Let it

not be supposed, however, that the third category is merely a deduced, and not a primitive conception of the

pure understanding. For the conjunction of the first and second, in order to produce the third conception,

requires a particular function of the understanding, which is by no means identical with those which are

exercised in the first and second. Thus, the conception of a number (which belongs to the category of totality)

is not always possible, where the conceptions of multitude and unity exist (for example, in the representation

of the infinite). Or, if I conjoin the conception of a cause with that of a substance, it does not follow that the

conception of influence, that is, how one substance can be the cause of something in another substance, will

be understood from that. Thus it is evident that a particular act of the understanding is here necessary; and so

III. With respect to one category, namely, that of community, which is found in the third class, it is not so

easy as with the others to detect its accordance with the form of the disjunctive judgement which corresponds

In order to assure ourselves of this accordance, we must observe that in every disjunctive judgement, the

sphere of the judgement (that is, the complex of all that is contained in it) is represented as a whole divided

into parts; and, since one part cannot be contained in the other, they are cogitated as coordinated with, not

subordinated to each other, so that they do not determine each other unilaterally, as in a linear series, but

reciprocally, as in an aggregate (if one member of the division is posited, all the rest are excluded; and

Now a like connection is cogitated in a whole of things; for one thing is not subordinated, as effect, to another

as cause of its existence, but, on the contrary, is coordinated contemporaneously and reciprocally, as a cause

in relation to the determination of the others (for example, in a body the parts of which mutually attract and

repel each other). And this is an entirely different kind of connection from that which we find in the mere

relation of the cause to the effect (the principle to the consequence), for in such a connection the consequence

does not in its turn determine the principle, and therefore does not constitute, with the latter, a whole just as

the Creator does not with the world make up a whole. The process of understanding by which it represents to

itself the sphere of a divided conception, is employed also when we think of a thing as divisible; and in the

same manner as the members of the division in the former exclude one another, and yet are connected in one

sphere, so the understanding represents to itself the parts of the latter, as having each of them an existence

In the transcendental philosophy of the ancients there exists one more leading division, which contains pure

conceptions of the understanding, and which, although not numbered among the categories, ought, according

to them, as conceptions a priori, to be valid of objects. But in this case they would augment the number of the

categories; which cannot be. These are set forth in the proposition, so renowned among the schoolmen

"Quodlibet ens est UNUM, VERUM, BONUM." Now, though the inferences from this principle were mere

tautological propositions, and though it is allowed only by courtesy to retain a place in modern metaphysics,

yet a thought which maintained itself for such a length of time, however empty it seems to be, deserves an

investigation of its origin, and justifies the conjecture that it must be grounded in some law of the

understanding, which, as is often the case, has only been erroneously interpreted. These pretended

transcendental predicates are, in fact, nothing but logical requisites and criteria of all cognition of objects, and

they employ, as the basis for this cognition, the categories of quantity, namely, unity, plurality, and totality.

But these, which must be taken as material conditions, that is, as belonging to the possibility of things

themselves, they employed merely in a formal signification, as belonging to the logical requisites of all

cognition, and yet most unguardedly changed these criteria of thought into properties of objects, as things in

themselves. Now, in every cognition of an object, there is unity of conception, which may be called

qualitative unity, so far as by this term we understand only the unity in our connection of the manifold; for

example, unity of the theme in a play, an oration, or a story. Secondly, there is truth in respect of the

deductions from it. The more true deductions we have from a given conception, the more criteria of its

objective reality. This we might call the qualitative plurality of characteristic marks, which belong to a

conception as to a common foundation, but are not cogitated as a quantity in it. Thirdly, there is perfection

which consists in this, that the plurality falls back upon the unity of the conception, and accords completely

with that conception and with no other. This we may denominate qualitative completeness. Hence it is

evident that these logical criteria of the possibility of cognition are merely the three categories of quantity

modified and transformed to suit an unauthorized manner of applying them. That is to say, the three

categories, in which the unity in the production of the quantum must be homogeneous throughout, are

transformed solely with a view to the connection of heterogeneous parts of cognition in one act of

consciousness, by means of the quality of the cognition, which is the principle of that connection. Thus the

criterion of the possibility of a conception (not of its object) is the definition of it, in which the unity of the

conception, the truth of all that may be immediately deduced from it, and finally, the completeness of what

has been thus deduced, constitute the requisites for the reproduction of the whole conception. Thus also, the

criterion or test of an hypothesis is the intelligibility of the received principle of explanation, or its unity

(without help from any subsidiary hypothesis) the truth of our deductions from it (consistency with each

other and with experience) and lastly, the completeness of the principle of the explanation of these

deductions, which refer to neither more nor less than what was admitted in the hypothesis, restoring

analytically and a posteriori, what was cogitated synthetically and a priori. By the conceptions, therefore, of

unity, truth, and perfection, we have made no addition to the transcendental table of the categories, which is

complete without them. We have, on the contrary, merely employed the three categories of quantity, setting

aside their application to objects of experience, as general logical laws of the consistency of cognition with

Teachers of jurisprudence, when speaking of rights and claims, distinguish in a cause the question of right

(quid juris) from the question of fact (quid facti), and while they demand proof of both, they give to the proof

of the former, which goes to establish right or claim in law, the name of deduction. Now we make use of a

great number of empirical conceptions, without opposition from any one; and consider ourselves, even

without any attempt at deduction, justified in attaching to them a sense, and a supposititious signification,

because we have always experience at hand to demonstrate their objective reality. There exist also, however,

usurped conceptions, such as fortune, fate, which circulate with almost universal indulgence, and yet are

occasionally challenged by the question, "quid juris?" In such cases, we have great difficulty in discovering

any deduction for these terms, inasmuch as we cannot produce any manifest ground of right, either from

Among the many conceptions, which make up the very variegated web of human cognition, some are

destined for pure use a priori, independent of all experience; and their title to be so employed always requires

a deduction, inasmuch as, to justify such use of them, proofs from experience are not sufficient; but it is

necessary to know how these conceptions can apply to objects without being derived from experience. I term,

therefore, an examination of the manner in which conceptions can apply a priori to objects, the transcendental

deduction of conceptions, and I distinguish it from the empirical deduction, which indicates the mode in

which conception is obtained through experience and reflection thereon; consequently, does not concern itself

with the right, but only with the fact of our obtaining conceptions in such and such a manner. We have

already seen that we are in possession of two perfectly different kinds of conceptions, which nevertheless

agree with each other in this, that they both apply to objects completely a priori. These are the conceptions of

space and time as forms of sensibility, and the categories as pure conceptions of the understanding. To

attempt an empirical deduction of either of these classes would be labour in vain, because the distinguishing

characteristic of their nature consists in this, that they apply to their objects, without having borrowed

anything from experience towards the representation of them. Consequently, if a deduction of these

Meanwhile, with respect to these conceptions, as with respect to all our cognition, we certainly may discover

in experience, if not the principle of their possibility, yet the occasioning causes of their production. It will be

found that the impressions of sense give the first occasion for bringing into action the whole faculty of

cognition, and for the production of experience, which contains two very dissimilar elements, namely, a

matter for cognition, given by the senses, and a certain form for the arrangement of this matter, arising out of

the inner fountain of pure intuition and thought; and these, on occasion given by sensuous impressions, are

called into exercise and produce conceptions. Such an investigation into the first efforts of our faculty of

cognition to mount from particular perceptions to general conceptions is undoubtedly of great utility; and we

have to thank the celebrated Locke for having first opened the way for this inquiry. But a deduction of the

pure a priori conceptions of course never can be made in this way, seeing that, in regard to their future

employment, which must be entirely independent of experience, they must have a far different certificate of

birth to show from that of a descent from experience. This attempted physiological derivation, which cannot

properly be called deduction, because it relates merely to a quaestio facti, I shall entitle an explanation of the

possession of a pure cognition. It is therefore manifest that there can only be a transcendental deduction of

these conceptions and by no means an empirical one; also, that all attempts at an empirical deduction, in

regard to pure a priori conceptions, are vain, and can only be made by one who does not understand the

But although it is admitted that the only possible deduction of pure a priori cognition is a transcendental

deduction, it is not, for that reason, perfectly manifest that such a deduction is absolutely necessary. We have

already traced to their sources the conceptions of space and time, by means of a transcendental deduction, and

we have explained and determined their objective validity a priori. Geometry, nevertheless, advances steadily

and securely in the province of pure a priori cognitions, without needing to ask from philosophy any

certificate as to the pure and legitimate origin of its fundamental conception of space. But the use of the

conception in this science extends only to the external world of sense, the pure form of the intuition of which

is space; and in this world, therefore, all geometrical cognition, because it is founded upon a priori intuition,

possesses immediate evidence, and the objects of this cognition are given a priori (as regards their form) in

intuition by and through the cognition itself. With the pure conceptions of understanding, on the contrary,

commences the absolute necessity of seeking a transcendental deduction, not only of these conceptions

themselves, but likewise of space, because, inasmuch as they make affirmations concerning objects not by

means of the predicates of intuition and sensibility, but of pure thought a priori, they apply to objects without

any of the conditions of sensibility. Besides, not being founded on experience, they are not presented with

any object in a priori intuition upon which, antecedently to experience, they might base their synthesis. Hence

results, not only doubt as to the objective validity and proper limits of their use, but that even our conception

of space is rendered equivocal; inasmuch as we are very ready with the aid of the categories, to carry the use

of this conception beyond the conditions of sensuous intuition and, for this reason, we have already found a

transcendental deduction of it needful. The reader, then, must be quite convinced of the absolute necessity of

a transcendental deduction, before taking a single step in the field of pure reason; because otherwise he goes

to work blindly, and after he has wondered about in all directions, returns to the state of utter ignorance from

which he started. He ought, moreover, clearly to recognize beforehand the unavoidable difficulties in his

undertaking, so that he may not afterwards complain of the obscurity in which the subject itself is deeply

involved, or become too soon impatient of the obstacles in his path; because we have a choice of only two

things either at once to give up all pretensions to knowledge beyond the limits of possible experience, or to

We have been able, with very little trouble, to make it comprehensible how the conceptions of space and

time, although a priori cognitions, must necessarily apply to external objects, and render a synthetical

cognition of these possible, independently of all experience. For inasmuch as only by means of such pure

form of sensibility an object can appear to us, that is, be an object of empirical intuition, space and time are

pure intuitions, which contain a priori the condition of the possibility of objects as phenomena, and an a priori

On the other hand, the categories of the understanding do not represent the conditions under which objects

are given to us in intuition; objects can consequently appear to us without necessarily connecting themselves

with these, and consequently without any necessity binding on the understanding to contain a priori the

conditions of these objects. Thus we find ourselves involved in a difficulty which did not present itself in the

sphere of sensibility, that is to say, we cannot discover how the subjective conditions of thought can have

objective validity, in other words, can become conditions of the possibility of all cognition of objects; for

phenomena may certainly be given to us in intuition without any help from the functions of the

understanding. Let us take, for example, the conception of cause, which indicates a peculiar kind of synthesis,

namely, that with something, A, something entirely different, B, is connected according to a law. It is not a

priori manifest why phenomena should contain anything of this kind (we are of course debarred from

appealing for proof to experience, for the objective validity of this conception must be demonstrated a priori),

and it hence remains doubtful a priori, whether such a conception be not quite void and without any

corresponding object among phenomena. For that objects of sensuous intuition must correspond to the formal

conditions of sensibility existing a priori in the mind is quite evident, from the fact that without these they

could not be objects for us; but that they must also correspond to the conditions which understanding requires

for the synthetical unity of thought is an assertion, the grounds for which are not so easily to be discovered.

For phenomena might be so constituted as not to correspond to the conditions of the unity of thought; and all

things might lie in such confusion that, for example, nothing could be met with in the sphere of phenomena to

suggest a law of synthesis, and so correspond to the conception of cause and effect; so that this conception

would be quite void, null, and without significance. Phenomena would nevertheless continue to present

objects to our intuition; for mere intuition does not in any respect stand in need of the functions of thought.

If we thought to free ourselves from the labour of these investigations by saying: "Experience is constantly

offering us examples of the relation of cause and effect in phenomena, and presents us with abundant

opportunity of abstracting the conception of cause, and so at the same time of corroborating the objective

validity of this conception"; we should in this case be overlooking the fact, that the conception of cause

cannot arise in this way at all; that, on the contrary, it must either have an a priori basis in the, understanding,

or be rejected as a mere chimera. For this conception demands that something, A, should be of such a nature

that something else, B, should follow from it necessarily, and according to an absolutely universal law. We

may certainly collect from phenomena a law, according to which this or that usually happens, but the element

of necessity is not to be found in it. Hence it is evident that to the synthesis of cause and effect belongs a

dignity, which is utterly wanting in any empirical synthesis; for it is no mere mechanical synthesis, by means

of addition, but a dynamical one; that is to say, the effect is not to be cogitated as merely annexed to the

cause, but as posited by and through the cause, and resulting from it. The strict universality of this law never

can be a characteristic of empirical laws, which obtain through induction only a comparative universality, that

is, an extended range of practical application. But the pure conceptions of the understanding would entirely

lose all their peculiar character, if we treated them merely as the productions of experience.

There are only two possible ways in which synthetical representation and its objects can coincide with and

relate necessarily to each other, and, as it were, meet together. Either the object alone makes the

representation possible, or the representation alone makes the object possible. In the former case, the relation

between them is only empirical, and an a priori representation is impossible. And this is the case with

phenomena, as regards that in them which is referable to mere sensation. In the latter case although

representation alone (for of its causality, by means of the will, we do not here speak) does not produce the

object as to its existence, it must nevertheless be a priori determinative in regard to the object, if it is only by

means of the representation that we can cognize anything as an object. Now there are only two conditions of

the possibility of a cognition of objects; firstly, intuition, by means of which the object, though only as

phenomenon, is given; secondly, conception, by means of which the object which corresponds to this

intuition is thought. But it is evident from what has been said on aesthetic that the first condition, under

which alone objects can be intuited, must in fact exist, as a formal basis for them, a priori in the mind. With

this formal condition of sensibility, therefore, all phenomena necessarily correspond, because it is only

through it that they can be phenomena at all; that is, can be empirically intuited and given. Now the question

is whether there do not exist, a priori in the mind, conceptions of understanding also, as conditions under

which alone something, if not intuited, is yet thought as object. If this question be answered in the

affirmative, it follows that all empirical cognition of objects is necessarily conformable to such conceptions,

since, if they are not presupposed, it is impossible that anything can be an object of experience. Now all

experience contains, besides the intuition of the senses through which an object is given, a conception also of

an object that is given in intuition. Accordingly, conceptions of objects in general must lie as a priori

conditions at the foundation of all empirical cognition; and consequently, the objective validity of the

categories, as a priori conceptions, will rest upon this, that experience (as far as regards the form of thought)

is possible only by their means. For in that case they apply necessarily and a priori to objects of experience,

The whole aim of the transcendental deduction of all a priori conceptions is to show that these conceptions

are a priori conditions of the possibility of all experience. Conceptions which afford us the objective

foundation of the possibility of experience are for that very reason necessary. But the analysis of the

experiences in which they are met with is not deduction, but only an illustration of them, because from

experience they could never derive the attribute of necessity. Without their original applicability and relation

to all possible experience, in which all objects of cognition present themselves, the relation of the categories

The celebrated Locke, for want of due reflection on these points, and because he met with pure conceptions

of the understanding in experience, sought also to deduce them from experience, and yet proceeded so

inconsequently as to attempt, with their aid, to arrive it cognitions which lie far beyond the limits of all

experience. David Hume perceived that, to render this possible, it was necessary that the conceptions should

have an a priori origin. But as he could not explain how it was possible that conceptions which are not

connected with each other in the understanding must nevertheless be thought as necessarily connected in the

object and it never occurred to him that the understanding itself might, perhaps, by means of these

conceptions, be the author of the experience in which its objects were presented to it he was forced to drive

these conceptions from experience, that is, from a subjective necessity arising from repeated association of

experiences erroneously considered to be objective in one word, from habit. But he proceeded with perfect

consequence and declared it to be impossible, with such conceptions and the principles arising from them, to

overstep the limits of experience. The empirical derivation, however, which both of these philosophers

attributed to these conceptions, cannot possibly be reconciled with the fact that we do possess scientific a

The former of these two celebrated men opened a wide door to extravagance (for if reason has once

undoubted right on its side, it will not allow itself to be confined to set limits, by vague recommendations of

moderation); the latter gave himself up entirely to scepticism a natural consequence, after having

discovered, as he thought, that the faculty of cognition was not trustworthy. We now intend to make a trial

whether it be not possible safely to conduct reason between these two rocks, to assign her determinate limits,

I shall merely premise an explanation of what the categories are. They are conceptions of an object in

general, by means of which its intuition is contemplated as determined in relation to one of the logical

functions of judgement. The following will make this plain. The function of the categorical judgement is that

of the relation of subject to predicate; for example, in the proposition: "All bodies are divisible." But in

regard to the merely logical use of the understanding, it still remains undetermined to which Of these two

conceptions belongs the function Of subject and to which that of predicate. For we could also say: "Some

divisible is a body." But the category of substance, when the conception of a body is brought under it,

determines that; and its empirical intuition in experience must be contemplated always as subject and never

The manifold content in our representations can be given in an intuition which is merely sensuous in other

words, is nothing but susceptibility; and the form of this intuition can exist a priori in our faculty of

representation, without being anything else but the mode in which the subject is affected. But the conjunction

(conjunctio) of a manifold in intuition never can be given us by the senses; it cannot therefore be contained in

the pure form of sensuous intuition, for it is a spontaneous act of the faculty of representation. And as we

must, to distinguish it from sensibility, entitle this faculty understanding; so all conjunction whether

conscious or unconscious, be it of the manifold in intuition, sensuous or nonsensuous, or of several

conceptions is an act of the understanding. To this act we shall give the general appellation of synthesis,

thereby to indicate, at the same time, that we cannot represent anything as conjoined in the object without

having previously conjoined it ourselves. Of all mental notions, that of conjunction is the only one which

cannot be given through objects, but can be originated only by the subject itself, because it is an act of its

purely spontaneous activity. The reader will easily enough perceive that the possibility of conjunction must

be grounded in the very nature of this act, and that it must be equally valid for all conjunction, and that

analysis, which appears to be its contrary, must, nevertheless, always presuppose it; for where the

understanding has not previously conjoined, it cannot dissect or analyse, because only as conjoined by it,

must that which is to be analysed have been given to our faculty of representation.

But the conception of conjunction includes, besides the conception of the manifold and of the synthesis of it,

that of the unity of it also. Conjunction is the representation of the synthetical unity of the manifold.* This

idea of unity, therefore, cannot arise out of that of conjunction; much rather does that idea, by combining

itself with the representation of the manifold, render the conception of conjunction possible. This unity,

which a priori precedes all conceptions of conjunction, is not the category of unity (SS 6); for all the

categories are based upon logical functions of judgement, and in these functions we already have conjunction,

and consequently unity of given conceptions. It is therefore evident that the category of unity presupposes

conjunction. We must therefore look still higher for this unity (as qualitative, SS 8), in that, namely, which

contains the ground of the unity of diverse conceptions in judgements, the ground, consequently, of the

possibility of the existence of the understanding, even in regard to its logical use.

*Whether the representations are in themselves identical, and consequently whether one can be thought

analytically by means of and through the other, is a question which we need not at present consider. Our

Consciousness of the one, when we speak of the manifold, is always distinguishable from our consciousness

of the other; and it is only respecting the synthesis of this (possible) consciousness that we here treat.

The "I think" must accompany all my representations, for otherwise something would be represented in me

which could not be thought; in other words, the representation would either be impossible, or at least be, in

relation to me, nothing. That representation which can be given previously to all thought is called intuition.

All the diversity or manifold content of intuition, has, therefore, a necessary relation to the 'I think," in the

subject in which this diversity is found. But this representation, "I think," is an act of spontaneity; that is to

say, it cannot be regarded as belonging to mere sensibility. I call it pure apperception, in order to distinguish

it from empirical; or primitive apperception, because it is selfconsciousness which, whilst it gives birth to

the representation" I think," must necessarily be capable of accompanying all our representations. It is in all

acts of consciousness one and the same, and unaccompanied by it, no representation can exist for me. The

SECTION II Transcendental Deduction of the pure Conceptions of the Understanding. 53

unity of this apperception I call the transcendental unity of selfconsciousness, in order to indicate the

possibility of a priori cognition arising from it. For the manifold representations which are given in an

intuition would not all of them be my representations, if they did not all belong to one selfconsciousness,

that is, as my representations (even although I am not conscious of them as such), they must conform to the

condition under which alone they can exist together in a common selfconsciousness, because otherwise they

would not all without exception belong to me. From this primitive conjunction follow many important

For example, this universal identity of the apperception of the manifold given in intuition contains a synthesis

of representations and is possible only by means of the consciousness of this synthesis. For the empirical

consciousness which accompanies different representations is in itself fragmentary and disunited, and without

relation to the identity of the subject. This relation, then, does not exist because I accompany every

representation with consciousness, but because I join one representation to another, and am conscious of the

synthesis of them. Consequently, only because I can connect a variety of given representations in one

consciousness, is it possible that I can represent to myself the identity of consciousness in these

representations; in other words, the analytical unity of apperception is possible only under the presupposition

of a synthetical unity.* The thought, "These representations given in intuition belong all of them to me," is

accordingly just the same as, "I unite them in one selfconsciousness, or can at least so unite them"; and

although this thought is not itself the consciousness of the synthesis of representations, it presupposes the

possibility of it; that is to say, for the reason alone that I can comprehend the variety of my representations in

one consciousness, do I call them my representations, for otherwise I must have as manycoloured and

various a self as are the representations of which I am conscious. Synthetical unity of the manifold in

intuitions, as given a priori, is therefore the foundation of the identity of apperception itself, which antecedes

a priori all determinate thought. But the conjunction of representations into a conception is not to be found in

objects themselves, nor can it be, as it were, borrowed from them and taken up into the understanding by

perception, but it is on the contrary an operation of the understanding itself, which is nothing more than the

faculty of conjoining a priori and of bringing the variety of given representations under the unity of

*All general conceptions as such depend, for their existence, on the analytical unity of consciousness. For

example, when I think of red in general, I thereby think to myself a property which (as a characteristic mark)

can be discovered somewhere, or can be united with other representations; consequently, it is only by means

of a forethought possible synthetical unity that I can think to myself the analytical. A representation which is

cogitated as common to different representations, is regarded as belonging to such as, besides this common

representation, contain something different; consequently it must be previously thought in synthetical unity

with other although only possible representations, before I can think in it the analytical unity of

consciousness which makes it a conceptas communis. And thus the synthetical unity of apperception is the

highest point with which we must connect every operation of the understanding, even the whole of logic, and

after it our transcendental philosophy; indeed, this faculty is the understanding itself.

This fundamental principle of the necessary unity of apperception is indeed an identical, and therefore

analytical, proposition; but it nevertheless explains the necessity for a synthesis of the manifold given in an

intuition, without which the identity of selfconsciousness would be incogitable. For the ego, as a simple

representation, presents us with no manifold content; only in intuition, which is quite different from the

representation ego, can it be given us, and by means of conjunction it is cogitated in one selfconsciousness.

An understanding, in which all the manifold should be given by means of consciousness itself, would be

intuitive; our understanding can only think and must look for its intuition to sense. I am, therefore, conscious

of my identical self, in relation to all the variety of representations given to me in an intuition, because I call

all of them my representations. In other words, I am conscious myself of a necessary a priori synthesis of my

representations, which is called the original synthetical unity of apperception, under which rank all the

SECTION II Transcendental Deduction of the pure Conceptions of the Understanding. 54

The supreme principle of the possibility of all intuition in relation to sensibility was, according to our

transcendental aesthetic, that all the manifold in intuition be subject to the formal conditions of space and

time. The supreme principle of the possibility of it in relation to the understanding is that all the manifold in it

be subject to conditions of the originally synthetical unity or apperception.* To the former of these two

principles are subject all the various representations of intuition, in so far as they are given to us; to the latter,

in so far as they must be capable of conjunction in one consciousness; for without this nothing can be thought

or cognized, because the given representations would not have in common the act Of the apperception "I

*Space and time, and all portions thereof, are intuitions; consequently are, with a manifold for their content,

single representations. (See the Transcendental Aesthetic.) Consequently, they are not pure conceptions, by

means of which the same consciousness is found in a great number of representations; but, on the contrary,

they are many representations contained in one, the consciousness of which is, so to speak, compounded. The

unity of consciousness is nevertheless synthetical and, therefore, primitive. From this peculiar character of

Understanding is, to speak generally, the faculty Of cognitions. These consist in the determined relation of

given representation to an object. But an object is that, in the conception of which the manifold in a given

intuition is united. Now all union of representations requires unity of consciousness in the synthesis of them.

Consequently, it is the unity of consciousness alone that constitutes the possibility of representations relating

to an object, and therefore of their objective validity, and of their becoming cognitions, and consequently, the

The first pure cognition of understanding, then, upon which is founded all its other exercise, and which is at

the same time perfectly independent of all conditions of mere sensuous intuition, is the principle of the

original synthetical unity of apperception. Thus the mere form of external sensuous intuition, namely, space,

affords us, per se, no cognition; it merely contributes the manifold in a priori intuition to a possible cognition.

But, in order to cognize something in space (for example, a line), I must draw it, and thus produce

synthetically a determined conjunction of the given manifold, so that the unity of this act is at the same time

the unity of consciousness (in the conception of a line), and by this means alone is an object (a determinate

space) cognized. The synthetical unity of consciousness is, therefore, an objective condition of all cognition,

which I do not merely require in order to cognize an object, but to which every intuition must necessarily be

subject, in order to become an object for me; because in any other way, and without this synthesis, the

This proposition is, as already said, itself analytical, although it constitutes the synthetical unity, the condition

of all thought; for it states nothing more than that all my representations in any given intuition must be

subject to the condition which alone enables me to connect them, as my representation with the identical self,

and so to unite them synthetically in one apperception, by means of the general expression, "I think."

But this principle is not to be regarded as a principle for every possible understanding, but only for the

understanding by means of whose pure apperception in the thought I am, no manifold content is given. The

understanding or mind which contained the manifold in intuition, in and through the act itself of its own

selfconsciousness, in other words, an understanding by and in the representation of which the objects of the

representation should at the same time exist, would not require a special act of synthesis of the manifold as

the condition of the unity of its consciousness, an act of which the human understanding, which thinks only

and cannot intuite, has absolute need. But this principle is the first principle of all the operations of our

The Principle of the Synthetical Unity of Apperception is the highest Principle of all exercise of the Understanding. SS 13 55

understanding, so that we cannot form the least conception of any other possible understanding, either of one

such as should be itself intuition, or possess a sensuous intuition, but with forms different from those of space

It is by means of the transcendental unity of apperception that all the manifold, given in an intuition is united

into a conception of the object. On this account it is called objective, and must be distinguished from the

subjective unity of consciousness, which is a determination of the internal sense, by means of which the said

manifold in intuition is given empirically to be so united. Whether I can be empirically conscious of the

manifold as coexistent or as successive, depends upon circumstances, or empirical conditions. Hence the

empirical unity of consciousness by means of association of representations, itself relates to a phenomenal

world and is wholly contingent. On the contrary, the pure form of intuition in time, merely as an intuition,

which contains a given manifold, is subject to the original unity of consciousness, and that solely by means of

the necessary relation of the manifold in intuition to the "I think," consequently by means of the pure

synthesis of the understanding, which lies a priori at the foundation of all empirical synthesis. The

transcendental unity of apperception is alone objectively valid; the empirical which we do not consider in this

essay, and which is merely a unity deduced from the former under given conditions in concreto, possesses

only subjective validity. One person connects the notion conveyed in a word with one thing, another with

another thing; and the unity of consciousness in that which is empirical, is, in relation to that which is given

I could never satisfy myself with the definition which logicians give of a judgement. It is, according to them,

the representation of a relation between two conceptions. I shall not dwell here on the faultiness of this

definition, in that it suits only for categorical and not for hypothetical or disjunctive judgements, these latter

containing a relation not of conceptions but of judgements themselves a blunder from which many evil

results have followed.* It is more important for our present purpose to observe, that this definition does not

*The tedious doctrine of the four syllogistic figures concerns only categorical syllogisms; and although it is

nothing more than an artifice by surreptitiously introducing immediate conclusions (consequentiae

immediatae) among the premises of a pure syllogism, to give ism' give rise to an appearance of more modes

of drawing a conclusion than that in the first figure, the artifice would not have had much success, had not its

authors succeeded in bringing categorical judgements into exclusive respect, as those to which all others must

But if I investigate more closely the relation of given cognitions in every judgement, and distinguish it, as

belonging to the understanding, from the relation which is produced according to laws of the reproductive

imagination (which has only subjective validity), I find that judgement is nothing but the mode of bringing

given cognitions under the objective unit of apperception. This is plain from our use of the term of relation is

in judgements, in order to distinguish the objective unity of given representations from the subjective unity.

For this term indicates the relation of these representations to the original apperception, and also their

necessary unity, even although the judgement is empirical, therefore contingent, as in the judgement: "All

bodies are heavy." I do not mean by this, that these representations do necessarily belong to each other in

empirical intuition, but that by means of the necessary unity of appreciation they belong to each other in the

synthesis of intuitions, that is to say, they belong to each other according to principles of the objective

determination of all our representations, in so far as cognition can arise from them, these principles being all

deduced from the main principle of the transcendental unity of apperception. In this way alone can there arise

from this relation a judgement, that is, a relation which has objective validity, and is perfectly distinct from

that relation of the very same representations which has only subjective validity a relation, to wit, which is

produced according to laws of association. According to these laws, I could only say: "When I hold in my

hand or carry a body, I feel an impression of weight"; but I could not say: "It, the body, is heavy"; for this is

tantamount to saying both these representations are conjoined in the object, that is, without distinction as to

the condition of the subject, and do not merely stand together in my perception, however frequently the

The manifold content given in a sensuous intuition comes necessarily under the original synthetical unity of

apperception, because thereby alone is the unity of intuition possible (SS 13). But that act of the

understanding, by which the manifold content of given representations (whether intuitions or conceptions) is

brought under one apperception, is the logical function of judgements (SS 15). All the manifold, therefore, in

so far as it is given in one empirical intuition, is determined in relation to one of the logical functions of

judgement, by means of which it is brought into union in one consciousness. Now the categories are nothing

else than these functions of judgement so far as the manifold in a given intuition is determined in relation to

them (SS 9). Consequently, the manifold in a given intuition is necessarily subject to the categories of the

The manifold in an intuition, which I call mine, is represented by means of the synthesis of the

understanding, as belonging to the necessary unity of selfconsciousness, and this takes place by means of

the category.* The category indicates accordingly that the empirical consciousness of a given manifold in an

intuition is subject to a pure selfconsciousness a priori, in the same manner as an empirical intuition is

subject to a pure sensuous intuition, which is also a priori. In the above proposition, then, lies the beginning

of a deduction of the pure conceptions of the understanding. Now, as the categories have their origin in the

understanding alone, independently of sensibility, I must in my deduction make abstraction of the mode in

which the manifold of an empirical intuition is given, in order to fix my attention exclusively on the unity

which is brought by the understanding into the intuition by means of the category. In what follows (SS 22), it

will be shown, from the mode in which the empirical intuition is given in the faculty of sensibility, that the

unity which belongs to it is no other than that which the category (according to SS 16) imposes on the

manifold in a given intuition, and thus, its a priori validity in regard to all objects of sense being established,

*The proof of this rests on the represented unity of intuition, by means of which an object is given, and which

always includes in itself a synthesis of the manifold to be intuited, and also the relation of this latter to unity

But there is one thing in the above demonstration of which I could not make abstraction, namely, that the

manifold to be intuited must be given previously to the synthesis of the understanding, and independently of

it. How this takes place remains here undetermined. For if I cogitate an understanding which was itself

intuitive (as, for example, a divine understanding which should not represent given objects, but by whose

representation the objects themselves should be given or produced), the categories would possess no

significance in relation to such a faculty of cognition. They are merely rules for an understanding, whose

whole power consists in thought, that is, in the act of submitting the synthesis of the manifold which is

All Sensuous Intuitions are subject to the Categories, as Conditions under which alone the manifold Content of them can be united in one Consciousness. SS 16 57

presented to it in intuition from a very different quarter, to the unity of apperception; a faculty, therefore,

which cognizes nothing per se, but only connects and arranges the material of cognition, the intuition,

namely, which must be presented to it by means of the object. But to show reasons for this peculiar character

of our understandings, that it produces unity of apperception a priori only by means of categories, and a

certain kind and number thereof, is as impossible as to explain why we are endowed with precisely so many

functions of judgement and no more, or why time and space are the only forms of our intuition.

To think an object and to cognize an object are by no means the same thing. In cognition there are two

elements: firstly, the conception, whereby an object is cogitated (the category); and, secondly, the intuition,

whereby the object is given. For supposing that to the conception a corresponding intuition could not be

given, it would still be a thought as regards its form, but without any object, and no cognition of anything

would be possible by means of it, inasmuch as, so far as I knew, there existed and could exist nothing to

which my thought could be applied. Now all intuition possible to us is sensuous; consequently, our thought of

an object by means of a pure conception of the understanding, can become cognition for us only in so far as

this conception is applied to objects of the senses. Sensuous intuition is either pure intuition (space and time)

or empirical intuition of that which is immediately represented in space and time by means of sensation as

real. Through the determination of pure intuition we obtain a priori cognitions of objects, as in mathematics,

but only as regards their form as phenomena; whether there can exist things which must be intuited in this

form is not thereby established. All mathematical conceptions, therefore, are not per se cognition, except in

so far as we presuppose that there exist things which can only be represented conformably to the form of our

pure sensuous intuition. But things in space and time are given only in so far as they are perceptions

(representations accompanied with sensation), therefore only by empirical representation. Consequently the

pure conceptions of the understanding, even when they are applied to intuitions a priori (as in mathematics),

produce cognition only in so far as these (and therefore the conceptions of the understanding by means of

them) can be applied to empirical intuitions. Consequently the categories do not, even by means of pure

intuition afford us any cognition of things; they can only do so in so far as they can be applied to empirical

intuition. That is to say, the, categories serve only to render empirical cognition possible. But this is what we

call experience. Consequently, in cognition, their application to objects of experience is the only legitimate

The foregoing proposition is of the utmost importance, for it determines the limits of the exercise of the pure

conceptions of the understanding in regard to objects, just as transcendental aesthetic determined the limits of

the exercise of the pure form of our sensuous intuition. Space and time, as conditions of the possibility of the

presentation of objects to us, are valid no further than for objects of sense, consequently, only for experience.

Beyond these limits they represent to us nothing, for they belong only to sense, and have no reality apart from

it. The pure conceptions of the understanding are free from this limitation, and extend to objects of intuition

in general, be the intuition like or unlike to ours, provided only it be sensuous, and not intellectual. But this

extension of conceptions beyond the range of our intuition is of no advantage; for they are then mere empty

conceptions of objects, as to the possibility or impossibility of the existence of which they furnish us with no

means of discovery. They are mere forms of thought, without objective reality, because we have no intuition

to which the synthetical unity of apperception, which alone the categories contain, could be applied, for the

purpose of determining an object. Our sensuous and empirical intuition can alone give them significance and

In Cognition, its Application to Objects of Experience is the only legitimate use of the Category. SS 18 58

If, then, we suppose an object of a nonsensuous intuition to be given we can in that case represent it by all

those predicates which are implied in the presupposition that nothing appertaining to sensuous intuition

belongs to it; for example, that it is not extended, or in space; that its duration is not time; that in it no change

(the effect of the determinations in time) is to be met with, and so on. But it is no proper knowledge if I

merely indicate what the intuition of the object is not, without being able to say what is contained in it, for I

have not shown the possibility of an object to which my pure conception of understanding could be

applicable, because I have not been able to furnish any intuition corresponding to it, but am only able to say

that our intuition is not valid for it. But the most important point is this, that to a something of this kind not

one category can be found applicable. Take, for example, the conception of substance, that is, something that

can exist as subject, but never as mere predicate; in regard to this conception I am quite ignorant whether

there can really be anything to correspond to such a determination of thought, if empirical intuition did not

The pure conceptions of the understanding apply to objects of intuition in general, through the understanding

alone, whether the intuition be our own or some other, provided only it be sensuous, but are, for this very

reason, mere forms of thought, by means of which alone no determined object can be cognized. The synthesis

or conjunction of the manifold in these conceptions relates, we have said, only to the unity of apperception,

and is for this reason the ground of the possibility of a priori cognition, in so far as this cognition is dependent

on the understanding. This synthesis is, therefore, not merely transcendental, but also purely intellectual. But

because a certain form of sensuous intuition exists in the mind a priori which rests on the receptivity of the

representative faculty (sensibility), the understanding, as a spontaneity, is able to determine the internal sense

by means of the diversity of given representations, conformably to the synthetical unity of apperception, and

thus to cogitate the synthetical unity of the apperception of the manifold of sensuous intuition a priori, as the

condition to which must necessarily be submitted all objects of human intuition. And in this manner the

categories as mere forms of thought receive objective reality, that is, application to objects which are given to

us in intuition, but that only as phenomena, for it is only of phenomena that we are capable of a priori

This synthesis of the manifold of sensuous intuition, which is possible and necessary a priori, may be called

figurative (synthesis speciosa), in contradistinction to that which is cogitated in the mere category in regard to

the manifold of an intuition in general, and is called connection or conjunction of the understanding

(synthesis intellectualis). Both are transcendental, not merely because they themselves precede a priori all

experience, but also because they form the basis for the possibility of other cognition a priori.

But the figurative synthesis, when it has relation only to the originally synthetical unity of apperception, that

is to the transcendental unity cogitated in the categories, must, to be distinguished from the purely intellectual

conjunction, be entitled the transcendental synthesis of imagination. Imagination is the faculty of representing

an object even without its presence in intuition. Now, as all our intuition is sensuous, imagination, by reason

of the subjective condition under which alone it can give a corresponding intuition to the conceptions of the

understanding, belongs to sensibility. But in so far as the synthesis of the imagination is an act of spontaneity,

which is determinative, and not, like sense, merely determinable, and which is consequently able to determine

sense a priori, according to its form, conformably to the unity of apperception, in so far is the imagination a

faculty of determining sensibility a priori, and its synthesis of intuitions according to the categories must be

the transcendental synthesis of the imagination. It is an operation of the understanding on sensibility, and the

first application of the understanding to objects of possible intuition, and at the same time the basis for the

exercise of the other functions of that faculty. As figurative, it is distinguished from the merely intellectual

synthesis, which is produced by the understanding alone, without the aid of imagination. Now, in so far as

Of the Application of the Categories to Objects of the Senses in general. SS 20 59

imagination is spontaneity, I sometimes call it also the productive imagination, and distinguish it from the

reproductive, the synthesis of which is subject entirely to empirical laws, those of association, namely, and

which, therefore, contributes nothing to the explanation of the possibility of a priori cognition, and for this

We have now arrived at the proper place for explaining the paradox which must have struck every one in our

exposition of the internal sense (SS 6), namely how this sense represents us to our own consciousness, only

as we appear to ourselves, not as we are in ourselves, because, to wit, we intuite ourselves only as we are

inwardly affected. Now this appears to be contradictory, inasmuch as we thus stand in a passive relation to

ourselves; and therefore in the systems of psychology, the internal sense is commonly held to be one with the

That which determines the internal sense is the understanding, and its original power of conjoining the

manifold of intuition, that is, of bringing this under an apperception (upon which rests the possibility of the

understanding itself). Now, as the human understanding is not in itself a faculty of intuition, and is unable to

exercise such a power, in order to conjoin, as it were, the manifold of its own intuition, the synthesis of

understanding is, considered per se, nothing but the unity of action, of which, as such, it is selfconscious,

even apart from sensibility, by which, moreover, it is able to determine our internal sense in respect of the

manifold which may be presented to it according to the form of sensuous intuition. Thus, under the name of a

transcendental synthesis of imagination, the understanding exercises an activity upon the passive subject,

whose faculty it is; and so we are right in saying that the internal sense is affected thereby. Apperception and

its synthetical unity are by no means one and the same with the internal sense. The former, as the source of all

our synthetical conjunction, applies, under the name of the categories, to the manifold of intuition in general,

prior to all sensuous intuition of objects. The internal sense, on the contrary, contains merely the form of

intuition, but without any synthetical conjunction of the manifold therein, and consequently does not contain

any determined intuition, which is possible only through consciousness of the determination of the manifold

by the transcendental act of the imagination (synthetical influence of the understanding on the internal sense),

This we can indeed always perceive in ourselves. We cannot cogitate a geometrical line without drawing it in

thought, nor a circle without describing it, nor represent the three dimensions of space without drawing three

lines from the same point perpendicular to one another. We cannot even cogitate time, unless, in drawing a

straight line (which is to serve as the external figurative representation of time), we fix our attention on the

act of the synthesis of the manifold, whereby we determine successively the internal sense, and thus attend

also to the succession of this determination. Motion as an act of the subject (not as a determination of an

object),* consequently the synthesis of the manifold in space, if we make abstraction of space and attend

merely to the act by which we determine the internal sense according to its form, is that which produces the

conception of succession. The understanding, therefore, does by no means find in the internal sense any such

synthesis of the manifold, but produces it, in that it affects this sense. At the same time, how "I who think" is

distinct from the "I" which intuites itself (other modes of intuition being cogitable as at least possible), and

yet one and the same with this latter as the same subject; how, therefore, I am able to say: "I, as an

intelligence and thinking subject, cognize myself as an object thought, so far as I am, moreover, given to

myself in intuition only, like other phenomena, not as I am in myself, and as considered by the

understanding, but merely as I appear" is a question that has in it neither more nor less difficulty than the

question "How can I be an object to myself?" or this "How I can be an object of my own intuition and

internal perceptions?" But that such must be the fact, if we admit that space is merely a pure form of the

phenomena of external sense, can be clearly proved by the consideration that we cannot represent time, which

is not an object of external intuition, in any other way than under the image of a line, which we draw in

thought, a mode of representation without which we could not cognize the unity of its dimension, and also

that we are necessitated to take our determination of periods of time, or of points of time, for all our internal

perceptions from the changes which we perceive in outward things. It follows that we must arrange the

Of the Application of the Categories to Objects of the Senses in general. SS 20 60

determinations of the internal sense, as phenomena in time, exactly in the same manner as we arrange those

of the external senses in space. And consequently, if we grant, respecting this latter, that by means of them

we know objects only in so far as we are affected externally, we must also confess, with regard to the internal

sense, that by means of it we intuite ourselves only as we are internally affected by ourselves; in other words,

as regards internal intuition, we cognize our own subject only as phenomenon, and not as it is in itself.*[2]

*Motion of an object in space does not belong to a pure science, consequently not to geometry; because, that

a thing is movable cannot be known a priori, but only from experience. But motion, considered as the

description of a space, is a pure act of the successive synthesis of the manifold in external intuition by means

of productive imagination, and belongs not only to geometry, but even to transcendental philosophy.

*[2] I do not see why so much difficulty should be found in admitting that our internal sense is affected by

ourselves. Every act of attention exemplifies it. In such an act the understanding determines the internal sense

by the synthetical conjunction which it cogitates, conformably to the internal intuition which corresponds to

the manifold in the synthesis of the understanding. How much the mind is usually affected thereby every one

On the other hand, in the transcendental synthesis of the manifold content of representations, consequently in

the synthetical unity of apperception, I am conscious of myself, not as I appear to myself, nor as I am in

myself, but only that "I am." This representation is a thought, not an intuition. Now, as in order to cognize

ourselves, in addition to the act of thinking, which subjects the manifold of every possible intuition to the

unity of apperception, there is necessary a determinate mode of intuition, whereby this manifold is given;

although my own existence is certainly not mere phenomenon (much less mere illusion), the determination of

my existence* Can only take place conformably to the form of the internal sense, according to the particular

mode in which the manifold which I conjoin is given in internal intuition, and I have therefore no knowledge

of myself as I am, but merely as I appear to myself. The consciousness of self is thus very far from a

knowledge of self, in which I do not use the categories, whereby I cogitate an object, by means of the

conjunction of the manifold in one apperception. In the same way as I require, for the sake of the cognition of

an object distinct from myself, not only the thought of an object in general (in the category), but also an

intuition by which to determine that general conception, in the same way do I require, in order to the

cognition of myself, not only the consciousness of myself or the thought that I think myself, but in addition

an intuition of the manifold in myself, by which to determine this thought. It is true that I exist as an

intelligence which is conscious only of its faculty of conjunction or synthesis, but subjected in relation to the

manifold which this intelligence has to conjoin to a limitative conjunction called the internal sense. My

intelligence (that is, I) can render that conjunction or synthesis perceptible only according to the relations of

time, which are quite beyond the proper sphere of the conceptions of the understanding and consequently

cognize itself in respect to an intuition (which cannot possibly be intellectual, nor given by the

understanding), only as it appears to itself, and not as it would cognize itself, if its intuition were intellectual.

*The "I think" expresses the act of determining my own existence. My existence is thus already given by the

act of consciousness; but the mode in which I must determine my existence, that is, the mode in which I must

place the manifold belonging to my existence, is not thereby given. For this purpose intuition of self is

required, and this intuition possesses a form given a priori, namely, time, which is sensuous, and belongs to

our receptivity of the determinable. Now, as I do not possess another intuition of self which gives the

determining in me (of the spontaneity of which I am conscious), prior to the act of determination, in the same

manner as time gives the determinable, it is clear that I am unable to determine my own existence as that of a

spontaneous being, but I am only able to represent to myself the spontaneity of my thought, that is, of my

determination, and my existence remains ever determinable in a purely sensuous manner, that is to say, like

the existence of a phenomenon. But it is because of this spontaneity that I call myself an intelligence.

In the metaphysical deduction, the a priori origin of categories was proved by their complete accordance with

the general logical of thought; in the transcendental deduction was exhibited the possibility of the categories

as a priori cognitions of objects of an intuition in general (SS 16 and 17).At present we are about to explain

the possibility of cognizing, a priori, by means of the categories, all objects which can possibly be presented

to our senses, not, indeed, according to the form of their intuition, but according to the laws of their

conjunction or synthesis, and thus, as it were, of prescribing laws to nature and even of rendering nature

possible. For if the categories were inadequate to this task, it would not be evident to us why everything that

is presented to our senses must be subject to those laws which have an a priori origin in the understanding

I premise that by the term synthesis of apprehension I understand the combination of the manifold in an

empirical intuition, whereby perception, that is, empirical consciousness of the intuition (as phenomenon), is

We have a priori forms of the external and internal sensuous intuition in the representations of space and

time, and to these must the synthesis of apprehension of the manifold in a phenomenon be always

comformable, because the synthesis itself can only take place according to these forms. But space and time

are not merely forms of sensuous intuition, but intuitions themselves (which contain a manifold), and

therefore contain a priori the determination of the unity of this manifold.* (See the Transcendent Aesthetic.)

Therefore is unity of the synthesis of the manifold without or within us, consequently also a conjunction to

which all that is to be represented as determined in space or time must correspond, given a priori along with

(not in) these intuitions, as the condition of the synthesis of all apprehension of them. But this synthetical

unity can be no other than that of the conjunction of the manifold of a given intuition in general, in a

primitive act of consciousness, according to the categories, but applied to our sensuous intuition.

Consequently all synthesis, whereby alone is even perception possible, is subject to the categories. And, as

experience is cognition by means of conjoined perceptions, the categories are conditions of the possibility of

*Space represented as an object (as geometry really requires it to be) contains more than the mere form of the

intuition; namely, a combination of the manifold given according to the form of sensibility into a

representation that can be intuited; so that the form of the intuition gives us merely the manifold, but the

formal intuition gives unity of representation. In the aesthetic, I regarded this unity as belonging entirely to

sensibility, for the purpose of indicating that it antecedes all conceptions, although it presupposes a synthesis

which does not belong to sense, through which alone, however, all our conceptions of space and time are

possible. For as by means of this unity alone (the understanding determining the sensibility) space and time

are given as intuitions, it follows that the unity of this intuition a priori belongs to space and time, and not to

When, then, for example, I make the empirical intuition of a house by apprehension of the manifold

contained therein into a perception, the necessary unity of space and of my external sensuous intuition lies at

the foundation of this act, and I, as it were, draw the form of the house conformably to this synthetical unity

of the manifold in space. But this very synthetical unity remains, even when I abstract the form of space, and

has its seat in the understanding, and is in fact the category of the synthesis of the homogeneous in an

intuition; that is to say, the category of quantity, to which the aforesaid synthesis of apprehension, that is, the

*In this manner it is proved, that the synthesis of apprehension, which is empirical, must necessarily be

conformable to the synthesis of apperception, which is intellectual, and contained a priori in the category. It is

one and the same spontaneity which at one time, under the name of imagination, at another under that of

To take another example, when I perceive the freezing of water, I apprehend two states (fluidity and solidity),

which, as such, stand toward each other mutually in a relation of time. But in the time, which I place as an

internal intuition, at the foundation of this phenomenon, I represent to myself synthetical unity of the

manifold, without which the aforesaid relation could not be given in an intuition as determined (in regard to

the succession of time). Now this synthetical unity, as the a priori condition under which I conjoin the

manifold of an intuition, is, if I make abstraction of the permanent form of my internal intuition (that is to

say, of time), the category of cause, by means of which, when applied to my sensibility, I determine

everything that occurs according to relations of time. Consequently apprehension in such an event, and the

event itself, as far as regards the possibility of its perception, stands under the conception of the relation of

Categories are conceptions which prescribe laws a priori to phenomena, consequently to nature as the

complex of all phenomena (natura materialiter spectata). And now the question arises inasmuch as these

categories are not derived from nature, and do not regulate themselves according to her as their model (for in

that case they would be empirical) how it is conceivable that nature must regulate herself according to them,

in other words, how the categories can determine a priori the synthesis of the manifold of nature, and yet not

It is not in the least more difficult to conceive how the laws of the phenomena of nature must harmonize with

the understanding and with its a priori form that is, its faculty of conjoining the manifold than it is to

understand how the phenomena themselves must correspond with the a priori form of our sensuous intuition.

For laws do not exist in the phenomena any more than the phenomena exist as things in themselves. Laws do

not exist except by relation to the subject in which the phenomena inhere, in so far as it possesses

understanding, just as phenomena have no existence except by relation to the same existing subject in so far

as it has senses. To things as things in themselves, conformability to law must necessarily belong

independently of an understanding to cognize them. But phenomena are only representations of things which

are utterly unknown in respect to what they are in themselves. But as mere representations, they stand under

no law of conjunction except that which the conjoining faculty prescribes. Now that which conjoins the

manifold of sensuous intuition is imagination, a mental act to which understanding contributes unity of

intellectual synthesis, and sensibility, manifoldness of apprehension. Now as all possible perception depends

on the synthesis of apprehension, and this empirical synthesis itself on the transcendental, consequently on

the categories, it is evident that all possible perceptions, and therefore everything that can attain to empirical

consciousness, that is, all phenomena of nature, must, as regards their conjunction, be subject to the

categories. And nature (considered merely as nature in general) is dependent on them. as the original ground

of her necessary conformability to law (as natura formaliter spectata). But the pure faculty (of the

understanding) of prescribing laws a priori to phenomena by means of mere categories, is not competent to

enounce other or more laws than those on which a nature in general, as a conformability to law of phenomena

of space and time, depends. Particular laws, inasmuch as they concern empirically determined phenomena,

cannot be entirely deduced from pure laws, although they all stand under them. Experience must be

superadded in order to know these particular laws; but in regard to experience in general, and everything that

can be cognized as an object thereof, these a priori laws are our only rule and guide.

We cannot think any object except by means of the categories; we cannot cognize any thought except by

means of intuitions corresponding to these conceptions. Now all our intuitions are sensuous, and our

cognition, in so far as the object of it is given, is empirical. But empirical cognition is experience;

consequently no a priori cognition is possible for us, except of objects of possible experience.*

*Lest my readers should stumble at this assertion, and the conclusions that may be too rashly drawn from it, I

must remind them that the categories in the act of thought are by no means limited by the conditions of our

sensuous intuition, but have an unbounded sphere of action. It is only the cognition of the object of thought,

the determining of the object, which requires intuition. In the absence of intuition, our thought of an object

may still have true and useful consequences in regard to the exercise of reason by the subject. But as this

exercise of reason is not always directed on the determination of the object, in other words, on cognition

thereof, but also on the determination of the subject and its volition, I do not intend to treat of it in this place.

But this cognition, which is limited to objects of experience, is not for that reason derived entirely, from,

experience, but and this is asserted of the pure intuitions and the pure conceptions of the understanding

there are, unquestionably, elements of cognition, which exist in the mind a priori. Now there are only two

ways in which a necessary harmony of experience with the conceptions of its objects can be cogitated. Either

experience makes these conceptions possible, or the conceptions make experience possible. The former of

these statements will not bold good with respect to the categories (nor in regard to pure sensuous intuition),

for they are a priori conceptions, and therefore independent of experience. The assertion of an empirical

origin would attribute to them a sort of generatio aequivoca. Consequently, nothing remains but to adopt the

second alternative (which presents us with a system, as it were, of the epigenesis of pure reason), namely, that

on the part of the understanding the categories do contain the grounds of the possibility of all experience. But

with respect to the questions how they make experience possible, and what are the principles of the

possibility thereof with which they present us in their application to phenomena, the following section on the

It is quite possible that someone may propose a species of preformationsystem of pure reason a middle

way between the two to wit, that the categories are neither innate and first a priori principles of cognition,

nor derived from experience, but are merely subjective aptitudes for thought implanted in us

contemporaneously with our existence, which were so ordered and disposed by our Creator, that their

exercise perfectly harmonizes with the laws of nature which regulate experience. Now, not to mention that

with such an hypothesis it is impossible to say at what point we must stop in the employment of

predetermined aptitudes, the fact that the categories would in this case entirely lose that character of necessity

which is essentially involved in the very conception of them, is a conclusive objection to it. The conception

of cause, for example, which expresses the necessity of an effect under a presupposed condition, would be

false, if it rested only upon such an arbitrary subjective necessity of uniting certain empirical representations

according to such a rule of relation. I could not then say "The effect is connected with its cause in the object

(that is, necessarily)," but only, "I am so constituted that I can think this representation as so connected, and

not otherwise." Now this is just what the sceptic wants. For in this case, all our knowledge, depending on the

supposed objective validity of our judgement, is nothing but mere illusion; nor would there be wanting

people who would deny any such subjective necessity in respect to themselves, though they must feel it. At

all events, we could not dispute with any one on that which merely depends on the manner in which his

The foregoing deduction is an exposition of the pure conceptions of the understanding (and with them of all

theoretical a priori cognition), as principles of the possibility of experience, but of experience as the

determination of all phenomena in space and time in general of experience, finally, from the principle of the

original synthetical unity of apperception, as the form of the understanding in relation to time and space as

I consider the division by paragraphs to be necessary only up to this point, because we had to treat of the

elementary conceptions. As we now proceed to the exposition of the employment of these, I shall not

General logic is constructed upon a plan which coincides exactly with the division of the higher faculties of

cognition. These are, understanding, judgement, and reason. This science, accordingly, treats in its analytic of

conceptions, judgements, and conclusions in exact correspondence with the functions and order of those

mental powers which we include generally under the generic denomination of understanding.

As this merely formal logic makes abstraction of all content of cognition, whether pure or empirical, and

occupies itself with the mere form of thought (discursive cognition), it must contain in its analytic a canon for

reason. For the form of reason has its law, which, without taking into consideration the particular nature of

the cognition about which it is employed, can be discovered a priori, by the simple analysis of the action of

Transcendental logic, limited as it is to a determinate content, that of pure a priori cognitions, to wit, cannot

imitate general logic in this division. For it is evident that the transcendental employment of reason is not

objectively valid, and therefore does not belong to the logic of truth (that is, to analytic), but as a logic of

illusion, occupies a particular department in the scholastic system under the name of transcendental dialectic.

Understanding and judgement accordingly possess in transcendental logic a canon of objectively valid, and

therefore true exercise, and are comprehended in the analytical department of that logic. But reason, in her

endeavours to arrive by a priori means at some true statement concerning objects and to extend cognition

beyond the bounds of possible experience, is altogether dialectic, and her illusory assertions cannot be

Accordingly, the analytic of principles will be merely a canon for the faculty of judgement, for the instruction

of this faculty in its application to phenomena of the pure conceptions of the understanding, which contain

the necessary condition for the establishment of a priori laws. On this account, although the subject of the

following chapters is the especial principles of understanding, I shall make use of the term Doctrine of the

If understanding in general be defined as the faculty of laws or rules, the faculty of judgement may be termed

the faculty of subsumption under these rules; that is, of distinguishing whether this or that does or does not

stand under a given rule (casus datae legis). General logic contains no directions or precepts for the faculty of

judgement, nor can it contain any such. For as it makes abstraction of all content of cognition, no duty is left

for it, except that of exposing analytically the mere form of cognition in conceptions, judgements, and

conclusions, and of thereby establishing formal rules for all exercise of the understanding. Now if this logic

wished to give some general direction how we should subsume under these rules, that is, how we should

distinguish whether this or that did or did not stand under them, this again could not be done otherwise than

by means of a rule. But this rule, precisely because it is a rule, requires for itself direction from the faculty of

judgement. Thus, it is evident that the understanding is capable of being instructed by rules, but that the

judgement is a peculiar talent, which does not, and cannot require tuition, but only exercise. This faculty is

therefore the specific quality of the socalled mother wit, the want of which no scholastic discipline can

For although education may furnish, and, as it were, engraft upon a limited understanding rules borrowed

from other minds, yet the power of employing these rules correctly must belong to the pupil himself; and no

rule which we can prescribe to him with this purpose is, in the absence or deficiency of this gift of nature,

secure from misuse.* A physician therefore, a judge or a statesman, may have in his head many admirable

pathological, juridical, or political rules, in a degree that may enable him to be a profound teacher in his

particular science, and yet in the application of these rules he may very possibly blunder either because he is

wanting in natural judgement (though not in understanding) and, whilst he can comprehend the general in

abstracto, cannot distinguish whether a particular case in concreto ought to rank under the former; or because

his faculty of judgement bas not been sufficiently exercised by examples and real practice. Indeed, the grand

and only use of examples, is to sharpen the judgement. For as regards the correctness and precision of the

insight of the understanding, examples are commonly injurious rather than otherwise, because, as casus in

terminis they seldom adequately fulfil the conditions of the rule. Besides, they often weaken the power of our

understanding to apprehend rules or laws in their universality, independently of particular circumstances of

experience; and hence, accustom us to employ them more as formulae than as principles. Examples are thus

the gocart of the judgement, which he who is naturally deficient in that faculty cannot afford to dispense

*Deficiency in judgement is properly that which is called stupidity; and for such a failing we know no

remedy. A dull or narrowminded person, to whom nothing is wanting but a proper degree of understanding,

may be improved by tuition, even so far as to deserve the epithet of learned. But as such persons frequently

labour under a deficiency in the faculty of judgement, it is not uncommon to find men extremely learned who

in the application of their science betray a lamentable degree this irremediable want.

But although general logic cannot give directions to the faculty of judgement, the case is very different as

regards transcendental logic, insomuch that it appears to be the especial duty of the latter to secure and direct,

by means of determinate rules, the faculty of judgement in the employment of the pure understanding. For, as

a doctrine, that is, as an endeavour to enlarge the sphere of the understanding in regard to pure a priori

cognitions, philosophy is worse than useless, since from all the attempts hitherto made, little or no ground has

been gained. But, as a critique, in order to guard against the mistakes of the faculty of judgement (lapsus

judicii) in the employment of the few pure conceptions of the understanding which we possess, although its

use is in this case purely negative, philosophy is called upon to apply all its acuteness and penetration.

But transcendental philosophy has this peculiarity, that besides indicating the rule, or rather the general

condition for rules, which is given in the pure conception of the understanding, it can, at the same time,

indicate a priori the case to which the rule must be applied. The cause of the superiority which, in this respect,

transcendental philosophy possesses above all other sciences except mathematics, lies in this: it treats of

conceptions which must relate a priori to their objects, whose objective validity consequently cannot be

demonstrated a posteriori, and is, at the same time, under the obligation of presenting in general but sufficient

tests, the conditions under which objects can be given in harmony with those conceptions; otherwise they

would be mere logical forms, without content, and not pure conceptions of the understanding.

Our transcendental doctrine of the faculty of judgement will contain two chapters. The first will treat of the

sensuous condition under which alone pure conceptions of the understanding can be employed that is, of the

schematism of the pure understanding. The second will treat of those synthetical judgements which are

derived a priori from pure conceptions of the understanding under those conditions, and which lie a priori at

the foundation of all other cognitions, that is to say, it will treat of the principles of the pure understanding.

CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding. 66

In all subsumptions of an object under a conception, the representation of the object must be homogeneous

with the conception; in other words, the conception must contain that which is represented in the object to be

subsumed under it. For this is the meaning of the expression: "An object is contained under a conception."

Thus the empirical conception of a plate is homogeneous with the pure geometrical conception of a circle,

inasmuch as the roundness which is cogitated in the former is intuited in the latter.

But pure conceptions of the understanding, when compared with empirical intuitions, or even with sensuous

intuitions in general, are quite heterogeneous, and never can be discovered in any intuition. How then is the

subsumption of the latter under the former, and consequently the application of the categories to phenomena,

possible? For it is impossible to say, for example: "Causality can be intuited through the senses and is

contained in the phenomenon." This natural and important question forms the real cause of the necessity of

a transcendental doctrine of the faculty of judgement, with the purpose, to wit, of showing how pure

conceptions of the understanding can be applied to phenomena. In all other sciences, where the conceptions

by which the object is thought in the general are not so different and heterogeneous from those which

represent the object in concreto as it is given, it is quite unnecessary to institute any special inquiries

Now it is quite clear that there must be some third thing, which on the one side is homogeneous with the

category, and with the phenomenon on the other, and so makes the application of the former to the latter

possible. This mediating representation must be pure (without any empirical content), and yet must on the

one side be intellectual, on the other sensuous. Such a representation is the transcendental schema.

The conception of the understanding contains pure synthetical unity of the manifold in general. Time, as the

formal condition of the manifold of the internal sense, consequently of the conjunction of all representations,

contains a priori a manifold in the pure intuition. Now a transcendental determination of time is so far

homogeneous with the category, which constitutes the unity thereof, that it is universal and rests upon a rule a

priori. On the other hand, it is so far homogeneous with the phenomenon, inasmuch as time is contained in

every empirical representation of the manifold. Thus an application of the category to phenomena becomes

possible, by means of the transcendental determination of time, which, as the schema of the conceptions of

After what has been proved in our deduction of the categories, no one, it is to be hoped, can hesitate as to the

proper decision of the question, whether the employment of these pure conceptions of the understanding

ought to be merely empirical or also transcendental; in other words, whether the categories, as conditions of a

possible experience, relate a priori solely to phenomena, or whether, as conditions of the possibility of things

in general, their application can be extended to objects as things in themselves. For we have there seen that

conceptions are quite impossible, and utterly without signification, unless either to them, or at least to the

elements of which they consist, an object be given; and that, consequently, they cannot possibly apply to

objects as things in themselves without regard to the question whether and how these may be given to us;

and, further, that the only manner in which objects can be given to us is by means of the modification of our

sensibility; and, finally, that pure a priori conceptions, in addition to the function of the understanding in the

category, must contain a priori formal conditions of sensibility (of the internal sense, namely), which again

contain the general condition under which alone the category can be applied to any object. This formal and

pure condition of sensibility, to which the conception of the understanding is restricted in its employment, we

shall name the schema of the conception of the understanding, and the procedure of the understanding with

The schema is, in itself, always a mere product of the imagination. But, as the synthesis of imagination has

for its aim no single intuition, but merely unity in the determination of sensibility, the schema is clearly

distinguishable from the image. Thus, if I place five points one after another.... this is an image of the number

five. On the other hand, if I only think a number in general, which may be either five or a hundred, this

CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding. 67

thought is rather the representation of a method of representing in an image a sum (e.g., a thousand) in

conformity with a conception, than the image itself, an image which I should find some little difficulty in

reviewing, and comparing with the conception. Now this representation of a general procedure of the

imagination to present its image to a conception, I call the schema of this conception.

In truth, it is not images of objects, but schemata, which lie at the foundation of our pure sensuous

conceptions. No image could ever be adequate to our conception of a triangle in general. For the generalness

of the conception it never could attain to, as this includes under itself all triangles, whether rightangled,

acuteangled, etc., whilst the image would always be limited to a single part of this sphere. The schema of

the triangle can exist nowhere else than in thought, and it indicates a rule of the synthesis of the imagination

in regard to pure figures in space. Still less is an object of experience, or an image of the object, ever to the

empirical conception. On the contrary, the conception always relates immediately to the schema of the

imagination, as a rule for the determination of our intuition, in conformity with a certain general conception.

The conception of a dog indicates a rule, according to which my imagination can delineate the figure of a

fourfooted animal in general, without being limited to any particular individual form which experience

presents to me, or indeed to any possible image that I can represent to myself in concreto. This schematism of

our understanding in regard to phenomena and their mere form, is an art, hidden in the depths of the human

soul, whose true modes of action we shall only with difficulty discover and unveil. Thus much only can we

say: "The image is a product of the empirical faculty of the productive imagination the schema of sensuous

conceptions (of figures in space, for example) is a product, and, as it were, a monogram of the pure

imagination a priori, whereby and according to which images first become possible, which, however, can be

connected with the conception only mediately by means of the schema which they indicate, and are in

themselves never fully adequate to it." On the other hand, the schema of a pure conception of the

understanding is something that cannot be reduced into any image it is nothing else than the pure synthesis

expressed by the category, conformably, to a rule of unity according to conceptions. It is a transcendental

product of the imagination, a product which concerns the determination of the internal sense, according to

conditions of its form (time) in respect to all representations, in so far as these representations must be

Without entering upon a dry and tedious analysis of the essential requisites of transcendental schemata of the

pure conceptions of the understanding, we shall rather proceed at once to give an explanation of them

For the external sense the pure image of all quantities (quantorum) is space; the pure image of all objects of

sense in general, is time. But the pure schema of quantity (quantitatis) as a conception of the understanding, is

number, a representation which comprehends the successive addition of one to one (homogeneous quantities).

Thus, number is nothing else than the unity of the synthesis of the manifold in a homogeneous intuition, by

Reality, in the pure conception of the understanding, is that which corresponds to a sensation in general; that,

consequently, the conception of which indicates a being (in time). Negation is that the conception of which

represents a notbeing (in time). The opposition of these two consists therefore in the difference of one and

the same time, as a time filled or a time empty. Now as time is only the form of intuition, consequently of

objects as phenomena, that which in objects corresponds to sensation is the transcendental matter of all

objects as things in themselves (Sachheit, reality). Now every sensation has a degree or quantity by which it

can fill time, that is to say, the internal sense in respect of the representation of an object, more or less, until it

vanishes into nothing (= 0 = negatio). Thus there is a relation and connection between reality and negation, or

rather a transition from the former to the latter, which makes every reality representable to us as a quantum;

and the schema of a reality as the quantity of something in so far as it fills time, is exactly this continuous and

uniform generation of the reality in time, as we descend in time from the sensation which has a certain

degree, down to the vanishing thereof, or gradually ascend from negation to the quantity thereof.

CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding. 68

The schema of substance is the permanence of the real in time; that is, the representation of it as a substratum

of the empirical determination of time; a substratum which therefore remains, whilst all else changes. (Time

passes not, but in it passes the existence of the changeable. To time, therefore, which is itself unchangeable

and permanent, corresponds that which in the phenomenon is unchangeable in existence, that is, substance,

and it is only by it that the succession and coexistence of phenomena can be determined in regard to time.)

The schema of cause and of the causality of a thing is the real which, when posited, is always followed by

something else. It consists, therefore, in the succession of the manifold, in so far as that succession is

The schema of community (reciprocity of action and reaction), or the reciprocal causality of substances in

respect of their accidents, is the coexistence of the determinations of the one with those of the other,

The schema of possibility is the accordance of the synthesis of different representations with the conditions of

time in general (as, for example, opposites cannot exist together at the same time in the same thing, but only

after each other), and is therefore the determination of the representation of a thing at any time.

It is clear, from all this, that the schema of the category of quantity contains and represents the generation

(synthesis) of time itself, in the successive apprehension of an object; the schema of quality the synthesis of

sensation with the representation of time, or the filling up of time; the schema of relation the relation of

perceptions to each other in all time (that is, according to a rule of the determination of time): and finally, the

schema of modality and its categories, time itself, as the correlative of the determination of an object

whether it does belong to time, and how. The schemata, therefore, are nothing but a priori determinations of

time according to rules, and these, in regard to all possible objects, following the arrangement of the

categories, relate to the series in time, the content in time, the order in time, and finally, to the complex or

Hence it is apparent that the schematism of the understanding, by means of the transcendental synthesis of the

imagination, amounts to nothing else than the unity of the manifold of intuition in the internal sense, and thus

indirectly to the unity of apperception, as a function corresponding to the internal sense (a receptivity). Thus,

the schemata of the pure conceptions of the understanding are the true and only conditions whereby our

understanding receives an application to objects, and consequently significance. Finally, therefore, the

categories are only capable of empirical use, inasmuch as they serve merely to subject phenomena to the

universal rules of synthesis, by means of an a priori necessary unity (on account of the necessary union of all

consciousness in one original apperception); and so to render them susceptible of a complete connection in

one experience. But within this whole of possible experience lie all our cognitions, and in the universal

relation to this experience consists transcendental truth, which antecedes all empirical truth, and renders the

It is, however, evident at first sight, that although the schemata of sensibility are the sole agents in realizing

the categories, they do, nevertheless, also restrict them, that is, they limit the categories by conditions which

lie beyond the sphere of understanding namely, in sensibility. Hence the schema is properly only the

phenomenon, or the sensuous conception of an object in harmony with the category. (Numerus est quantitas

phaenomenon sensatio realitas phaenomenon; constans et perdurabile rerum substantia phaenomenon

aeternitas, necessitas, phaenomena, etc.) Now, if we remove a restrictive condition, we thereby amplify, it

appears, the formerly limited conception. In this way, the categories in their pure signification, free from all

CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding. 69

conditions of sensibility, ought to be valid of things as they are, and not, as the schemata represent them,

merely as they appear; and consequently the categories must have a significance far more extended, and

wholly independent of all schemata. In truth, there does always remain to the pure conceptions of the

understanding, after abstracting every sensuous condition, a value and significance, which is, however,

merely logical. But in this case, no object is given them, and therefore they have no meaning sufficient to

afford us a conception of an object. The notion of substance, for example, if we leave out the sensuous

determination of permanence, would mean nothing more than a something which can be cogitated as subject,

without the possibility of becoming a predicate to anything else. Of this representation I can make nothing,

inasmuch as it does not indicate to me what determinations the thing possesses which must thus be valid as

premier subject. Consequently, the categories, without schemata are merely functions of the understanding

for the production of conceptions, but do not represent any object. This significance they derive from

sensibility, which at the same time realizes the understanding and restricts it.

In the foregoing chapter we have merely considered the general conditions under which alone the

transcendental faculty of judgement is justified in using the pure conceptions of the understanding for

synthetical judgements. Our duty at present is to exhibit in systematic connection those judgements which the

understanding really produces a priori. For this purpose, our table of the categories will certainly afford us the

natural and safe guidance. For it is precisely the categories whose application to possible experience must

constitute all pure a priori cognition of the understanding; and the relation of which to sensibility will, on that

very account, present us with a complete and systematic catalogue of all the transcendental principles of the

Principles a priori are so called, not merely because they contain in themselves the grounds of other

judgements, but also because they themselves are not grounded in higher and more general cognitions. This

peculiarity, however, does not raise them altogether above the need of a proof. For although there could be

found no higher cognition, and therefore no objective proof, and although such a principle rather serves as the

foundation for all cognition of the object, this by no means hinders us from drawing a proof from the

subjective sources of the possibility of the cognition of an object. Such a proof is necessary, moreover,

because without it the principle might be liable to the imputation of being a mere gratuitous assertion.

In the second place, we shall limit our investigations to those principles which relate to the categories. For as

to the principles of transcendental aesthetic, according to which space and time are the conditions of the

possibility of things as phenomena, as also the restriction of these principles, namely, that they cannot be

applied to objects as things in themselves these, of course, do not fall within the scope of our present

inquiry. In like manner, the principles of mathematical science form no part of this system, because they are

all drawn from intuition, and not from the pure conception of the understanding. The possibility of these

principles, however, will necessarily be considered here, inasmuch as they are synthetical judgements a

priori, not indeed for the purpose of proving their accuracy and apodeictic certainty, which is unnecessary,

but merely to render conceivable and deduce the possibility of such evident a priori cognitions.

But we shall have also to speak of the principle of analytical judgements, in opposition to synthetical

judgements, which is the proper subject of our inquiries, because this very opposition will free the theory of

the latter from all ambiguity, and place it clearly before our eyes in its true nature.

Whatever may be the content of our cognition, and in whatever manner our cognition may be related to its

object, the universal, although only negative conditions of all our judgements is that they do not contradict

themselves; otherwise these judgements are in themselves (even without respect to the object) nothing. But

although there may exist no contradiction in our judgement, it may nevertheless connect conceptions in such

a manner that they do not correspond to the object, or without any grounds either a priori or a posteriori for

arriving at such a judgement, and thus, without being selfcontradictory, a judgement may nevertheless be

Now, the proposition: "No subject can have a predicate that contradicts it," is called the principle of

contradiction, and is a universal but purely negative criterion of all truth. But it belongs to logic alone,

because it is valid of cognitions, merely as cognitions and without respect to their content, and declares that

the contradiction entirely nullifies them. We can also, however, make a positive use of this principle, that is,

not merely to banish falsehood and error (in so far as it rests upon contradiction), but also for the cognition of

truth. For if the judgement is analytical, be it affirmative or negative, its truth must always be recognizable by

means of the principle of contradiction. For the contrary of that which lies and is cogitated as conception in

the cognition of the object will be always properly negatived, but the conception itself must always be

affirmed of the object, inasmuch as the contrary thereof would be in contradiction to the object.

We must therefore hold the principle of contradiction to be the universal and fully sufficient Principle of all

analytical cognition. But as a sufficient criterion of truth, it has no further utility or authority. For the fact that

no cognition can be at variance with this principle without nullifying itself, constitutes this principle the sine

qua non, but not the determining ground of the truth of our cognition. As our business at present is properly

with the synthetical part of our knowledge only, we shall always be on our guard not to transgress this

inviolable principle; but at the same time not to expect from it any direct assistance in the establishment of

There exists, however, a formula of this celebrated principle a principle merely formal and entirely without

content which contains a synthesis that has been inadvertently and quite unnecessarily mixed up with it. It is

this: "It is impossible for a thing to be and not to be at the same time." Not to mention the superfluousness of

the addition of the word impossible to indicate the apodeictic certainty, which ought to be selfevident from

the proposition itself, the proposition is affected by the condition of time, and as it were says: "A thing = A,

which is something = B, cannot at the same time be nonB." But both, B as well as nonB, may quite well

exist in succession. For example, a man who is young cannot at the same time be old; but the same man can

very well be at one time young, and at another not young, that is, old. Now the principle of contradiction as a

merely logical proposition must not by any means limit its application merely to relations of time, and

consequently a formula like the preceding is quite foreign to its true purpose. The misunderstanding arises in

this way. We first of all separate a predicate of a thing from the conception of the thing, and afterwards

connect with this predicate its opposite, and hence do not establish any contradiction with the subject, but

only with its predicate, which has been conjoined with the subject synthetically a contradiction, moreover,

which obtains only when the first and second predicate are affirmed in the same time. If I say: "A man who is

ignorant is not learned," the condition "at the same time" must be added, for he who is at one time ignorant,

may at another be learned. But if I say: "No ignorant man is a learned man," the proposition is analytical,

because the characteristic ignorance is now a constituent part of the conception of the subject; and in this case

the negative proposition is evident immediately from the proposition of contradiction, without the necessity

of adding the condition "the same time." This is the reason why I have altered the formula of this principle

The explanation of the possibility of synthetical judgements is a task with which general logic has nothing to

do; indeed she needs not even be acquainted with its name. But in transcendental logic it is the most

important matter to be dealt with indeed the only one, if the question is of the possibility of synthetical

judgements a priori, the conditions and extent of their validity. For when this question is fully decided, it can

reach its aim with perfect ease, the determination, to wit, of the extent and limits of the pure understanding.

In an analytical judgement I do not go beyond the given conception, in order to arrive at some decision

respecting it. If the judgement is affirmative, I predicate of the conception only that which was already

cogitated in it; if negative, I merely exclude from the conception its contrary. But in synthetical judgements, I

must go beyond the given conception, in order to cogitate, in relation with it, something quite different from

that which was cogitated in it, a relation which is consequently never one either of identity or contradiction,

and by means of which the truth or error of the judgement cannot be discerned merely from the judgement

Granted, then, that we must go out beyond a given conception, in order to compare it synthetically with

another, a third thing is necessary, in which alone the synthesis of two conceptions can originate. Now what

is this tertium quid that is to be the medium of all synthetical judgements? It is only a complex in which all

our representations are contained, the internal sense to wit, and its form a priori, time.

The synthesis of our representations rests upon the imagination; their synthetical unity (which is requisite to a

judgement), upon the unity of apperception. In this, therefore, is to be sought the possibility of synthetical

judgements, and as all three contain the sources of a priori representations, the possibility of pure synthetical

judgements also; nay, they are necessary upon these grounds, if we are to possess a knowledge of objects,

If a cognition is to have objective reality, that is, to relate to an object, and possess sense and meaning in

respect to it, it is necessary that the object be given in some way or another. Without this, our conceptions are

empty, and we may indeed have thought by means of them, but by such thinking we have not, in fact,

cognized anything, we have merely played with representation. To give an object, if this expression be

understood in the sense of "to present" the object, not mediately but immediately in intuition, means nothing

else than to apply the representation of it to experience, be that experience real or only possible. Space and

time themselves, pure as these conceptions are from all that is empirical, and certain as it is that they are

represented fully a priori in the mind, would be completely without objective validity, and without sense and

significance, if their necessary use in the objects of experience were not shown. Nay, the representation of

them is a mere schema, that always relates to the reproductive imagination, which calls up the objects of

experience, without which they have no meaning. And so it is with all conceptions without distinction.

The possibility of experience is, then, that which gives objective reality to all our a priori cognitions. Now

experience depends upon the synthetical unity of phenomena, that is, upon a synthesis according to

conceptions of the object of phenomena in general, a synthesis without which experience never could become

knowledge, but would be merely a rhapsody of perceptions, never fitting together into any connected text,

according to rules of a thoroughly united (possible) consciousness, and therefore never subjected to the

transcendental and necessary unity of apperception. Experience has therefore for a foundation, a priori

principles of its form, that is to say, general rules of unity in the synthesis of phenomena, the objective reality

of which rules, as necessary conditions even of the possibility of experience can which rules, as necessary

conditions even of the possibility of experience can always be shown in experience. But apart from this

relation, a priori synthetical propositions are absolutely impossible, because they have no third term, that is,

no pure object, in which the synthetical unity can exhibit the objective reality of its conceptions.

Although, then, respecting space, or the forms which productive imagination describes therein, we do cognize

much a priori in synthetical judgements, and are really in no need of experience for this purpose, such

knowledge would nevertheless amount to nothing but a busy trifling with a mere chimera, were not space to

be considered as the condition of the phenomena which constitute the material of external experience. Hence

those pure synthetical judgements do relate, though but mediately, to possible experience, or rather to the

possibility of experience, and upon that alone is founded the objective validity of their synthesis.

While then, on the one hand, experience, as empirical synthesis, is the only possible mode of cognition which

gives reality to all other synthesis; on the other hand, this latter synthesis, as cognition a priori, possesses

truth, that is, accordance with its object, only in so far as it contains nothing more than what is necessary to

Accordingly, the supreme principle of all synthetical judgements is: "Every object is subject to the necessary

conditions of the synthetical unity of the manifold of intuition in a possible experience."

A priori synthetical judgements are possible when we apply the formal conditions of the a priori intuition, the

synthesis of the imagination, and the necessary unity of that synthesis in a transcendental apperception, to a

possible cognition of experience, and say: "The conditions of the possibility of experience in general are at

the same time conditions of the possibility of the objects of experience, and have, for that reason, objective

That principles exist at all is to be ascribed solely to the pure understanding, which is not only the faculty of

rules in regard to that which happens, but is even the source of principles according to which everything that

can be presented to us as an object is necessarily subject to rules, because without such rules we never could

attain to cognition of an object. Even the laws of nature, if they are contemplated as principles of the

empirical use of the understanding, possess also a characteristic of necessity, and we may therefore at least

expect them to be determined upon grounds which are valid a priori and antecedent to all experience. But all

laws of nature, without distinction, are subject to higher principles of the understanding, inasmuch as the

former are merely applications of the latter to particular cases of experience. These higher principles alone

therefore give the conception, which contains the necessary condition, and, as it were, the exponent of a rule;

There is no danger of our mistaking merely empirical principles for principles of the pure understanding, or

conversely; for the character of necessity, according to conceptions which distinguish the latter, and the

absence of this in every empirical proposition, how extensively valid soever it may be, is a perfect safeguard

against confounding them. There are, however, pure principles a priori, which nevertheless I should not

ascribe to the pure understanding for this reason, that they are not derived from pure conceptions, but

(although by the mediation of the understanding) from pure intuitions. But understanding is the faculty of

conceptions. Such principles mathematical science possesses, but their application to experience,

consequently their objective validity, nay the possibility of such a priori synthetical cognitions (the deduction

On this account, I shall not reckon among my principles those of mathematics; though I shall include those

upon the possibility and objective validity a priori, of principles of the mathematical science, which,

consequently, are to be looked upon as the principle of these, and which proceed from conceptions to

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 73

In the application of the pure conceptions of the understanding to possible experience, the employment of

their synthesis is either mathematical or dynamical, for it is directed partly on the intuition alone, partly on

the existence of a phenomenon. But the a priori conditions of intuition are in relation to a possible experience

absolutely necessary, those of the existence of objects of a possible empirical intuition are in themselves

contingent. Hence the principles of the mathematical use of the categories will possess a character of absolute

necessity, that is, will be apodeictic; those, on the other hand, of the dynamical use, the character of an a

priori necessity indeed, but only under the condition of empirical thought in an experience, therefore only

mediately and indirectly. Consequently they will not possess that immediate evidence which is peculiar to the

former, although their application to experience does not, for that reason, lose its truth and certitude. But of

this point we shall be better able to judge at the conclusion of this system of principles.

The table of the categories is naturally our guide to the table of principles, because these are nothing else than

rules for the objective employment of the former. Accordingly, all principles of the pure understanding are:

These appellations I have chosen advisedly, in order that we might not lose sight of the distinctions in respect

of the evidence and the employment of these principles. It will, however, soon appear that a fact which

concerns both the evidence of these principles, and the a priori determination of phenomena according to

the categories of quantity and quality (if we attend merely to the form of these), the principles of these

categories are distinguishable from those of the two others, in as much as the former are possessed of an

intuitive, but the latter of a merely discursive, though in both instances a complete, certitude. I shall therefore

call the former mathematical, and the latter dynamical principles.* It must be observed, however, that by

these terms I mean just as little in the one case the principles of mathematics as those of general (physical)

dynamics in the other. I have here in view merely the principles of the pure understanding, in their

application to the internal sense (without distinction of the representations given therein), by means of which

the sciences of mathematics and dynamics become possible. Accordingly, I have named these principles

rather with reference to their application than their content; and I shall now proceed to consider them in the

*All combination (conjunctio) is either composition (compositio) or connection (nexus). The former is the

synthesis of a manifold, the parts of which do not necessarily belong to each other. For example, the two

triangles into which a square is divided by a diagonal, do not necessarily belong to each other, and of this

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 74

kind is the synthesis of the homogeneous in everything that can be mathematically considered. This synthesis

can be divided into those of aggregation and coalition, the former of which is applied to extensive, the latter

to intensive quantities. The second sort of combination (nexus) is the synthesis of a manifold, in so far as its

parts do belong necessarily to each other; for example, the accident to a substance, or the effect to the cause.

Consequently it is a synthesis of that which though heterogeneous, is represented as connected a priori. This

combination not an arbitrary one I entitle dynamical because it concerns the connection of the existence of

the manifold. This, again, may be divided into the physical synthesis, of the phenomena divided among each

other, and the metaphysical synthesis, or the connection of phenomena a priori in the faculty of cognition.

All phenomena contain, as regards their form, an intuition in space and time, which lies a priori at the

foundation of all without exception. Phenomena, therefore, cannot be apprehended, that is, received into

empirical consciousness otherwise than through the synthesis of a manifold, through which the

representations of a determinate space or time are generated; that is to say, through the composition of the

homogeneous and the consciousness of the synthetical unity of this manifold (homogeneous). Now the

consciousness of a homogeneous manifold in intuition, in so far as thereby the representation of an object is

rendered possible, is the conception of a quantity (quanti). Consequently, even the perception of an object as

phenomenon is possible only through the same synthetical unity of the manifold of the given sensuous

intuition, through which the unity of the composition of the homogeneous manifold in the conception of a

quantity is cogitated; that is to say, all phenomena are quantities, and extensive quantities, because as

intuitions in space or time they must be represented by means of the same synthesis through which space and

An extensive quantity I call that wherein the representation of the parts renders possible (and therefore

necessarily antecedes) the representation of the whole. I cannot represent to myself any line, however small,

without drawing it in thought, that is, without generating from a point all its parts one after another, and in

this way alone producing this intuition. Precisely the same is the case with every, even the smallest, portion

of time. I cogitate therein only the successive progress from one moment to another, and hence, by means of

the different portions of time and the addition of them, a determinate quantity of time is produced. As the

pure intuition in all phenomena is either time or space, so is every phenomenon in its character of intuition an

extensive quantity, inasmuch as it can only be cognized in our apprehension by successive synthesis (from

part to part). All phenomena are, accordingly, to be considered as aggregates, that is, as a collection of

previously given parts; which is not the case with every sort of quantities, but only with those which are

On this successive synthesis of the productive imagination, in the generation of figures, is founded the

mathematics of extension, or geometry, with its axioms, which express the conditions of sensuous intuition a

priori, under which alone the schema of a pure conception of external intuition can exist; for example, "be

tween two points only one straight line is possible," "two straight lines cannot enclose a space," etc. These are

But, as regards the quantity of a thing (quantitas), that is to say, the answer to the question: "How large is this

or that object?" although, in respect to this question, we have various propositions synthetical and

immediately certain (indemonstrabilia); we have, in the proper sense of the term, no axioms. For example, the

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 75

propositions: "If equals be added to equals, the wholes are equal"; "If equals be taken from equals, the

remainders are equal"; are analytical, because I am immediately conscious of the identity of the production of

the one quantity with the production of the other; whereas axioms must be a priori synthetical propositions.

On the other hand, the selfevident propositions as to the relation of numbers, are certainly synthetical but

not universal, like those of geometry, and for this reason cannot be called axioms, but numerical formulae.

That 7 + 5 = 12 is not an analytical proposition. For neither in the representation of seven, nor of five, nor of

the composition of the two numbers, do I cogitate the number twelve. (Whether I cogitate the number in the

addition of both, is not at present the question; for in the case of an analytical proposition, the only point is

whether I really cogitate the predicate in the representation of the subject.) But although the proposition is

synthetical, it is nevertheless only a singular proposition. In so far as regard is here had merely to the

synthesis of the homogeneous (the units), it cannot take place except in one manner, although our use of these

numbers is afterwards general. If I say: "A triangle can be constructed with three lines, any two of which

taken together are greater than the third," I exercise merely the pure function of the productive imagination,

which may draw the lines longer or shorter and construct the angles at its pleasure. On the contrary, the

number seven is possible only in one manner, and so is likewise the number twelve, which results from the

synthesis of seven and five. Such propositions, then, cannot be termed axioms (for in that case we should

This transcendental principle of the mathematics of phenomena greatly enlarges our a priori cognition. For it

is by this principle alone that pure mathematics is rendered applicable in all its precision to objects of

experience, and without it the validity of this application would not be so selfevident; on the contrary,

contradictions and confusions have often arisen on this very point. Phenomena are not things in themselves.

Empirical intuition is possible only through pure intuition (of space and time); consequently, what geometry

affirms of the latter, is indisputably valid of the former. All evasions, such as the statement that objects of

sense do not conform to the rules of construction in space (for example, to the rule of the infinite divisibility

of lines or angles), must fall to the ground. For, if these objections hold good, we deny to space, and with it to

all mathematics, objective validity, and no longer know wherefore, and how far, mathematics can be applied

to phenomena. The synthesis of spaces and times as the essential form of all intuition, is that which renders

possible the apprehension of a phenomenon, and therefore every external experience, consequently all

cognition of the objects of experience; and whatever mathematics in its pure use proves of the former, must

necessarily hold good of the latter. All objections are but the chicaneries of an illinstructed reason, which

erroneously thinks to liberate the objects of sense from the formal conditions of our sensibility, and represents

these, although mere phenomena, as things in themselves, presented as such to our understanding. But in this

case, no a priori synthetical cognition of them could be possible, consequently not through pure conceptions

of space and the science which determines these conceptions, that is to say, geometry, would itself be

Perception is empirical consciousness, that is to say, a consciousness which contains an element of sensation.

Phenomena as objects of perception are not pure, that is, merely formal intuitions, like space and time, for

they cannot be perceived in themselves. They contain, then, over and above the intuition, the materials for an

object (through which is represented something existing in space or time), that is to say, they contain the real

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 76

of sensation, as a representation merely subjective, which gives us merely the consciousness that the subject

is affected, and which we refer to some external object. Now, a gradual transition from empirical

consciousness to pure consciousness is possible, inasmuch as the real in this consciousness entirely vanishes,

and there remains a merely formal consciousness (a priori) of the manifold in time and space; consequently

there is possible a synthesis also of the production of the quantity of a sensation from its commencement, that

is, from the pure intuition = 0 onwards up to a certain quantity of the sensation. Now as sensation in itself is

not an objective representation, and in it is to be found neither the intuition of space nor of time, it cannot

possess any extensive quantity, and yet there does belong to it a quantity (and that by means of its

apprehension, in which empirical consciousness can within a certain time rise from nothing = 0 up to its

given amount), consequently an intensive quantity. And thus we must ascribe intensive quantity, that is, a

degree of influence on sense to all objects of perception, in so far as this perception contains sensation.

All cognition, by means of which I am enabled to cognize and determine a priori what belongs to empirical

cognition, may be called an anticipation; and without doubt this is the sense in which Epicurus employed his

expression prholepsis. But as there is in phenomena something which is never cognized a priori, which on

this account constitutes the proper difference between pure and empirical cognition, that is to say, sensation

(as the matter of perception), it follows, that sensation is just that element in cognition which cannot be at all

anticipated. On the other hand, we might very well term the pure determinations in space and time, as well in

regard to figure as to quantity, anticipations of phenomena, because they represent a priori that which may

always be given a posteriori in experience. But suppose that in every sensation, as sensation in general,

without any particular sensation being thought of, there existed something which could be cognized a priori,

this would deserve to be called anticipation in a special sense special, because it may seem surprising to

forestall experience, in that which concerns the matter of experience, and which we can only derive from

Apprehension, by means of sensation alone, fills only one moment, that is, if I do not take into consideration

a succession of many sensations. As that in the phenomenon, the apprehension of which is not a successive

synthesis advancing from parts to an entire representation, sensation has therefore no extensive quantity; the

want of sensation in a moment of time would represent it as empty, consequently = O. That which in the

empirical intuition corresponds to sensation is reality (realitas phaenomenon); that which corresponds to the

absence of it, negation = O. Now every sensation is capable of a diminution, so that it can decrease, and thus

gradually disappear. Therefore, between reality in a phenomenon and negation, there exists a continuous

concatenation of many possible intermediate sensations, the difference of which from each other is always

smaller than that between the given sensation and zero, or complete negation. That is to say, the real in a

phenomenon has always a quantity, which however is not discoverable in apprehension, inasmuch as

apprehension take place by means of mere sensation in one instant, and not by the successive synthesis of

many sensations, and therefore does not progress from parts to the whole. Consequently, it has a quantity, but

Now that quantity which is apprehended only as unity, and in which plurality can be represented only by

approximation to negation = O, I term intensive quantity. Consequently, reality in a phenomenon has

intensive quantity, that is, a degree. if we consider this reality as cause (be it of sensation or of another reality

in the phenomenon, for example, a change), we call the degree of reality in its character of cause a

momentum, for example, the momentum of weight; and for this reason, that the degree only indicates that

quantity the apprehension of which is not successive, but instantaneous. This, however, I touch upon only in

Accordingly, every sensation, consequently every reality in phenomena, however small it may be, has a

degree, that is, an intensive quantity, which may always be lessened, and between reality and negation there

exists a continuous connection of possible realities, and possible smaller perceptions. Every colour for

example, red has a degree, which, be it ever so small, is never the smallest, and so is it always with heat, the

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 77

This property of quantities, according to which no part of them is the smallest possible (no part simple), is

called their continuity. Space and time are quanta continua, because no part of them can be given, without

enclosing it within boundaries (points and moments), consequently, this given part is itself a space or a time.

Space, therefore, consists only of spaces, and time of times. Points and moments are only boundaries, that is,

the mere places or positions of their limitation. But places always presuppose intuitions which are to limit or

determine them; and we cannot conceive either space or time composed of constituent parts which are given

before space or time. Such quantities may also be called flowing, because synthesis (of the productive

imagination) in the production of these quantities is a progression in time, the continuity of which we are

All phenomena, then, are continuous quantities, in respect both to intuition and mere perception (sensation,

and with it reality). In the former case they are extensive quantities; in the latter, intensive. When the

synthesis of the manifold of a phenomenon is interrupted, there results merely an aggregate of several

phenomena, and not properly a phenomenon as a quantity, which is not produced by the mere continuation of

the productive synthesis of a certain kind, but by the repetition of a synthesis always ceasing. For example, if

I call thirteen dollars a sum or quantity of money, I employ the term quite correctly, inasmuch as I understand

by thirteen dollars the value of a mark in standard silver, which is, to be sure, a continuous quantity, in which

no part is the smallest, but every part might constitute a piece of money, which would contain material for

still smaller pieces. If, however, by the words thirteen dollars I understand so many coins (be their value in

silver what it may), it would be quite erroneous to use the expression a quantity of dollars; on the contrary, I

must call them aggregate, that is, a number of coins. And as in every number we must have unity as the

foundation, so a phenomenon taken as unity is a quantity, and as such always a continuous quantity (quantum

Now, seeing all phenomena, whether considered as extensive or intensive, are continuous quantities, the

proposition: "All change (transition of a thing from one state into another) is continuous," might be proved

here easily, and with mathematical evidence, were it not that the causality of a change lies, entirely beyond

the bounds of a transcendental philosophy, and presupposes empirical principles. For of the possibility of a

cause which changes the condition of things, that is, which determines them to the contrary to a certain given

state, the understanding gives us a priori no knowledge; not merely because it has no insight into the

possibility of it (for such insight is absent in several a priori cognitions), but because the notion of change

concerns only certain determinations of phenomena, which experience alone can acquaint us with, while their

cause lies in the unchangeable. But seeing that we have nothing which we could here employ but the pure

fundamental conceptions of all possible experience, among which of course nothing empirical can be

admitted, we dare not, without injuring the unity of our system, anticipate general physical science, which is

Nevertheless, we are in no want of proofs of the great influence which the principle above developed

exercises in the anticipation of perceptions, and even in supplying the want of them, so far as to shield us

If all reality in perception has a degree, between which and negation there is an endless sequence of ever

smaller degrees, and if, nevertheless, every sense must have a determinate degree of receptivity for

sensations; no perception, and consequently no experience is possible, which can prove, either immediately

or mediately, an entire absence of all reality in a phenomenon; in other words, it is impossible ever to draw

from experience a proof of the existence of empty space or of empty time. For in the first place, an entire

absence of reality in a sensuous intuition cannot of course be an object of perception; secondly, such absence

cannot be deduced from the contemplation of any single phenomenon, and the difference of the degrees in its

reality; nor ought it ever to be admitted in explanation of any phenomenon. For if even the complete intuition

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 78

of a determinate space or time is thoroughly real, that is, if no part thereof is empty, yet because every reality

has its degree, which, with the extensive quantity of the phenomenon unchanged, can diminish through

endless gradations down to nothing (the void), there must be infinitely graduated degrees, with which space

or time is filled, and the intensive quantity in different phenomena may be smaller or greater, although the

We shall give an example of this. Almost all natural philosophers, remarking a great difference in the

quantity of the matter of different kinds in bodies with the same volume (partly on account of the momentum

of gravity or weight, partly on account of the momentum of resistance to other bodies in motion), conclude

unanimously that this volume (extensive quantity of the phenomenon) must be void in all bodies, although in

different proportion. But who would suspect that these for the most part mathematical and mechanical

inquirers into nature should ground this conclusion solely on a metaphysical hypothesis a sort of hypothesis

which they profess to disparage and avoid? Yet this they do, in assuming that the real in space (I must not

here call it impenetrability or weight, because these are empirical conceptions) is always identical, and can

only be distinguished according to its extensive quantity, that is, multiplicity. Now to this presupposition, for

which they can have no ground in experience, and which consequently is merely metaphysical, I oppose a

transcendental demonstration, which it is true will not explain the difference in the filling up of spaces, but

which nevertheless completely does away with the supposed necessity of the abovementioned

presupposition that we cannot explain the said difference otherwise than by the hypothesis of empty spaces.

This demonstration, moreover, has the merit of setting the understanding at liberty to conceive this distinction

in a different manner, if the explanation of the fact requires any such hypothesis. For we perceive that

although two equal spaces may be completely filled by matters altogether different, so that in neither of them

is there left a single point wherein matter is not present, nevertheless, every reality has its degree (of

resistance or of weight), which, without diminution of the extensive quantity, can become less and less ad

infinitum, before it passes into nothingness and disappears. Thus an expansion which fills a space for

example, caloric, or any other reality in the phenomenal world can decrease in its degrees to infinity, yet

without leaving the smallest part of the space empty; on the contrary, filling it with those lesser degrees as

completely as another phenomenon could with greater. My intention here is by no means to maintain that this

is really the case with the difference of matters, in regard to their specific gravity; I wish only to prove, from

a principle of the pure understanding, that the nature of our perceptions makes such a mode of explanation

possible, and that it is erroneous to regard the real in a phenomenon as equal quoad its degree, and different

only quoad its aggregation and extensive quantity, and this, too, on the pretended authority of an a priori

Nevertheless, this principle of the anticipation of perception must somewhat startle an inquirer whom

initiation into transcendental philosophy has rendered cautious. We must naturally entertain some doubt

whether or not the understanding can enounce any such synthetical proposition as that respecting the degree

of all reality in phenomena, and consequently the possibility of the internal difference of sensation itself

abstraction being made of its empirical quality. Thus it is a question not unworthy of solution: "How the

understanding can pronounce synthetically and a priori respecting phenomena, and thus anticipate these, even

in that which is peculiarly and merely empirical, that, namely, which concerns sensation itself?"

The quality of sensation is in all cases merely empirical, and cannot be represented a priori (for example,

colours, taste, etc.). But the real that which corresponds to sensation in opposition to negation = O, only

represents something the conception of which in itself contains a being (ein seyn), and signifies nothing but

the synthesis in an empirical consciousness. That is to say, the empirical consciousness in the internal sense

can be raised from 0 to every higher degree, so that the very same extensive quantity of intuition, an

illuminated surface, for example, excites as great a sensation as an aggregate of many other surfaces less

illuminated. We can therefore make complete abstraction of the extensive quantity of a phenomenon, and

represent to ourselves in the mere sensation in a certain momentum, a synthesis of homogeneous ascension

from 0 up to the given empirical consciousness, All sensations therefore as such are given only a posteriori,

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 79

but this property thereof, namely, that they have a degree, can be known a priori. It is worthy of remark, that

in respect to quantities in general, we can cognize a priori only a single quality, namely, continuity; but in

respect to all quality (the real in phenomena), we cannot cognize a priori anything more than the intensive

quantity thereof, namely, that they have a degree. All else is left to experience.

Experience is an empirical cognition; that is to say, a cognition which determines an object by means of

perceptions. It is therefore a synthesis of perceptions, a synthesis which is not itself contained in perception,

but which contains the synthetical unity of the manifold of perception in a consciousness; and this unity

constitutes the essential of our cognition of objects of the senses, that is, of experience (not merely of

intuition or sensation). Now in experience our perceptions come together contingently, so that no character of

necessity in their connection appears, or can appear from the perceptions themselves, because apprehension is

only a placing together of the manifold of empirical intuition, and no representation of a necessity in the

connected existence of the phenomena which apprehension brings together, is to be discovered therein. But as

experience is a cognition of objects by means of perceptions, it follows that the relation of the existence of

the existence of the manifold must be represented in experience not as it is put together in time, but as it is

objectively in time. And as time itself cannot be perceived, the determination of the existence of objects in

time can only take place by means of their connection in time in general, consequently only by means of a

priori connecting conceptions. Now as these conceptions always possess the character of necessity,

experience is possible only by means of a representation of the necessary connection of perception.

The three modi of time are permanence, succession, and coexistence. Accordingly, there are three rules of all

relations of time in phenomena, according to which the existence of every phenomenon is determined in

respect of the unity of all time, and these antecede all experience and render it possible.

The general principle of all three analogies rests on the necessary unity of apperception in relation to all

possible empirical consciousness (perception) at every time, consequently, as this unity lies a priori at the

foundation of all mental operations, the principle rests on the synthetical unity of all phenomena according to

their relation in time. For the original apperception relates to our internal sense (the complex of all

representations), and indeed relates a priori to its form, that is to say, the relation of the manifold empirical

consciousness in time. Now this manifold must be combined in original apperception according to relations

of time a necessity imposed by the a priori transcendental unity of apperception, to which is subjected all

that can belong to my (i.e., my own) cognition, and therefore all that can become an object for me. This

synthetical and a priori determined unity in relation of perceptions in time is therefore the rule: "All empirical

determinations of time must be subject to rules of the general determination of time"; and the analogies of

These principles have this peculiarity, that they do not concern phenomena, and the synthesis of the empirical

intuition thereof, but merely the existence of phenomena and their relation to each other in regard to this

existence. Now the mode in which we apprehend a thing in a phenomenon can be determined a priori in such

a manner that the rule of its synthesis can give, that is to say, can produce this a priori intuition in every

empirical example. But the existence of phenomena cannot be known a priori, and although we could arrive

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 80

by this path at a conclusion of the fact of some existence, we could not cognize that existence determinately,

that is to say, we should be incapable of anticipating in what respect the empirical intuition of it would be

The two principles above mentioned, which I called mathematical, in consideration of the fact of their

authorizing the application of mathematic phenomena, relate to these phenomena only in regard to their

possibility, and instruct us how phenomena, as far as regards their intuition or the real in their perception, can

be generated according to the rules of a mathematical synthesis. Consequently, numerical quantities, and with

them the determination of a phenomenon as a quantity, can be employed in the one case as well as in the

other. Thus, for example, out of 200,000 illuminations by the moon, I might compose and give a priori, that is

construct, the degree of our sensations of the sunlight. We may therefore entitle these two principles

The case is very different with those principles whose province it is to subject the existence of phenomena to

rules a priori. For as existence does not admit of being constructed, it is clear that they must only concern the

relations of existence and be merely regulative principles. In this case, therefore, neither axioms nor

anticipations are to be thought of. Thus, if a perception is given us, in a certain relation of time to other

(although undetermined) perceptions, we cannot then say a priori, what and how great (in quantity) the other

perception necessarily connected with the former is, but only how it is connected, quoad its existence, in this

given modus of time. Analogies in philosophy mean something very different from that which they represent

in mathematics. In the latter they are formulae, which enounce the equality of two relations of quantity, and

are always constitutive, so that if two terms of the proportion are given, the third is also given, that is, can be

constructed by the aid of these formulae. But in philosophy, analogy is not the equality of two quantitative

but of two qualitative relations. In this case, from three given terms, I can give a priori and cognize the

relation to a fourth member, but not this fourth term itself, although I certainly possess a rule to guide me in

the search for this fourth term in experience, and a mark to assist me in discovering it. An analogy of

experience is therefore only a rule according to which unity of experience must arise out of perceptions in

respect to objects (phenomena) not as a constitutive, but merely as a regulative principle. The same holds

good also of the postulates of empirical thought in general, which relate to the synthesis of mere intuition

(which concerns the form of phenomena), the synthesis of perception (which concerns the matter of

phenomena), and the synthesis of experience (which concerns the relation of these perceptions). For they are

only regulative principles, and clearly distinguishable from the mathematical, which are constitutive, not

indeed in regard to the certainty which both possess a priori, but in the mode of evidence thereof,

But what has been observed of all synthetical propositions, and must be particularly remarked in this place, is

this, that these analogies possess significance and validity, not as principles of the transcendental, but only as

principles of the empirical use of the understanding, and their truth can therefore be proved only as such, and

that consequently the phenomena must not be subjoined directly under the categories, but only under their

schemata. For if the objects to which those principles must be applied were things in themselves, it would be

quite impossible to cognize aught concerning them synthetically a priori. But they are nothing but

phenomena; a complete knowledge of which a knowledge to which all principles a priori must at last relate

is the only possible experience. It follows that these principles can have nothing else for their aim than the

conditions of the empirical cognition in the unity of synthesis of phenomena. But this synthesis is cogitated

only in the schema of the pure conception of the understanding, of whose unity, as that of a synthesis in

general, the category contains the function unrestricted by any sensuous condition. These principles will

therefore authorize us to connect phenomena according to an analogy, with the logical and universal unity of

conceptions, and consequently to employ the categories in the principles themselves; but in the application of

them to experience, we shall use only their schemata, as the key to their proper application, instead of the

categories, or rather the latter as restricting conditions, under the title of "formulae" of the former.

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 81

All phenomena exist in time, wherein alone as substratum, that is, as the permanent form of the internal

intuition, coexistence and succession can be represented. Consequently time, in which all changes of

phenomena must be cogitated, remains and changes not, because it is that in which succession and

coexistence can be represented only as determinations thereof. Now, time in itself cannot be an object of

perception. It follows that in objects of perception, that is, in phenomena, there must be found a substratum

which represents time in general, and in which all change or coexistence can be perceived by means of the

relation of phenomena to it. But the substratum of all reality, that is, of all that pertains to the existence of

things, is substance; all that pertains to existence can be cogitated only as a determination of substance.

Consequently, the permanent, in relation to which alone can all relations of time in phenomena be

determined, is substance in the world of phenomena, that is, the real in phenomena, that which, as the

substratum of all change, remains ever the same. Accordingly, as this cannot change in existence, its quantity

Our apprehension of the manifold in a phenomenon is always successive, is Consequently always changing.

By it alone we could, therefore, never determine whether this manifold, as an object of experience, is

coexistent or successive, unless it had for a foundation something fixed and permanent, of the existence of

which all succession and coexistence are nothing but so many modes (modi of time). Only in the permanent,

then, are relations of time possible (for simultaneity and succession are the only relations in time); that is to

say, the permanent is the substratum of our empirical representation of time itself, in which alone all

determination of time is possible. Permanence is, in fact, just another expression for time, as the abiding

correlate of all existence of phenomena, and of all change, and of all coexistence. For change does not affect

time itself, but only the phenomena in time (just as coexistence cannot be regarded as a modus of time itself,

seeing that in time no parts are coexistent, but all successive). If we were to attribute succession to time itself,

we should be obliged to cogitate another time, in which this succession would be possible. It is only by

means of the permanent that existence in different parts of the successive series of time receives a quantity,

which we entitle duration. For in mere succession, existence is perpetually vanishing and recommencing, and

therefore never has even the least quantity. Without the permanent, then, no relation in time is possible. Now,

time in itself is not an object of perception; consequently the permanent in phenomena must be regarded as

the substratum of all determination of time, and consequently also as the condition of the possibility of all

synthetical unity of perceptions, that is, of experience; and all existence and all change in time can only be

regarded as a mode in the existence of that which abides unchangeably. Therefore, in all phenomena, the

permanent is the object in itself, that is, the substance (phenomenon); but all that changes or can change

belongs only to the mode of the existence of this substance or substances, consequently to its determinations.

I find that in all ages not only the philosopher, but even the common understanding, has preposited this

permanence as a substratum of all change in phenomena; indeed, I am compelled to believe that they will

always accept this as an indubitable fact. Only the philosopher expresses himself in a more precise and

definite manner, when he says: "In all changes in the world, the substance remains, and the accidents alone

are changeable." But of this decidedly synthetical proposition, I nowhere meet with even an attempt at proof;

nay, it very rarely has the good fortune to stand, as it deserves to do, at the head of the pure and entirely a

priori laws of nature. In truth, the statement that substance is permanent, is tautological. For this very

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 82

permanence is the ground on which we apply the category of substance to the phenomenon; and we should

have been obliged to prove that in all phenomena there is something permanent, of the existence of which the

changeable is nothing but a determination. But because a proof of this nature cannot be dogmatical, that is,

cannot be drawn from conceptions, inasmuch as it concerns a synthetical proposition a priori, and as

philosophers never reflected that such propositions are valid only in relation to possible experience, and

therefore cannot be proved except by means of a deduction of the possibility of experience, it is no wonder

that while it has served as the foundation of all experience (for we feel the need of it in empirical cognition),

A philosopher was asked: "What is the weight of smoke?" He answered: "Subtract from the weight of the

burnt wood the weight of the remaining ashes, and you will have the weight of the smoke." Thus he

presumed it to be incontrovertible that even in fire the matter (substance) does not perish, but that only the

form of it undergoes a change. In like manner was the saying: "From nothing comes nothing," only another

inference from the principle or permanence, or rather of the everabiding existence of the true subject in

phenomena. For if that in the phenomenon which we call substance is to be the proper substratum of all

determination of time, it follows that all existence in past as well as in future time, must be determinable by

means of it alone. Hence we are entitled to apply the term substance to a phenomenon, only because we

suppose its existence in all time, a notion which the word permanence does not fully express, as it seems

rather to be referable to future time. However, the internal necessity perpetually to be, is inseparably

connected with the necessity always to have been, and so the expression may stand as it is. "Gigni de nihilo

nihil; in nihilum nil posse reverti,"* are two propositions which the ancients never parted, and which people

nowadays sometimes mistakenly disjoin, because they imagine that the propositions apply to objects as

things in themselves, and that the former might be inimical to the dependence (even in respect of its

substance also) of the world upon a supreme cause. But this apprehension is entirely needless, for the

question in this case is only of phenomena in the sphere of experience, the unity of which never could be

possible, if we admitted the possibility that new things (in respect of their substance) should arise. For in that

case, we should lose altogether that which alone can represent the unity of time, to wit, the identity of the

substratum, as that through which alone all change possesses complete and thorough unity. This permanence

is, however, nothing but the manner in which we represent to ourselves the existence of things in the

*[Persius, Satirae, iii.8384. "Nothing can be produced from nothing; nothing can be returned into nothing."]

The determinations of a substance, which are only particular modes of its existence, are called accidents.

They are always real, because they concern the existence of substance (negations are only determinations,

which express the nonexistence of something in the substance). Now, if to this real in the substance we

ascribe a particular existence (for example, to motion as an accident of matter), this existence is called

inherence, in contradistinction to the existence of substance, which we call subsistence. But hence arise many

misconceptions, and it would be a more accurate and just mode of expression to designate the accident only

as the mode in which the existence of a substance is positively determined. Meanwhile, by reason of the

conditions of the logical exercise of our understanding, it is impossible to avoid separating, as it were, that

which in the existence of a substance is subject to change, whilst the substance remains, and regarding it in

relation to that which is properly permanent and radical. On this account, this category of substance stands

under the title of relation, rather because it is the condition thereof than because it contains in itself any

Now, upon this notion of permanence rests the proper notion of the conception change. Origin and extinction

are not changes of that which originates or becomes extinct. Change is but a mode of existence, which

follows on another mode of existence of the same object; hence all that changes is permanent, and only the

condition thereof changes. Now since this mutation affects only determinations, which can have a beginning

or an end, we may say, employing an expression which seems somewhat paradoxical: "Only the permanent

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(substance) is subject to change; the mutable suffers no change, but rather alternation, that is, when certain

Change, when, cannot be perceived by us except in substances, and origin or extinction in an absolute sense,

that does not concern merely a determination of the permanent, cannot be a possible perception, for it is this

very notion of the permanent which renders possible the representation of a transition from one state into

another, and from nonbeing to being, which, consequently, can be empirically cognized only as alternating

determinations of that which is permanent. Grant that a thing absolutely begins to be; we must then have a

point of time in which it was not. But how and by what can we fix and determine this point of time, unless by

that which already exists? For a void time preceding is not an object of perception; but if we connect this

beginning with objects which existed previously, and which continue to exist till the object in question in

question begins to be, then the latter can only be a determination of the former as the permanent. The same

holds good of the notion of extinction, for this presupposes the empirical representation of a time, in which a

Substances (in the world of phenomena) are the substratum of all determinations of time. The beginning of

some, and the ceasing to be of other substances, would utterly do away with the only condition of the

empirical unity of time; and in that case phenomena would relate to two different times, in which, side by

side, existence would pass; which is absurd. For there is only one time in which all different times must be

Accordingly, permanence is a necessary condition under which alone phenomena, as things or objects, are

determinable in a possible experience. But as regards the empirical criterion of this necessary permanence,

and with it of the substantiality of phenomena, we shall find sufficient opportunity to speak in the sequel.

(That all phenomena in the succession of time are only changes, that is, a successive being and nonbeing of

the determinations of substance, which is permanent; consequently that a being of substance itself which

follows on the nonbeing thereof, or a nonbeing of substance which follows on the being thereof, in other

words, that the origin or extinction of substance itself, is impossible all this has been fully established in

treating of the foregoing principle. This principle might have been expressed as follows: "All alteration

(succession) of phenomena is merely change"; for the changes of substance are not origin or extinction,

because the conception of change presupposes the same subject as existing with two opposite determinations,

and consequently as permanent. After this premonition, we shall proceed to the proof.)

I perceive that phenomena succeed one another, that is to say, a state of things exists at one time, the opposite

of which existed in a former state. In this case, then, I really connect together two perceptions in time. Now

connection is not an operation of mere sense and intuition, but is the product of a synthetical faculty of

imagination, which determines the internal sense in respect of a relation of time. But imagination can connect

these two states in two ways, so that either the one or the other may antecede in time; for time in itself cannot

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be an object of perception, and what in an object precedes and what follows cannot be empirically determined

in relation to it. I am only conscious, then, that my imagination places one state before and the other after; not

that the one state antecedes the other in the object. In other words, the objective relation of the successive

phenomena remains quite undetermined by means of mere perception. Now in order that this relation may be

cognized as determined, the relation between the two states must be so cogitated that it is thereby determined

as necessary, which of them must be placed before and which after, and not conversely. But the conception

which carries with it a necessity of synthetical unity, can be none other than a pure conception of the

understanding which does not lie in mere perception; and in this case it is the conception of "the relation of

cause and effect," the former of which determines the latter in time, as its necessary consequence, and not as

something which might possibly antecede (or which might in some cases not be perceived to follow). It

follows that it is only because we subject the sequence of phenomena, and consequently all change, to the law

of causality, that experience itself, that is, empirical cognition of phenomena, becomes possible; and

consequently, that phenomena themselves, as objects of experience, are possible only by virtue of this law.

Our apprehension of the manifold of phenomena is always successive. The representations of parts succeed

one another. Whether they succeed one another in the object also, is a second point for reflection, which was

not contained in the former. Now we may certainly give the name of object to everything, even to every

representation, so far as we are conscious thereof; but what this word may mean in the case of phenomena,

not merely in so far as they (as representations) are objects, but only in so far as they indicate an object, is a

question requiring deeper consideration. In so far as they, regarded merely as representations, are at the same

time objects of consciousness, they are not to be distinguished from apprehension, that is, reception into the

synthesis of imagination, and we must therefore say: "The manifold of phenomena is always produced

successively in the mind." If phenomena were things in themselves, no man would be able to conjecture from

the succession of our representations how this manifold is connected in the object; for we have to do only

with our representations. How things may be in themselves, without regard to the representations through

which they affect us, is utterly beyond the sphere of our cognition. Now although phenomena are not things

in themselves, and are nevertheless the only thing given to us to be cognized, it is my duty to show what sort

of connection in time belongs to the manifold in phenomena themselves, while the representation of this

manifold in apprehension is always successive. For example, the apprehension of the manifold in the

phenomenon of a house which stands before me, is successive. Now comes the question whether the

manifold of this house is in itself successive which no one will be at all willing to grant. But, so soon as I

raise my conception of an object to the transcendental signification thereof, I find that the house is not a thing

in itself, but only a phenomenon, that is, a representation, the transcendental object of which remains utterly

unknown. What then am I to understand by the question: "How can the manifold be connected in the

phenomenon itself not considered as a thing in itself, but merely as a phenomenon?" Here that which lies in

my successive apprehension is regarded as representation, whilst the phenomenon which is given me,

notwithstanding that it is nothing more than a complex of these representations, is regarded as the object

thereof, with which my conception, drawn from the representations of apprehension, must harmonize. It is

very soon seen that, as accordance of the cognition with its object constitutes truth, the question now before

us can only relate to the formal conditions of empirical truth; and that the phenomenon, in opposition to the

representations of apprehension, can only be distinguished therefrom as the object of them, if it is subject to a

rule which distinguishes it from every other apprehension, and which renders necessary a mode of connection

of the manifold. That in the phenomenon which contains the condition of this necessary rule of apprehension,

Let us now proceed to our task. That something happens, that is to say, that something or some state exists

which before was not, cannot be empirically perceived, unless a phenomenon precedes, which does not

contain in itself this state. For a reality which should follow upon a void time, in other words, a beginning,

which no state of things precedes, can just as little be apprehended as the void time itself. Every apprehension

of an event is therefore a perception which follows upon another perception. But as this is the case with all

synthesis of apprehension, as I have shown above in the example of a house, my apprehension of an event is

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not yet sufficiently distinguished from other apprehensions. But I remark also that if in a phenomenon which

contains an occurrence, I call the antecedent state of my perception, A, and the following state, B, the

perception B can only follow A in apprehension, and the perception A cannot follow B, but only precede it.

For example, I see a ship float down the stream of a river. My perception of its place lower down follows

upon my perception of its place higher up the course of the river, and it is impossible that, in the

apprehension of this phenomenon, the vessel should be perceived first below and afterwards higher up the

stream. Here, therefore, the order in the sequence of perceptions in apprehension is determined; and by this

order apprehension is regulated. In the former example, my perceptions in the apprehension of a house might

begin at the roof and end at the foundation, or vice versa; or I might apprehend the manifold in this empirical

intuition, by going from left to right, and from right to left. Accordingly, in the series of these perceptions,

there was no determined order, which necessitated my beginning at a certain point, in order empirically to

connect the manifold. But this rule is always to be met with in the perception of that which happens, and it

makes the order of the successive perceptions in the apprehension of such a phenomenon necessary.

I must, therefore, in the present case, deduce the subjective sequence of apprehension from the objective

sequence of phenomena, for otherwise the former is quite undetermined, and one phenomenon is not

distinguishable from another. The former alone proves nothing as to the connection of the manifold in an

object, for it is quite arbitrary. The latter must consist in the order of the manifold in a phenomenon,

according to which order the apprehension of one thing (that which happens) follows that of another thing

(which precedes), in conformity with a rule. In this way alone can I be authorized to say of the phenomenon

itself, and not merely of my own apprehension, that a certain order or sequence is to be found therein. That is,

In conformity with this rule, then, it is necessary that in that which antecedes an event there be found the

condition of a rule, according to which in this event follows always and necessarily; but I cannot reverse this

and go back from the event, and determine (by apprehension) that which antecedes it. For no phenomenon

goes back from the succeeding point of time to the preceding point, although it does certainly relate to a

preceding point of time; from a given time, on the other hand, there is always a necessary progression to the

determined succeeding time. Therefore, because there certainly is something that follows, I must of necessity

connect it with something else, which antecedes, and upon which it follows, in conformity with a rule, that is

necessarily, so that the event, as conditioned, affords certain indication of a condition, and this condition

Let us suppose that nothing precedes an event, upon which this event must follow in conformity with a rule.

All sequence of perception would then exist only in apprehension, that is to say, would be merely subjective,

and it could not thereby be objectively determined what thing ought to precede, and what ought to follow in

perception. In such a case, we should have nothing but a play of representations, which would possess no

application to any object. That is to say, it would not be possible through perception to distinguish one

phenomenon from another, as regards relations of time; because the succession in the act of apprehension

would always be of the same sort, and therefore there would be nothing in the phenomenon to determine the

succession, and to render a certain sequence objectively necessary. And, in this case, I cannot say that two

states in a phenomenon follow one upon the other, but only that one apprehension follows upon another. But

this is merely subjective, and does not determine an object, and consequently cannot be held to be cognition

Accordingly, when we know in experience that something happens, we always presuppose that something

precedes, whereupon it follows in conformity with a rule. For otherwise I could not say of the object that it

follows; because the mere succession in my apprehension, if it be not determined by a rule in relation to

something preceding, does not authorize succession in the object. Only, therefore, in reference to a rule,

according to which phenomena are determined in their sequence, that is, as they happen, by the preceding

state, can I make my subjective synthesis (of apprehension) objective, and it is only under this presupposition

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No doubt it appears as if this were in thorough contradiction to all the notions which people have hitherto

entertained in regard to the procedure of the human understanding. According to these opinions, it is by

means of the perception and comparison of similar consequences following upon certain antecedent

phenomena that the understanding is led to the discovery of a rule, according to which certain events always

follow certain phenomena, and it is only by this process that we attain to the conception of cause. Upon such

a basis, it is clear that this conception must be merely empirical, and the rule which it furnishes us with

"Everything that happens must have a cause" would be just as contingent as experience itself. The

universality and necessity of the rule or law would be perfectly spurious attributes of it. Indeed, it could not

possess universal validity, inasmuch as it would not in this case be a priori, but founded on deduction. But the

same is the case with this law as with other pure a priori representations (e.g., space and time), which we can

draw in perfect clearness and completeness from experience, only because we had already placed them

therein, and by that means, and by that alone, had rendered experience possible. Indeed, the logical clearness

of this representation of a rule, determining the series of events, is possible only when we have made use

thereof in experience. Nevertheless, the recognition of this rule, as a condition of the synthetical unity of

phenomena in time, was the ground of experience itself and consequently preceded it a priori.

It is now our duty to show by an example that we never, even in experience, attribute to an object the notion

of succession or effect (of an event that is, the happening of something that did not exist before), and

distinguish it from the subjective succession of apprehension, unless when a rule lies at the foundation, which

compels us to observe this order of perception in preference to any other, and that, indeed, it is this necessity

We have representations within us, of which also we can be conscious. But, however widely extended,

however accurate and thoroughgoing this consciousness may be, these representations are still nothing more

than representations, that is, internal determinations of the mind in this or that relation of time. Now how

happens it that to these representations we should set an object, or that, in addition to their subjective reality,

as modifications, we should still further attribute to them a certain unknown objective reality? It is clear that

objective significancy cannot consist in a relation to another representation (of that which we desire to term

object), for in that case the question again arises: "How does this other representation go out of itself, and

obtain objective significancy over and above the subjective, which is proper to it, as a determination of a state

of mind?" If we try to discover what sort of new property the relation to an object gives to our subjective

representations, and what new importance they thereby receive, we shall find that this relation has no other

effect than that of rendering necessary the connection of our representations in a certain manner, and of

subjecting them to a rule; and that conversely, it is only because a certain order is necessary in the relations of

In the synthesis of phenomena, the manifold of our representations is always successive. Now hereby is not

represented an object, for by means of this succession, which is common to all apprehension, no one thing is

distinguished from another. But so soon as I perceive or assume that in this succession there is a relation to a

state antecedent, from which the representation follows in accordance with a rule, so soon do I represent

something as an event, or as a thing that happens; in other words, I cognize an object to which I must assign a

certain determinate position in time, which cannot be altered, because of the preceding state in the object.

When, therefore, I perceive that something happens, there is contained in this representation, in the first

place, the fact, that something antecedes; because, it. is only in relation to this that the phenomenon obtains

its proper relation of time, in other words, exists after an antecedent time, in which it did not exist. But it can

receive its determined place in time only by the presupposition that something existed in the foregoing state,

upon which it follows inevitably and always, that is, in conformity with a rule. From all this it is evident that,

in the first place, I cannot reverse the order of succession, and make that which happens precede that upon

which it follows; and that, in the second place, if the antecedent state be posited, a certain determinate event

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inevitably and necessarily follows. Hence it follows that there exists a certain order in our representations,

whereby the present gives a sure indication of some previously existing state, as a correlate, though still

undetermined, of the existing event which is given a correlate which itself relates to the event as its

consequence, conditions it, and connects it necessarily with itself in the series of time.

If then it be admitted as a necessary law of sensibility, and consequently a formal condition of all perception,

that the preceding necessarily determines the succeeding time (inasmuch as I cannot arrive at the succeeding

except through the preceding), it must likewise be an indispensable law of empirical representation of the

series of time that the phenomena of the past determine all phenomena in the succeeding time, and that the

latter, as events, cannot take place, except in so far as the former determine their existence in time, that is to

say, establish it according to a rule. For it is of course only in phenomena that we can empirically cognize this

For all experience and for the possibility of experience, understanding is indispensable, and the first step

which it takes in this sphere is not to render the representation of objects clear, but to render the

representation of an object in general, possible. It does this by applying the order of time to phenomena, and

their existence. In other words, it assigns to each phenomenon, as a consequence, a place in relation to

preceding phenomena, determined a priori in time, without which it could not harmonize with time itself,

which determines a place a priori to all its parts. This determination of place cannot be derived from the

relation of phenomena to absolute time (for it is not an object of perception); but, on the contrary, phenomena

must reciprocally determine the places in time of one another, and render these necessary in the order of time.

In other words, whatever follows or happens, must follow in conformity with a universal rule upon that which

was contained in the foregoing state. Hence arises a series of phenomena, which, by means of the

understanding, produces and renders necessary exactly the same order and continuous connection in the

series of our possible perceptions, as is found a priori in the form of internal intuition (time), in which all our

That something happens, then, is a perception which belongs to a possible experience, which becomes real

only because I look upon the phenomenon as determined in regard to its place in time, consequently as an

object, which can always be found by means of a rule in the connected series of my perceptions. But this rule

of the determination of a thing according to succession in time is as follows: "In what precedes may be found

the condition, under which an event always (that is, necessarily) follows." From all this it is obvious that the

principle of cause and effect is the principle of possible experience, that is, of objective cognition of

The proof of this fundamental proposition rests entirely on the following momenta of argument. To all

empirical cognition belongs the synthesis of the manifold by the imagination, a synthesis which is always

successive, that is, in which the representations therein always follow one another. But the order of

succession in imagination is not determined, and the series of successive representations may be taken

retrogressively as well as progressively. But if this synthesis is a synthesis of apprehension (of the manifold

of a given phenomenon),then the order is determined in the object, or to speak more accurately, there is

therein an order of successive synthesis which determines an object, and according to which something

necessarily precedes, and when this is posited, something else necessarily follows. If, then, my perception is

to contain the cognition of an event, that is, of something which really happens, it must be an empirical

judgement, wherein we think that the succession is determined; that is, it presupposes another phenomenon,

upon which this event follows necessarily, or in conformity with a rule. If, on the contrary, when I posited the

antecedent, the event did not necessarily follow, I should be obliged to consider it merely as a subjective play

of my imagination, and if in this I represented to myself anything as objective, I must look upon it as a mere

dream. Thus, the relation of phenomena (as possible perceptions), according to which that which happens is,

as to its existence, necessarily determined in time by something which antecedes, in conformity with a rule

in other words, the relation of cause and effect is the condition of the objective validity of our empirical

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judgements in regard to the sequence of perceptions, consequently of their empirical truth, and therefore of

experience. The principle of the relation of causality in the succession of phenomena is therefore valid for all

objects of experience, because it is itself the ground of the possibility of experience.

Here, however, a difficulty arises, which must be resolved. The principle of the connection of causality

among phenomena is limited in our formula to the succession thereof, although in practice we find that the

principle applies also when the phenomena exist together in the same time, and that cause and effect may be

simultaneous. For example, there is heat in a room, which does not exist in the open air. I look about for the

cause, and find it to be the fire, Now the fire as the cause is simultaneous with its effect, the heat of the room.

In this case, then, there is no succession as regards time, between cause and effect, but they are simultaneous;

and still the law holds good. The greater part of operating causes in nature are simultaneous with their effects,

and the succession in time of the latter is produced only because the cause cannot achieve the total of its

effect in one moment. But at the moment when the effect first arises, it is always simultaneous with the

causality of its cause, because, if the cause had but a moment before ceased to be, the effect could not have

arisen. Here it must be specially remembered that we must consider the order of time and not the lapse

thereof. The relation remains, even though no time has elapsed. The time between the causality of the cause

and its immediate effect may entirely vanish, and the cause and effect be thus simultaneous, but the relation

of the one to the other remains always determinable according to time. If, for example, I consider a leaden

ball, which lies upon a cushion and makes a hollow in it, as a cause, then it is simultaneous with the effect.

But I distinguish the two through the relation of time of the dynamical connection of both. For if I lay the ball

upon the cushion, then the hollow follows upon the before smooth surface; but supposing the cushion has,

from some cause or another, a hollow, there does not thereupon follow a leaden ball.

Thus, the law of succession of time is in all instances the only empirical criterion of effect in relation to the

causality of the antecedent cause. The glass is the cause of the rising of the water above its horizontal surface,

although the two phenomena are contemporaneous. For, as soon as I draw some water with the glass from a

larger vessel, an effect follows thereupon, namely, the change of the horizontal state which the water had in

This conception of causality leads us to the conception of action; that of action, to the conception of force;

and through it, to the conception of substance. As I do not wish this critical essay, the sole purpose of which

is to treat of the sources of our synthetical cognition a priori, to be crowded with analyses which merely

explain, but do not enlarge the sphere of our conceptions, I reserve the detailed explanation of the above

conceptions for a future system of pure reason. Such an analysis, indeed, executed with great particularity,

may already be found in wellknown works on this subject. But I cannot at present refrain from making a

few remarks on the empirical criterion of a substance, in so far as it seems to be more evident and more easily

recognized through the conception of action than through that of the permanence of a phenomenon.

Where action (consequently activity and force) exists, substance also must exist, and in it alone must be

sought the seat of that fruitful source of phenomena. Very well. But if we are called upon to explain what we

mean by substance, and wish to avoid the vice of reasoning in a circle, the answer is by no means so easy.

How shall we conclude immediately from the action to the permanence of that which acts, this being

nevertheless an essential and peculiar criterion of substance (phenomenon)? But after what has been said

above, the solution of this question becomes easy enough, although by the common mode of procedure

merely analysing our conceptions it would be quite impossible. The conception of action indicates the

relation of the subject of causality to the effect. Now because all effect consists in that which happens,

therefore in the changeable, the last subject thereof is the permanent, as the substratum of all that changes,

that is, substance. For according to the principle of causality, actions are always the first ground of all change

in phenomena and, consequently, cannot be a property of a subject which itself changes, because if this were

the case, other actions and another subject would be necessary to determine this change. From all this it

results that action alone, as an empirical criterion, is a sufficient proof of the presence of substantiality,

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without any necessity on my part of endeavouring to discover the permanence of substance by a comparison.

Besides, by this mode of induction we could not attain to the completeness which the magnitude and strict

universality of the conception requires. For that the primary subject of the causality of all arising and passing

away, all origin and extinction, cannot itself (in the sphere of phenomena) arise and pass away, is a sound and

safe conclusion, a conclusion which leads us to the conception of empirical necessity and permanence in

When something happens, the mere fact of the occurrence, without regard to that which occurs, is an object

requiring investigation. The transition from the nonbeing of a state into the existence of it, supposing that

this state contains no quality which previously existed in the phenomenon, is a fact of itself demanding

inquiry. Such an event, as has been shown in No. A, does not concern substance (for substance does not thus

originate), but its condition or state. It is therefore only change, and not origin from nothing. If this origin be

regarded as the effect of a foreign cause, it is termed creation, which cannot be admitted as an event among

phenomena, because the very possibility of it would annihilate the unity of experience. If, however, I regard

all things not as phenomena, but as things in themselves and objects of understanding alone, they, although

substances, may be considered as dependent, in respect of their existence, on a foreign cause. But this would

require a very different meaning in the words, a meaning which could not apply to phenomena as objects of

How a thing can be changed, how it is possible that upon one state existing in one point of time, an opposite

state should follow in another point of time of this we have not the smallest conception a priori. There is

requisite for this the knowledge of real powers, which can only be given empirically; for example, knowledge

of moving forces, or, in other words, of certain successive phenomena (as movements) which indicate the

presence of such forces. But the form of every change, the condition under which alone it can take place as

the coming into existence of another state (be the content of the change, that is, the state which is changed,

what it may), and consequently the succession of the states themselves can very well be considered a priori,

*It must be remarked that I do not speak of the change of certain relations, but of the change of the state.

Thus, when a body moves in a uniform manner, it does not change its state (of motion); but only when all

When a substance passes from one state, a, into another state, b, the point of time in which the latter exists is

different from, and subsequent to that in which the former existed. In like manner, the second state, as reality

(in the phenomenon), differs from the first, in which the reality of the second did not exist, as b from zero.

That is to say, if the state, b, differs from the state, a, only in respect to quantity, the change is a coming into

existence of b a, which in the former state did not exist, and in relation to which that state is = O.

Now the question arises how a thing passes from one state = a, into another state = b. Between two moments

there is always a certain time, and between two states existing in these moments there is always a difference

having a certain quantity (for all parts of phenomena are in their turn quantities). Consequently, every

transition from one state into another is always effected in a time contained between two moments, of which

the first determines the state which leaves, and the second determines the state into the thing passes. the thing

leaves, and the second determines the state into which the thing Both moments, then, are limitations of the

time of a change, consequently of the intermediate state between both, and as such they belong to the total of

the change. Now every change has a cause, which evidences its causality in the whole time during which the

charge takes place. The cause, therefore, does not produce the change all at once or in one moment, but in a

time, so that, as the time gradually increases from the commencing instant, a, to its completion at b, in like

manner also, the quantity of the reality (b a) is generated through the lesser degrees which are contained

between the first and last. All change is therefore possible only through a continuous action of the causality,

which, in so far as it is uniform, we call a momentum. The change does not consist of these momenta, but is

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Such is the law of the continuity of all change, the ground of which is that neither time itself nor any

phenomenon in time consists of parts which are the smallest possible, but that, notwithstanding, the state of a

thing passes in the process of a change through all these parts, as elements, to its second state. There is no

smallest degree of reality in a phenomenon, just as there is no smallest degree in the quantity of time; and so

the new state of reality grows up out of the former state, through all the infinite degrees thereof, the

differences of which one from another, taken all together, are less than the difference between o and a.

It is not our business to inquire here into the utility of this principle in the investigation of nature. But how

such a proposition, which appears so greatly to extend our knowledge of nature, is possible completely a

priori, is indeed a question which deserves investigation, although the first view seems to demonstrate the

truth and reality of the principle, and the question, how it is possible, may be considered superfluous. For

there are so many groundless pretensions to the enlargement of our knowledge by pure reason that we must

take it as a general rule to be mistrustful of all such, and without a thoroughgoing and radical deduction, to

Every addition to our empirical knowledge, and every advance made in the exercise of our perception, is

nothing more than an extension of the determination of the internal sense, that is to say, a progression in time,

be objects themselves what they may, phenomena, or pure intuitions. This progression in time determines

everything, and is itself determined by nothing else. That is to say, the parts of the progression exist only in

time, and by means of the synthesis thereof, and are not given antecedently to it. For this reason, every

transition in perception to anything which follows upon another in time, is a determination of time by means

of the production of this perception. And as this determination of time is, always and in all its parts, a

quantity, the perception produced is to be considered as a quantity which proceeds through all its degrees no

one of which is the smallest possible from zero up to its determined degree. From this we perceive the

possibility of cognizing a priori a law of changes a law, however, which concerns their form merely. We

merely anticipate our own apprehension, the formal condition of which, inasmuch as it is itself to be found in

the mind antecedently to all given phenomena, must certainly be capable of being cognized a priori.

Thus, as time contains the sensuous condition a priori of the possibility of a continuous progression of that

which exists to that which follows it, the understanding, by virtue of the unity of apperception, contains the

condition a priori of the possibility of a continuous determination of the position in time of all phenomena,

and this by means of the series of causes and effects, the former of which necessitate the sequence of the

latter, and thereby render universally and for all time, and by consequence, objectively, valid the empirical

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 91

Things are coexistent, when in empirical intuition the perception of the one can follow upon the perception of

the other, and vice versa which cannot occur in the succession of phenomena, as we have shown in the

explanation of the second principle. Thus I can perceive the moon and then the earth, or conversely, first the

earth and then the moon; and for the reason that my perceptions of these objects can reciprocally follow each

other, I say, they exist contemporaneously. Now coexistence is the existence of the manifold in the same

time. But time itself is not an object of perception; and therefore we cannot conclude from the fact that things

are placed in the same time, the other fact, that the perception of these things can follow each other

reciprocally. The synthesis of the imagination in apprehension would only present to us each of these

perceptions as present in the subject when the other is not present, and contrariwise; but would not show that

the objects are coexistent, that is to say, that, if the one exists, the other also exists in the same time, and that

this is necessarily so, in order that the perceptions may be capable of following each other reciprocally. It

follows that a conception of the understanding or category of the reciprocal sequence of the determinations of

phenomena (existing, as they do, apart from each other, and yet contemporaneously), is requisite to justify us

in saying that the reciprocal succession of perceptions has its foundation in the object, and to enable us to

represent coexistence as objective. But that relation of substances in which the one contains determinations

the ground of which is in the other substance, is the relation of influence. And, when this influence is

reciprocal, it is the relation of community or reciprocity. Consequently the coexistence of substances in space

cannot be cognized in experience otherwise than under the precondition of their reciprocal action. This is

therefore the condition of the possibility of things themselves as objects of experience.

Things are coexistent, in so far as they exist in one and the same time. But how can we know that they exist

in one and the same time? Only by observing that the order in the synthesis of apprehension of the manifold

is arbitrary and a matter of indifference, that is to say, that it can proceed from A, through B, C, D, to E, or

contrariwise from E to A. For if they were successive in time (and in the order, let us suppose, which begins

with A), it is quite impossible for the apprehension in perception to begin with E and go backwards to A,

inasmuch as A belongs to past time and, therefore, cannot be an object of apprehension.

Let us assume that in a number of substances considered as phenomena each is completely isolated, that is,

that no one acts upon another. Then I say that the coexistence of these cannot be an object of possible

perception and that the existence of one cannot, by any mode of empirical synthesis, lead us to the existence

of another. For we imagine them in this case to be separated by a completely void space, and thus perception,

which proceeds from the one to the other in time, would indeed determine their existence by means of a

following perception, but would be quite unable to distinguish whether the one phenomenon follows

Besides the mere fact of existence, then, there must be something by means of which A determines the

position of B in time and, conversely, B the position of A; because only under this condition can substances

be empirically represented as existing contemporaneously. Now that alone determines the position of another

thing in time which is the cause of it or of its determinations. Consequently every substance (inasmuch as it

can have succession predicated of it only in respect of its determinations) must contain the causality of certain

determinations in another substance, and at the same time the effects of the causality of the other in itself.

That is to say, substances must stand (mediately or immediately) in dynamical community with each other, if

coexistence is to be cognized in any possible experience. But, in regard to objects of experience, that is

absolutely necessary without which the experience of these objects would itself be impossible. Consequently

it is absolutely necessary that all substances in the world of phenomena, in so far as they are coexistent, stand

The word community has in our language* two meanings, and contains the two notions conveyed in the Latin

communio and commercium. We employ it in this place in the latter sense that of a dynamical community,

without which even the community of place (communio spatii) could not be empirically cognized. In our

experiences it is easy to observe that it is only the continuous influences in all parts of space that can conduct

SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding. 92

our senses from one object to another; that the light which plays between our eyes and the heavenly bodies

produces a mediating community between them and us, and thereby evidences their coexistence with us; that

we cannot empirically change our position (perceive this change), unless the existence of matter throughout

the whole of space rendered possible the perception of the positions we occupy; and that this perception can

prove the contemporaneous existence of these places only through their reciprocal influence, and thereby also

the coexistence of even the most remote objects although in this case the proof is only mediate. Without

community, every perception (of a phenomenon in space) is separated from every other and isolated, and the

chain of empirical representations, that is, of experience, must, with the appearance of a new object, begin

entirely de novo, without the least connection with preceding representations, and without standing towards

these even in the relation of time. My intention here is by no means to combat the notion of empty space; for

it may exist where our perceptions cannot exist, inasmuch as they cannot reach thereto, and where, therefore,

no empirical perception of coexistence takes place. But in this case it is not an object of possible experience.

The following remarks may be useful in the way of explanation. In the mind, all phenomena, as contents of a

possible experience, must exist in community (communio) of apperception or consciousness, and in so far as

it is requisite that objects be represented as coexistent and connected, in so far must they reciprocally

determine the position in time of each other and thereby constitute a whole. If this subjective community is to

rest upon an objective basis, or to be applied to substances as phenomena, the perception of one substance

must render possible the perception of another, and conversely. For otherwise succession, which is always

found in perceptions as apprehensions, would be predicated of external objects, and their representation of

their coexistence be thus impossible. But this is a reciprocal influence, that is to say, a real community

(commercium) of substances, without which therefore the empirical relation of coexistence would be a notion

beyond the reach of our minds. By virtue of this commercium, phenomena, in so far as they are apart from,

and nevertheless in connection with each other, constitute a compositum reale. Such composita are possible

in many different ways. The three dynamical relations then, from which all others spring, are those of

These, then, are the three analogies of experience. They are nothing more than principles of the determination

of the existence of phenomena in time, according to the three modi of this determination; to wit, the relation

to time itself as a quantity (the quantity of existence, that is, duration), the relation in time as a series or

succession, finally, the relation in time as the complex of all existence (simultaneity). This unity of

determination in regard to time is thoroughly dynamical; that is to say, time is not considered as that in which

experience determines immediately to every existence its position; for this is impossible, inasmuch as

absolute time is not an object of perception, by means of which phenomena can be connected with each other.

On the contrary, the rule of the understanding, through which alone the existence of phenomena can receive

synthetical unity as regards relations of time, determines for every phenomenon its position in time, and

By nature, in the empirical sense of the word, we understand the totality of phenomena connected, in respect

of their existence, according to necessary rules, that is, laws. There are therefore certain laws (which are

moreover a priori) which make nature possible; and all empirical laws can exist only by means of experience,

and by virtue of those primitive laws through which experience itself becomes possible. The purpose of the

analogies is therefore to represent to us the unity of nature in the connection of all phenomena under certain

exponents, the only business of which is to express the relation of time (in so far as it contains all existence in

itself) to the unity of apperception, which can exist in synthesis only according to rules. The combined

expression of all is this: "All phenomena exist in one nature, and must so exist, inasmuch as without this a

priori unity, no unity of experience, and consequently no determination of objects in experience, is possible."

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As regards the mode of proof which we have employed in treating of these transcendental laws of nature, and

the peculiar character of we must make one remark, which will at the same time be important as a guide in

every other attempt to demonstrate the truth of intellectual and likewise synthetical propositions a priori. Had

we endeavoured to prove these analogies dogmatically, that is, from conceptions; that is to say, had we

employed this method in attempting to show that everything which exists, exists only in that which is

permanent that every thing or event presupposes the existence of something in a preceding state, upon

which it follows in conformity with a rule lastly, that in the manifold, which is coexistent, the states coexist

in connection with each other according to a rule all our labour would have been utterly in vain. For more

conceptions of things, analyse them as we may, cannot enable us to conclude from the existence of one object

to the existence of another. What other course was left for us to pursue? This only, to demonstrate the

possibility of experience as a cognition in which at last all objects must be capable of being presented to us, if

the representation of them is to possess any objective reality. Now in this third, this mediating term, the

essential form of which consists in the synthetical unity of the apperception of all phenomena, we found a

priori conditions of the universal and necessary determination as to time of all existences in the world of

phenomena, without which the empirical determination thereof as to time would itself be impossible, and we

also discovered rules of synthetical unity a priori, by means of which we could anticipate experience. For

want of this method, and from the fancy that it was possible to discover a dogmatical proof of the synthetical

propositions which are requisite in the empirical employment of the understanding, has it happened that a

proof of the principle of sufficient reason has been so often attempted, and always in vain. The other two

analogies nobody has ever thought of, although they have always been silently employed by the mind,*

because the guiding thread furnished by the categories was wanting, the guide which alone can enable us to

*The unity of the universe, in which all phenomena to be connected, is evidently a mere consequence of the

admitted principle of the community of all substances which are coexistent. For were substances isolated,

they could not as parts constitute a whole, and were their connection (reciprocal action of the manifold) not

necessary from the very fact of coexistence, we could not conclude from the fact of the latter as a merely

ideal relation to the former as a real one. We have, however, shown in its place that community is the proper

ground of the possibility of an empirical cognition of coexistence, and that we may therefore properly reason

1. That which agrees with the formal conditions (intuition and conception) of experience, is possible.

2. That which coheres with the material conditions of experience (sensation), is real.

3. That whose coherence with the real is determined according to universal conditions of experience is

The categories of modality possess this peculiarity, that they do not in the least determine the object, or

enlarge the conception to which they are annexed as predicates, but only express its relation to the faculty of

cognition. Though my conception of a thing is in itself complete, I am still entitled to ask whether the object

of it is merely possible, or whether it is also real, or, if the latter, whether it is also necessary. But hereby the

object itself is not more definitely determined in thought, but the question is only in what relation it,

including all its determinations, stands to the understanding and its employment in experience, to the

empirical faculty of judgement, and to the reason of its application to experience.

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For this very reason, too, the categories of modality are nothing more than explanations of the conceptions of

possibility, reality, and necessity, as employed in experience, and at the same time, restrictions of all the

categories to empirical use alone, not authorizing the transcendental employment of them. For if they are to

have something more than a merely logical significance, and to be something more than a mere analytical

expression of the form of thought, and to have a relation to things and their possibility, reality, or necessity,

they must concern possible experience and its synthetical unity, in which alone objects of cognition can be

The postulate of the possibility of things requires also, that the conception of the things agree with the formal

conditions of our experience in general. But this, that is to say, the objective form of experience, contains all

the kinds of synthesis which are requisite for the cognition of objects. A conception which contains a

synthesis must be regarded as empty and, without reference to an object, if its synthesis does not belong to

experience either as borrowed from it, and in this case it is called an empirical conception, or such as is the

ground and a priori condition of experience (its form), and in this case it is a pure conception, a conception

which nevertheless belongs to experience, inasmuch as its object can be found in this alone. For where shall

we find the criterion or character of the possibility of an object which is cogitated by means of an a priori

synthetical conception, if not in the synthesis which constitutes the form of empirical cognition of objects?

That in such a conception no contradiction exists is indeed a necessary logical condition, but very far from

being sufficient to establish the objective reality of the conception, that is, the possibility of such an object as

is thought in the conception. Thus, in the conception of a figure which is contained within two straight lines,

there is no contradiction, for the conceptions of two straight lines and of their junction contain no negation of

a figure. The impossibility in such a case does not rest upon the conception in itself, but upon the

construction of it in space, that is to say, upon the conditions of space and its determinations. But these have

themselves objective reality, that is, they apply to possible things, because they contain a priori the form of

And now we shall proceed to point out the extensive utility and influence of this postulate of possibility.

When I represent to myself a thing that is permanent, so that everything in it which changes belongs merely

to its state or condition, from such a conception alone I never can cognize that such a thing is possible. Or, if I

represent to myself something which is so constituted that, when it is posited, something else follows always

and infallibly, my thought contains no selfcontradiction; but whether such a property as causality is to be

found in any possible thing, my thought alone affords no means of judging. Finally, I can represent to myself

different things (substances) which are so constituted that the state or condition of one causes a change in the

state of the other, and reciprocally; but whether such a relation is a property of things cannot be perceived

from these conceptions, which contain a merely arbitrary synthesis. Only from the fact, therefore, that these

conceptions express a priori the relations of perceptions in every experience, do we know that they possess

objective reality, that is, transcendental truth; and that independent of experience, though not independent of

all relation to form of an experience in general and its synthetical unity, in which alone objects can be

But when we fashion to ourselves new conceptions of substances, forces, action, and reaction, from the

material presented to us by perception, without following the example of experience in their connection, we

create mere chimeras, of the possibility of which we cannot discover any criterion, because we have not taken

experience for our instructress, though we have borrowed the conceptions from her. Such fictitious

conceptions derive their character of possibility not, like the categories, a priori, as conceptions on which all

experience depends, but only, a posteriori, as conceptions given by means of experience itself, and their

possibility must either be cognized a posteriori and empirically, or it cannot be cognized at all. A substance

which is permanently present in space, yet without filling it (like that tertium quid between matter and the

thinking subject which some have tried to introduce into metaphysics), or a peculiar fundamental power of

the mind of intuiting the future by anticipation (instead of merely inferring from past and present events), or,

finally, a power of the mind to place itself in community of thought with other men, however distant they

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may be these are conceptions the possibility of which has no ground to rest upon. For they are not based

upon experience and its known laws; and, without experience, they are a merely arbitrary conjunction of

thoughts, which, though containing no internal contradiction, has no claim to objective reality, neither,

consequently, to the possibility of such an object as is thought in these conceptions. As far as concerns

reality, it is selfevident that we cannot cogitate such a possibility in concreto without the aid of experience;

because reality is concerned only with sensation, as the matter of experience, and not with the form of

But I pass by everything which derives its possibility from reality in experience, and I purpose treating here

merely of the possibility of things by means of a priori conceptions. I maintain, then, that the possibility of

things is not derived from such conceptions per se, but only when considered as formal and objective

It seems, indeed, as if the possibility of a triangle could be cognized from the conception of it alone (which is

certainly independent of experience); for we can certainly give to the conception a corresponding object

completely a priori, that is to say, we can construct it. But as a triangle is only the form of an object, it must

remain a mere product of the imagination, and the possibility of the existence of an object corresponding to it

must remain doubtful, unless we can discover some other ground, unless we know that the figure can be

cogitated under the conditions upon which all objects of experience rest. Now, the facts that space is a formal

condition a priori of external experience, that the formative synthesis, by which we construct a triangle in

imagination, is the very same as that we employ in the apprehension of a phenomenon for the purpose of

making an empirical conception of it, are what alone connect the notion of the possibility of such a thing,

with the conception of it. In the same manner, the possibility of continuous quantities, indeed of quantities in

general, for the conceptions of them are without exception synthetical, is never evident from the conceptions

in themselves, but only when they are considered as the formal conditions of the determination of objects in

experience. And where, indeed, should we look for objects to correspond to our conceptions, if not in

experience, by which alone objects are presented to us? It is, however, true that without antecedent

experience we can cognize and characterize the possibility of things, relatively to the formal conditions,

under which something is determined in experience as an object, consequently, completely a priori. But still

The postulate concerning the cognition of the reality of things requires perception, consequently conscious

sensation, not indeed immediately, that is, of the object itself, whose existence is to be cognized, but still that

the object have some connection with a real perception, in accordance with the analogies of experience,

From the mere conception of a thing it is impossible to conclude its existence. For, let the conception be ever

so complete, and containing a statement of all the determinations of the thing, the existence of it has nothing

to do with all this, but only with thew question whether such a thing is given, so that the perception of it can

in every case precede the conception. For the fact that the conception of it precedes the perception, merely

indicates the possibility of its existence; it is perception which presents matter to the conception, that is the

sole criterion of reality. Prior to the perception of the thing, however, and therefore comparatively a priori, we

are able to cognize its existence, provided it stands in connection with some perceptions according to the

principles of the empirical conjunction of these, that is, in conformity with the analogies of perception. For,

in this case, the existence of the supposed thing is connected with our perception in a possible experience,

and we are able, with the guidance of these analogies, to reason in the series of possible perceptions from a

thing which we do really perceive to the thing we do not perceive. Thus, we cognize the existence of a

magnetic matter penetrating all bodies from the perception of the attraction of the steelfilings by the magnet,

although the constitution of our organs renders an immediate perception of this matter impossible for us. For,

according to the laws of sensibility and the connected context of our perceptions, we should in an experience

come also on an immediate empirical intuition of this matter, if our senses were more acute but this

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obtuseness has no influence upon and cannot alter the form of possible experience in general. Our knowledge

of the existence of things reaches as far as our perceptions, and what may be inferred from them according to

empirical laws, extend. If we do not set out from experience, or do not proceed according to the laws of the

empirical connection of phenomena, our pretensions to discover the existence of a thing which we do not

immediately perceive are vain. Idealism, however, brings forward powerful objections to these rules for

proving existence mediately. This is, therefore, the proper place for its refutation.

Idealism I mean material idealism is the theory which declares the existence of objects in space without us

to be either () doubtful and indemonstrable, or (2) false and impossible. The first is the problematical idealism

of Descartes, who admits the undoubted certainty of only one empirical assertion (assertio), to wit, "I am."

The second is the dogmatical idealism of Berkeley, who maintains that space, together with all the objects of

which it is the inseparable condition, is a thing which is in itself impossible, and that consequently the objects

in space are mere products of the imagination. The dogmatical theory of idealism is unavoidable, if we regard

space as a property of things in themselves; for in that case it is, with all to which it serves as condition, a

nonentity. But the foundation for this kind of idealism we have already destroyed in the transcendental

aesthetic. Problematical idealism, which makes no such assertion, but only alleges our incapacity to prove the

existence of anything besides ourselves by means of immediate experience, is a theory rational and

evidencing a thorough and philosophical mode of thinking, for it observes the rule not to form a decisive

judgement before sufficient proof be shown. The desired proof must therefore demonstrate that we have

experience of external things, and not mere fancies. For this purpose, we must prove, that our internal and, to

Descartes, indubitable experience is itself possible only under the previous assumption of external

I am conscious of my own existence as determined in time. All determination in regard to time presupposes

the existence of something permanent in perception. But this permanent something cannot be something in

me, for the very reason that my existence in time is itself determined by this permanent something. It follows

that the perception of this permanent existence is possible only through a thing without me and not through

the mere representation of a thing without me. Consequently, the determination of my existence in time is

possible only through the existence of real things external to me. Now, consciousness in time is necessarily

connected with the consciousness of the possibility of this determination in time. Hence it follows that

consciousness in time is necessarily connected also with the existence of things without me, inasmuch as the

existence of these things is the condition of determination in time. That is to say, the consciousness of my

own existence is at the same time an immediate consciousness of the existence of other things without me.

Remark I. The reader will observe, that in the foregoing proof the game which idealism plays is retorted upon

itself, and with more justice. It assumed that the only immediate experience is internal and that from this we

can only infer the existence of external things. But, as always happens, when we reason from given effects to

determined causes, idealism bas reasoned with too much haste and uncertainty, for it is quite possible that the

cause of our representations may lie in ourselves, and that we ascribe it falsely to external things. But our

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proof shows that external experience is properly immediate,* that only by virtue of it not, indeed, the

consciousness of our own existence, but certainly the determination of our existence in time, that is, internal

experience is possible. It is true, that the representation "I am," which is the expression of the consciousness

which can accompany all my thoughts, is that which immediately includes the existence of a subject. But in

this representation we cannot find any knowledge of the subject, and therefore also no empirical knowledge,

that is, experience. For experience contains, in addition to the thought of something existing, intuition, and in

this case it must be internal intuition, that is, time, in relation to which the subject must be determined. But

the existence of external things is absolutely requisite for this purpose, so that it follows that internal

*The immediate consciousness of the existence of external things is, in the preceding theorem, not

presupposed, but proved, by the possibility of this consciousness understood by us or not. The question as to

the possibility of it would stand thus: "Have we an internal sense, but no external sense, and is our belief in

external perception a mere delusion?" But it is evident that, in order merely to fancy to ourselves anything as

external, that is, to present it to the sense in intuition we must already possess an external sense, and must

thereby distinguish immediately the mere receptivity of an external intuition from the spontaneity which

characterizes every act of imagination. For merely to imagine also an external sense, would annihilate the

Remark II. Now with this view all empirical use of our faculty of cognition in the determination of time is in

perfect accordance. Its truth is supported by the fact that it is possible to perceive a determination of time

only by means of a change in external relations (motion) to the permanent in space (for example, we become

aware of the sun's motion by observing the changes of his relation to the objects of this earth). But this is not

all. We find that we possess nothing permanent that can correspond and be submitted to the conception of a

substance as intuition, except matter. This idea of permanence is not itself derived from external experience,

but is an a priori necessary condition of all determination of time, consequently also of the internal sense in

reference to our own existence, and that through the existence of external things. In the representation "I," the

consciousness of myself is not an intuition, but a merely intellectual representation produced by the

spontaneous activity of a thinking subject. It follows, that this "I" has not any predicate of intuition, which, in

its character of permanence, could serve as correlate to the determination of time in the internal sense in the

same way as impenetrability is the correlate of matter as an empirical intuition.

Remark III. From the fact that the existence of external things is a necessary condition of the possibility of a

determined consciousness of ourselves, it does not follow that every intuitive representation of external things

involves the existence of these things, for their representations may very well be the mere products of the

imagination (in dreams as well as in madness); though, indeed, these are themselves created by the

reproduction of previous external perceptions, which, as has been shown, are possible only through the reality

of external objects. The sole aim of our remarks has, however, been to prove that internal experience in

general is possible only through external experience in general. Whether this or that supposed experience be

purely imaginary must be discovered from its particular determinations and by comparing these with the

Finally, as regards the third postulate, it applies to material necessity in existence, and not to merely formal

and logical necessity in the connection of conceptions. Now as we cannot cognize completely a priori the

existence of any object of sense, though we can do so comparatively a priori, that is, relatively to some other

previously given existence a cognition, however, which can only be of such an existence as must be

contained in the complex of experience, of which the previously given perception is a part the necessity of

existence can never be cognized from conceptions, but always, on the contrary, from its connection with that

which is an object of perception. But the only existence cognized, under the condition of other given

phenomena, as necessary, is the existence of effects from given causes in conformity with the laws of

causality. It is consequently not the necessity of the existence of things (as substances), but the necessity of

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the state of things that we cognize, and that not immediately, but by means of the existence of other states

given in perception, according to empirical laws of causality. Hence it follows that the criterion of necessity

is to be found only in the law of possible experience that everything which happens is determined a priori in

the phenomenon by its cause. Thus we cognize only the necessity of effects in nature, the causes of which are

given us. Moreover, the criterion of necessity in existence possesses no application beyond the field of

possible experience, and even in this it is not valid of the existence of things as substances, because these can

never be considered as empirical effects, or as something that happens and has a beginning. Necessity,

therefore, regards only the relations of phenomena according to the dynamical law of causality, and the

possibility grounded thereon, of reasoning from some given existence (of a cause) a priori to another

existence (of an effect). "Everything that happens is hypothetically necessary," is a principle which subjects

the changes that take place in the world to a law, that is, to a rule of necessary existence, without which

nature herself could not possibly exist. Hence the proposition, "Nothing happens by blind chance (in mundo

non datur casus)," is an a priori law of nature. The case is the same with the proposition, "Necessity in nature

is not blind," that is, it is conditioned, consequently intelligible necessity (non datur fatum). Both laws subject

the play of change to "a nature of things (as phenomena)," or, which is the same thing, to the unity of the

understanding, and through the understanding alone can changes belong to an experience, as the synthetical

unity of phenomena. Both belong to the class of dynamical principles. The former is properly a consequence

of the principle of causality one of the analogies of experience. The latter belongs to the principles of

modality, which to the determination of causality adds the conception of necessity, which is itself, however,

subject to a rule of the understanding. The principle of continuity forbids any leap in the series of phenomena

regarded as changes (in mundo non datur saltus); and likewise, in the complex of all empirical intuitions in

space, any break or hiatus between two phenomena (non datur hiatus) for we can so express the principle,

that experience can admit nothing which proves the existence of a vacuum, or which even admits it as a part

of an empirical synthesis. For, as regards a vacuum or void, which we may cogitate as out and beyond the

field of possible experience (the world), such a question cannot come before the tribunal of mere

understanding, which decides only upon questions that concern the employment of given phenomena for the

construction of empirical cognition. It is rather a problem for ideal reason, which passes beyond the sphere of

a possible experience and aims at forming a judgement of that which surrounds and circumscribes it, and the

proper place for the consideration of it is the transcendental dialectic. These four propositions, "In mundo non

datur hiatus, non datur saltus, non datur casus, non datur fatum," as well as all principles of transcendental

origin, we could very easily exhibit in their proper order, that is, in conformity with the order of the

categories, and assign to each its proper place. But the already practised reader will do this for himself, or

discover the clue to such an arrangement. But the combined result of all is simply this, to admit into the

empirical synthesis nothing which might cause a break in or be foreign to the understanding and the

continuous connection of all phenomena, that is, the unity of the conceptions of the understanding. For in the

understanding alone is the unity of experience, in which all perceptions must have their assigned place,

Whether the field of possibility be greater than that of reality, and whether the field of the latter be itself

greater than that of necessity, are interesting enough questions, and quite capable of synthetic solution,

questions, however, which come under the jurisdiction of reason alone. For they are tantamount to asking

whether all things as phenomena do without exception belong to the complex and connected whole of a

single experience, of which every given perception is a part which therefore cannot be conjoined with any

other phenomena or, whether my perceptions can belong to more than one possible experience? The

understanding gives to experience, according to the subjective and formal conditions, of sensibility as well as

of apperception, the rules which alone make this experience possible. Other forms of intuition besides those

of space and time, other forms of understanding besides the discursive forms of thought, or of cognition by

means of conceptions, we can neither imagine nor make intelligible to ourselves; and even if we could, they

would still not belong to experience, which is the only mode of cognition by which objects are presented to

us. Whether other perceptions besides those which belong to the total of our possible experience, and

consequently whether some other sphere of matter exists, the understanding has no power to decide, its

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proper occupation being with the synthesis of that which is given. Moreover, the poverty of the usual

arguments which go to prove the existence of a vast sphere of possibility, of which all that is real (every

object of experience) is but a small part, is very remarkable. "All real is possible"; from this follows naturally,

according to the logical laws of conversion, the particular proposition: "Some possible is real." Now this

seems to be equivalent to: "Much is possible that is not real." No doubt it does seem as if we ought to

consider the sum of the possible to be greater than that of the real, from the fact that something must be added

to the former to constitute the latter. But this notion of adding to the possible is absurd. For that which is not

in the sum of the possible, and consequently requires to be added to it, is manifestly impossible. In addition to

accordance with the formal conditions of experience, the understanding requires a connection with some

perception; but that which is connected with this perception is real, even although it is not immediately

perceived. But that another series of phenomena, in complete coherence with that which is given in

perception, consequently more than one allembracing experience is possible, is an inference which cannot

be concluded from the data given us by experience, and still less without any data at all. That which is

possible only under conditions which are themselves merely possible, is not possible in any respect. And yet

we can find no more certain ground on which to base the discussion of the question whether the sphere of

I have merely mentioned these questions, that in treating of the conception of the understanding, there might

be no omission of anything that, in the common opinion, belongs to them. In reality, however, the notion of

absolute possibility (possibility which is valid in every respect) is not a mere conception of the

understanding, which can be employed empirically, but belongs to reason alone, which passes the bounds of

all empirical use of the understanding. We have, therefore, contented ourselves with a merely critical remark,

Before concluding this fourth section, and at the same time the system of all principles of the pure

understanding, it seems proper to mention the reasons which induced me to term the principles of modality

postulates. This expression I do not here use in the sense which some more recent philosophers, contrary to

its meaning with mathematicians, to whom the word properly belongs, attach to it that of a proposition,

namely, immediately certain, requiring neither deduction nor proof. For if, in the case of synthetical

propositions, however evident they may be, we accord to them without deduction, and merely on the strength

of their own pretensions, unqualified belief, all critique of the understanding is entirely lost; and, as there is

no want of bold pretensions, which the common belief (though for the philosopher this is no credential) does

not reject, the understanding lies exposed to every delusion and conceit, without the power of refusing its

assent to those assertions, which, though illegitimate, demand acceptance as veritable axioms. When,

therefore, to the conception of a thing an a priori determination is synthetically added, such a proposition

must obtain, if not a proof, at least a deduction of the legitimacy of its assertion.

The principles of modality are, however, not objectively synthetical, for the predicates of possibility, reality,

and necessity do not in the least augment the conception of that of which they are affirmed, inasmuch as they

contribute nothing to the representation of the object. But as they are, nevertheless, always synthetical, they

are so merely subjectively. That is to say, they have a reflective power, and apply to the conception of a

thing, of which, in other respects, they affirm nothing, the faculty of cognition in which the conception

originates and has its seat. So that if the conception merely agree with the formal conditions of experience, its

object is called possible; if it is in connection with perception, and determined thereby, the object is real; if it

is determined according to conceptions by means of the connection of perceptions, the object is called

necessary. The principles of modality therefore predicate of a conception nothing more than the procedure of

the faculty of cognition which generated it. Now a postulate in mathematics is a practical proposition which

contains nothing but the synthesis by which we present an object to ourselves, and produce the conception of

it, for example "With a given line, to describe a circle upon a plane, from a given point"; and such a

proposition does not admit of proof, because the procedure, which it requires, is exactly that by which alone it

is possible to generate the conception of such a figure. With the same right, accordingly, can we postulate the

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principles of modality, because they do not augment* the conception of a thing but merely indicate the

*When I think the reality of a thing, I do really think more than the possibility, but not in the thing; for that

can never contain more in reality than was contained in its complete possibility. But while the notion of

possibility is merely the notion of a position of thing in relation to the understanding (its empirical use),

It is very remarkable that we cannot perceive the possibility of a thing from the category alone, but must

always have an intuition, by which to make evident the objective reality of the pure conception of the

understanding. Take, for example, the categories of relation. How (1) a thing can exist only as a subject, and

not as a mere determination of other things, that is, can be substance; or how (2), because something exists,

some other thing must exist, consequently how a thing can be a cause; or how (3), when several things exist,

from the fact that one of these things exists, some consequence to the others follows, and reciprocally, and in

this way a community of substances can be possible are questions whose solution cannot be obtained from

mere conceptions. The very same is the case with the other categories; for example, how a thing can be of the

same sort with many others, that is, can be a quantity, and so on. So long as we have not intuition we cannot

know whether we do really think an object by the categories, and where an object can anywhere be found to

cohere with them, and thus the truth is established, that the categories are not in themselves cognitions, but

mere forms of thought for the construction of cognitions from given intuitions. For the same reason is it true

that from categories alone no synthetical proposition can be made. For example: "In every existence there is

substance," that is, something that can exist only as a subject and not as mere predicate; or, "Everything is a

quantity" to construct propositions such as these, we require something to enable us to go out beyond the

given conception and connect another with it. For the same reason the attempt to prove a synthetical

proposition by means of mere conceptions, for example: "Everything that exists contingently has a cause,"

has never succeeded. We could never get further than proving that, without this relation to conceptions, we

could not conceive the existence of the contingent, that is, could not a priori through the understanding

cognize the existence of such a thing; but it does not hence follow that this is also the condition of the

possibility of the thing itself that is said to be contingent. If, accordingly; we look back to our proof of the

principle of causality, we shall find that we were able to prove it as valid only of objects of possible

experience, and, indeed, only as itself the principle of the possibility of experience, Consequently of the

cognition of an object given in empirical intuition, and not from mere conceptions. That, however, the

proposition: "Everything that is contingent must have a cause," is evident to every one merely from

conceptions, is not to be denied. But in this case the conception of the contingent is cogitated as involving not

the category of modality (as that the nonexistence of which can be conceive but that of relation (as that

which can exist only as the consequence of something else), and so it is really an identical proposition: "That

which can exist only as a consequence, has a cause." In fact, when we have to give examples of contingent

existence, we always refer to changes, and not merely to the possibility of conceiving the opposite.* But

change is an event, which, as such, is possible only through a cause, and considered per se its nonexistence

is therefore possible, and we become cognizant of its contingency from the fact that it can exist only as the

effect of a cause. Hence, if a thing is assumed to be contingent, it is an analytical proposition to say, it has a

*We can easily conceive the nonexistence of matter; but the ancients did not thence infer its contingency.

But even the alternation of the existence and nonexistence of a given state in a thing, in which all change

consists, by no means proves the contingency of that state the ground of proof being the reality of its

opposite. For example, a body is in a state of rest after motion, but we cannot infer the contingency of the

motion from the fact that the former is the opposite of the latter. For this opposite is merely a logical and not

a real opposite to the other. If we wish to demonstrate the contingency of the motion, what we ought to prove

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is that, instead of the motion which took place in the preceding point of time, it was possible for the body to

have been then in rest, not, that it is afterwards in rest; for in this case, both opposites are perfectly consistent

But it is still more remarkable that, to understand the possibility of things according to the categories and thus

to demonstrate the objective reality of the latter, we require not merely intuitions, but external intuitions. If,

for example, we take the pure conceptions of relation, we find that (1) for the purpose of presenting to the

conception of substance something permanent in intuition corresponding thereto and thus of demonstrating

the objective reality of this conception, we require an intuition (of matter) in space, because space alone is

permanent and determines things as such, while time, and with it all that is in the internal sense, is in a state

of continual flow; (2) in order to represent change as the intuition corresponding to the conception of

causality, we require the representation of motion as change in space; in fact, it is through it alone that

changes, the possibility of which no pure understanding can perceive, are capable of being intuited. Change is

the connection of determinations contradictorily opposed to each other in the existence of one and the same

thing. Now, how it is possible that out of a given state one quite opposite to it in the same thing should

follow, reason without an example can not only not conceive, but cannot even make intelligible without

intuition; and this intuition is the motion of a point in space; the existence of which in different spaces (as a

consequence of opposite determinations) alone makes the intuition of change possible. For, in order to make

even internal change cognitable, we require to represent time, as the form of the internal sense, figuratively

by a line, and the internal change by the drawing of that line (motion), and consequently are obliged to

employ external intuition to be able to represent the successive existence of ourselves in different states. The

proper ground of this fact is that all change to be perceived as change presupposes something permanent in

intuition, while in the internal sense no permanent intuition is to be found. Lastly, the objective possibility of

the category of community cannot be conceived by mere reason, and consequently its objective reality cannot

be demonstrated without an intuition, and that external in space. For how can we conceive the possibility of

community, that is, when several substances exist, that some effect on the existence of the one follows from

the existence of the other, and reciprocally, and therefore that, because something exists in the latter,

something else must exist in the former, which could not be understood from its own existence alone? For

this is the very essence of community which is inconceivable as a property of things which are perfectly

isolated. Hence, Leibnitz, in attributing to the substances of the world as cogitated by the understanding

alone a community, required the mediating aid of a divinity; for, from their existence, such a property

seemed to him with justice inconceivable. But we can very easily conceive the possibility of community (of

substances as phenomena) if we represent them to ourselves as in space, consequently in external intuition.

For external intuition contains in itself a priori formal external relations, as the conditions of the possibility of

the real relations of action and reaction, and therefore of the possibility of community. With the same ease

can it be demonstrated, that the possibility of things as quantities, and consequently the objective reality of

the category of quantity, can be grounded only in external intuition, and that by its means alone is the notion

of quantity appropriated by the internal sense. But I must avoid prolixity, and leave the task of illustrating this

The above remarks are of the greatest importance, not only for the confirmation of our previous confutation

of idealism, but still more when the subject of selfcognition by mere internal consciousness and the

determination of our own nature without the aid of external empirical intuitions is under discussion, for the

The result of the whole of this part of the analytic of principles is, therefore: "All principles of the pure

understanding are nothing more than a priori principles of the possibility of experience, and to experience

alone do all a priori synthetical propositions apply and relate"; indeed, their possibility itself rests entirely on

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We have now not only traversed the region of the pure understanding and carefully surveyed every part of it,

but we have also measured it, and assigned to everything therein its proper place. But this land is an island,

and enclosed by nature herself within unchangeable limits. It is the land of truth (an attractive word),

surrounded by a wide and stormy ocean, the region of illusion, where many a fogbank, many an iceberg,

seems to the mariner, on his voyage of discovery, a new country, and, while constantly deluding him with

vain hopes, engages him in dangerous adventures, from which he never can desist, and which yet he never

can bring to a termination. But before venturing upon this sea, in order to explore it in its whole extent, and to

arrive at a certainty whether anything is to be discovered there, it will not be without advantage if we cast our

eyes upon the chart of the land that we are about to leave, and to ask ourselves, firstly, whether we cannot rest

perfectly contented with what it contains, or whether we must not of necessity be contented with it, if we can

find nowhere else a solid foundation to build upon; and, secondly, by what title we possess this land itself,

and how we hold it secure against all hostile claims? Although, in the course of our analytic, we have already

given sufficient answers to these questions, yet a summary recapitulation of these solutions may be useful in

strengthening our conviction, by uniting in one point the momenta of the arguments.

We have seen that everything which the understanding draws from itself, without borrowing from experience,

it nevertheless possesses only for the behoof and use of experience. The principles of the pure understanding,

whether constitutive a priori (as the mathematical principles), or merely regulative (as the dynamical),

contain nothing but the pure schema, as it were, of possible experience. For experience possesses its unity

from the synthetical unity which the understanding, originally and from itself, imparts to the synthesis of the

imagination in relation to apperception, and in a priori relation to and agreement with which phenomena, as

data for a possible cognition, must stand. But although these rules of the understanding are not only a priori

true, but the very source of all truth, that is, of the accordance of our cognition with objects, and on this

ground, that they contain the basis of the possibility of experience, as the ensemble of all cognition, it seems

to us not enough to propound what is true we desire also to be told what we want to know. If, then, we learn

nothing more by this critical examination than what we should have practised in the merely empirical use of

the understanding, without any such subtle inquiry, the presumption is that the advantage we reap from it is

not worth the labour bestowed upon it. It may certainly be answered that no rash curiosity is more prejudicial

to the enlargement of our knowledge than that which must know beforehand the utility of this or that piece of

information which we seek, before we have entered on the needful investigations, and before one could form

the least conception of its utility, even though it were placed before our eyes. But there is one advantage in

such transcendental inquiries which can be made comprehensible to the dullest and most reluctant learner

this, namely, that the understanding which is occupied merely with empirical exercise, and does not reflect on

the sources of its own cognition, may exercise its functions very well and very successfully, but is quite

unable to do one thing, and that of very great importance, to determine, namely, the bounds that limit its

employment, and to know what lies within or without its own sphere. This purpose can be obtained only by

such profound investigations as we have instituted. But if it cannot distinguish whether certain questions lie

within its horizon or not, it can never be sure either as to its claims or possessions, but must lay its account

with many humiliating corrections, when it transgresses, as it unavoidably will, the limits of its own territory,

That the understanding, therefore, cannot make of its a priori principles, or even of its conceptions, other than

an empirical use, is a proposition which leads to the most important results. A transcendental use is made of a

conception in a fundamental proposition or principle, when it is referred to things in general and considered

as things in themselves; an empirical use, when it is referred merely to phenomena, that is, to objects of a

possible experience. That the latter use of a conception is the only admissible one is evident from the reasons

following. For every conception are requisite, firstly, the logical form of a conception (of thought) general;

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 103

and, secondly, the possibility of presenting to this an object to which it may apply. Failing this latter, it has no

sense, and utterly void of content, although it may contain the logical function for constructing a conception

from certain data. Now, object cannot be given to a conception otherwise than by intuition, and, even if a

pure intuition antecedent to the object is a priori possible, this pure intuition can itself obtain objective

validity only from empirical intuition, of which it is itself but the form. All conceptions, therefore, and with

them all principles, however high the degree of their a priori possibility, relate to empirical intuitions, that is,

to data towards a possible experience. Without this they possess no objective validity, but are mere play of

imagination or of understanding with images or notions. Let us take, for example, the conceptions of

mathematics, and first in its pure intuitions. "Space has three dimensions" "Between two points there can be

only one straight line," etc. Although all these principles, and the representation of the object with which this

science occupies itself, are generated in the mind entirely a priori, they would nevertheless have no

significance if we were not always able to exhibit their significance in and by means of phenomena

(empirical objects). Hence it is requisite that an abstract conception be made sensuous, that is, that an object

corresponding to it in intuition be forthcoming, otherwise the conception remains, as we say, without sense,

that is, without meaning. Mathematics fulfils this requirement by the construction of the figure, which is a

phenomenon evident to the senses. The same science finds support and significance in number; this in its turn

finds it in the fingers, or in counters, or in lines and points. The conception itself is always produced a priori,

together with the synthetical principles or formulas from such conceptions; but the proper employment of

them, and their application to objects, can exist nowhere but in experience, the possibility of which, as

That this is also the case with all of the categories and the principles based upon them is evident from the fact

that we cannot render intelligible the possibility of an object corresponding to them without having recourse

to the conditions of sensibility, consequently, to the form of phenomena, to which, as their only proper

objects, their use must therefore be confined, inasmuch as, if this condition is removed, all significance, that

is, all relation to an object, disappears, and no example can be found to make it comprehensible what sort of

The conception of quantity cannot be explained except by saying that it is the determination of a thing

whereby it can be cogitated how many times one is placed in it. But this "how many times" is based upon

successive repetition, consequently upon time and the synthesis of the homogeneous therein. Reality, in

contradistinction to negation, can be explained only by cogitating a time which is either filled therewith or is

void. If I leave out the notion of permanence (which is existence in all time), there remains in the conception

of substance nothing but the logical notion of subject, a notion of which I endeavour to realize by

representing to myself something that can exist only as a subject. But not only am I perfectly ignorant of any

conditions under which this logical prerogative can belong to a thing, I can make nothing out of the notion,

and draw no inference from it, because no object to which to apply the conception is determined, and we

consequently do not know whether it has any meaning at all. In like manner, if I leave out the notion of time,

in which something follows upon some other thing in conformity with a rule, I can find nothing in the pure

category, except that there is a something of such a sort that from it a conclusion may be drawn as to the

existence of some other thing. But in this case it would not only be impossible to distinguish between a cause

and an effect, but, as this power to draw conclusions requires conditions of which I am quite ignorant, the

conception is not determined as to the mode in which it ought to apply to an object. The socalled principle:

"Everything that is contingent has a cause," comes with a gravity and selfassumed authority that seems to

require no support from without. But, I ask, what is meant by contingent? The answer is that the

nonexistence of which is possible. But I should like very well to know by what means this possibility of

nonexistence is to be cognized, if we do not represent to ourselves a succession in the series of phenomena,

and in this succession an existence which follows a nonexistence, or conversely, consequently, change. For

to say, that the nonexistence of a thing is not selfcontradictory is a lame appeal to a logical condition,

which is no doubt a necessary condition of the existence of the conception, but is far from being sufficient for

the real objective possibility of nonexistence. I can annihilate in thought every existing substance without

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 104

selfcontradiction, but I cannot infer from this their objective contingency in existence, that is to say, the

possibility of their nonexistence in itself. As regards the category of community, it may easily be inferred

that, as the pure categories of substance and causality are incapable of a definition and explanation sufficient

to determine their object without the aid of intuition, the category of reciprocal causality in the relation of

substances to each other (commercium) is just as little susceptible thereof. Possibility, existence, and

necessity nobody has ever yet been able to explain without being guilty of manifest tautology, when the

definition has been drawn entirely from the pure understanding. For the substitution of the logical possibility

of the conception the condition of which is that it be not selfcontradictory, for the transcendental

possibility of things the condition of which is that there be an object corresponding to the conception, is a

*In one word, to none of these conceptions belongs a corresponding object, and consequently their real

possibility cannot be demonstrated, if we take away sensuous intuition the only intuition which we possess

and there then remains nothing but the logical possibility, that is, the fact that the conception or thought is

possible which, however, is not the question; what we want to know being, whether it relates to an object

It follows incontestably, that the pure conceptions of the understanding are incapable of transcendental, and

must always be of empirical use alone, and that the principles of the pure understanding relate only to the

general conditions of a possible experience, to objects of the senses, and never to things in general, apart from

Transcendental analytic has accordingly this important result, to wit, that the understanding is competent'

effect nothing a priori, except the anticipation of the form of a possible experience in general, and that, as that

which is not phenomenon cannot be an object of experience, it can never overstep the limits of sensibility,

within which alone objects are presented to us. Its principles are merely principles of the exposition of

phenomena, and the proud name of an ontology, which professes to present synthetical cognitions a priori of

things in general in a systematic doctrine, must give place to the modest title of analytic of the pure

Thought is the act of referring a given intuition to an object. If the mode of this intuition is unknown to us,

the object is merely transcendental, and the conception of the understanding is employed only

transcendentally, that is, to produce unity in the thought of a manifold in general. Now a pure category, in

which all conditions of sensuous intuition as the only intuition we possess are abstracted, does not

determine an object, but merely expresses the thought of an object in general, according to different modes.

Now, to employ a conception, the function of judgement is required, by which an object is subsumed under

the conception, consequently the at least formal condition, under which something can be given in intuition.

Failing this condition of judgement (schema), subsumption is impossible; for there is in such a case nothing

given, which may be subsumed under the conception. The merely transcendental use of the categories is

therefore, in fact, no use at all and has no determined, or even, as regards its form, determinable object.

Hence it follows that the pure category is incompetent to establish a synthetical a priori principle, and that the

principles of the pure understanding are only of empirical and never of transcendental use, and that beyond

the sphere of possible experience no synthetical a priori principles are possible.

It may be advisable, therefore, to express ourselves thus. The pure categories, apart from the formal

conditions of sensibility, have a merely transcendental meaning, but are nevertheless not of transcendental

use, because this is in itself impossible, inasmuch as all the conditions of any employment or use of them (in

judgements) are absent, to wit, the formal conditions of the subsumption of an object under these

conceptions. As, therefore, in the character of pure categories, they must be employed empirically, and

cannot be employed transcendentally, they are of no use at all, when separated from sensibility, that is, they

cannot be applied to an object. They are merely the pure form of the employment of the understanding in

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 105

respect of objects in general and of thought, without its being at the same time possible to think or to

But there lurks at the foundation of this subject an illusion which it is very difficult to avoid. The categories

are not based, as regards their origin, upon sensibility, like the forms of intuition, space, and time; they seem,

therefore, to be capable of an application beyond the sphere of sensuous objects. But this is not the case. They

are nothing but mere forms of thought, which contain only the logical faculty of uniting a priori in

consciousness the manifold given in intuition. Apart, then, from the only intuition possible for us, they have

still less meaning than the pure sensuous forms, space and time, for through them an object is at least given,

while a mode of connection of the manifold, when the intuition which alone gives the manifold is wanting,

has no meaning at all. At the same time, when we designate certain objects as phenomena or sensuous

existences, thus distinguishing our mode of intuiting them from their own nature as things in themselves, it is

evident that by this very distinction we as it were place the latter, considered in this their own nature,

although we do not so intuite them, in opposition to the former, or, on the other hand, we do so place other

possible things, which are not objects of our senses, but are cogitated by the understanding alone, and call

them intelligible existences (noumena). Now the question arises whether the pure conceptions of our

understanding do possess significance in respect of these latter, and may possibly be a mode of cognizing

But we are met at the very commencement with an ambiguity, which may easily occasion great

misapprehension. The understanding, when it terms an object in a certain relation phenomenon, at the same

time forms out of this relation a representation or notion of an object in itself, and hence believes that it can

form also conceptions of such objects. Now as the understanding possesses no other fundamental conceptions

besides the categories, it takes for granted that an object considered as a thing in itself must be capable of

being thought by means of these pure conceptions, and is thereby led to hold the perfectly undetermined

conception of an intelligible existence, a something out of the sphere of our sensibility, for a determinate

conception of an existence which we can cognize in some way or other by means of the understanding.

If, by the term noumenon, we understand a thing so far as it is not an object of our sensuous intuition, thus

making abstraction of our mode of intuiting it, this is a noumenon in the negative sense of the word. But if we

understand by it an object of a nonsensuous intuition, we in this case assume a peculiar mode of intuition,

an intellectual intuition, to wit, which does not, however, belong to us, of the very possibility of which we

The doctrine of sensibility is also the doctrine of noumena in the negative sense, that is, of things which the

understanding is obliged to cogitate apart from any relation to our mode of intuition, consequently not as

mere phenomena, but as things in themselves. But the understanding at the same time comprehends that it

cannot employ its categories for the consideration of things in themselves, because these possess significance

only in relation to the unity of intuitions in space and time, and that they are competent to determine this

unity by means of general a priori connecting conceptions only on account of the pure ideality of space and

time. Where this unity of time is not to be met with, as is the case with noumena, the whole use, indeed the

whole meaning of the categories is entirely lost, for even the possibility of things to correspond to the

categories is in this case incomprehensible. On this point, I need only refer the reader to what I have said at

the commencement of the General Remark appended to the foregoing chapter. Now, the possibility of a thing

can never be proved from the fact that the conception of it is not selfcontradictory, but only by means of an

intuition corresponding to the conception. If, therefore, we wish to apply the categories to objects which

cannot be regarded as phenomena, we must have an intuition different from the sensuous, and in this case the

objects would be a noumena in the positive sense of the word. Now, as such an intuition, that is, an

intellectual intuition, is no part of our faculty of cognition, it is absolutely impossible for the categories to

possess any application beyond the limits of experience. It may be true that there are intelligible existences to

which our faculty of sensuous intuition has no relation, and cannot be applied, but our conceptions of the

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 106

understanding, as mere forms of thought for our sensuous intuition, do not extend to these. What, therefore,

If I take away from an empirial intuition all thought (by means of the categories), there remains no cognition

of any object; for by means of mere intuition nothing is cogitated, and, from the existence of such or such an

affection of sensibility in me, it does not follow that this affection or representation has any relation to an

object without me. But if I take away all intuition, there still remains the form of thought, that is, the mode of

determining an object for the manifold of a possible intuition. Thus the categories do in some measure really

extend further than sensuous intuition, inasmuch as they think objects in general, without regard to the mode

(of sensibility) in which these objects are given. But they do not for this reason apply to and determine a

wider sphere of objects, because we cannot assume that such can be given, without presupposing the

possibility of another than the sensuous mode of intuition, a supposition we are not justified in making.

I call a conception problematical which contains in itself no contradiction, and which is connected with other

cognitions as a limitation of given conceptions, but whose objective reality cannot be cognized in any

manner. The conception of a noumenon, that is, of a thing which must be cogitated not as an object of sense,

but as a thing in itself (solely through the pure understanding), is not selfcontradictory, for we are not

entitled to maintain that sensibility is the only possible mode of intuition. Nay, further, this conception is

necessary to restrain sensuous intuition within the bounds of phenomena, and thus to limit the objective

validity of sensuous cognition; for things in themselves, which lie beyond its province, are called noumena

for the very purpose of indicating that this cognition does not extend its application to all that the

understanding thinks. But, after all, the possibility of such noumena is quite incomprehensible, and beyond

the sphere of phenomena, all is for us a mere void; that is to say, we possess an understanding whose

province does problematically extend beyond this sphere, but we do not possess an intuition, indeed, not even

the conception of a possible intuition, by means of which objects beyond the region of sensibility could be

given us, and in reference to which the understanding might be employed assertorically. The conception of a

noumenon is therefore merely a limitative conception and therefore only of negative use. But it is not an

arbitrary or fictitious notion, but is connected with the limitation of sensibility, without, however, being

The division of objects into phenomena and noumena, and of the world into a mundus sensibilis and

intelligibilis is therefore quite inadmissible in a positive sense, although conceptions do certainly admit of

such a division; for the class of noumena have no determinate object corresponding to them, and cannot

therefore possess objective validity. If we abandon the senses, how can it be made conceivable that the

categories (which are the only conceptions that could serve as conceptions for noumena) have any sense or

meaning at all, inasmuch as something more than the mere unity of thought, namely, a possible intuition, is

requisite for their application to an object? The conception of a noumenon, considered as merely

problematical, is, however, not only admissible, but, as a limitative conception of sensibility, absolutely

necessary. But, in this case, a noumenon is not a particular intelligible object for our understanding; on the

contrary, the kind of understanding to which it could belong is itself a problem, for we cannot form the most

distant conception of the possibility of an understanding which should cognize an object, not discursively by

means of categories, but intuitively in a nonsensuous intuition. Our understanding attains in this way a sort

of negative extension. That is to say, it is not limited by, but rather limits, sensibility, by giving the name of

noumena to things, not considered as phenomena, but as things in themselves. But it at the same time

prescribes limits to itself, for it confesses itself unable to cognize these by means of the categories, and hence

I find, however, in the writings of modern authors, an entirely different use of the expressions, mundus

sensibilis and intelligibilis, which quite departs from the meaning of the ancients an acceptation in which,

indeed, there is to be found no difficulty, but which at the same time depends on mere verbal quibbling.

According to this meaning, some have chosen to call the complex of phenomena, in so far as it is intuited,

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 107

mundus sensibilis, but in so far as the connection thereof is cogitated according to general laws of thought,

mundus intelligibilis. Astronomy, in so far as we mean by the word the mere observation of the starry heaven,

may represent the former; a system of astronomy, such as the Copernican or Newtonian, the latter. But such

twisting of words is a mere sophistical subterfuge, to avoid a difficult question, by modifying its meaning to

suit our own convenience. To be sure, understanding and reason are employed in the cognition of

phenomena; but the question is, whether these can be applied when the object is not a phenomenon and in

this sense we regard it if it is cogitated as given to the understanding alone, and not to the senses. The

question therefore is whether, over and above the empirical use of the understanding, a transcendental use is

possible, which applies to the noumenon as an object. This question we have answered in the negative.

When therefore we say, the senses represent objects as they appear, the understanding as they are, the latter

statement must not be understood in a transcendental, but only in an empirical signification, that is, as they

must be represented in the complete connection of phenomena, and not according to what they may be, apart

from their relation to possible experience, consequently not as objects of the pure understanding. For this

must ever remain unknown to us. Nay, it is also quite unknown to us whether any such transcendental or

extraordinary cognition is possible under any circumstances, at least, whether it is possible by means of our

categories. Understanding and sensibility, with us, can determine objects only in conjunction. If we separate

them, we have intuitions without conceptions, or conceptions without intuitions; in both cases,

If, after all our inquiries and explanations, any one still hesitates to abandon the mere transcendental use of

the categories, let him attempt to construct with them a synthetical proposition. It would, of course, be

unnecessary for this purpose to construct an analytical proposition, for that does not extend the sphere of the

understanding, but, being concerned only about what is cogitated in the conception itself, it leaves it quite

undecided whether the conception has any relation to objects, or merely indicates the unity of thought

complete abstraction being made of the modi in which an object may be given: in such a proposition, it is

sufficient for the understanding to know what lies in the conception to what it applies is to it indifferent. The

attempt must therefore be made with a synthetical and socalled transcendental principle, for example:

"Everything that exists, exists as substance," or, "Everything that is contingent exists as an effect of some

other thing, viz., of its cause." Now I ask, whence can the understanding draw these synthetical propositions,

when the conceptions contained therein do not relate to possible experience but to things in themselves

(noumena)? Where is to be found the third term, which is always requisite PURE site in a synthetical

proposition, which may connect in the same proposition conceptions which have no logical (analytical)

connection with each other? The proposition never will be demonstrated, nay, more, the possibility of any

such pure assertion never can be shown, without making reference to the empirical use of the understanding,

and thus, ipso facto, completely renouncing pure and nonsensuous judgement. Thus the conception of pure

and merely intelligible objects is completely void of all principles of its application, because we cannot

imagine any mode in which they might be given, and the problematical thought which leaves a place open for

them serves only, like a void space, to limit the use of empirical principles, without containing at the same

Reflection (reflexio) is not occupied about objects themselves, for the purpose of directly obtaining

conceptions of them, but is that state of the mind in which we set ourselves to discover the subjective

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 108

conditions under which we obtain conceptions. It is the consciousness of the relation of given representations

to the different sources or faculties of cognition, by which alone their relation to each other can be rightly

determined. The first question which occurs in considering our representations is to what faculty of cognition

do they belong? To the understanding or to the senses? Many judgements are admitted to be true from mere

habit or inclination; but, because reflection neither precedes nor follows, it is held to be a judgement that has

its origin in the understanding. All judgements do not require examination, that is, investigation into the

grounds of their truth. For, when they are immediately certain (for example: "Between two points there can

be only one straight line"), no better or less mediate test of their truth can be found than that which they

themselves contain and express. But all judgement, nay, all comparisons require reflection, that is, a

distinction of the faculty of cognition to which the given conceptions belong. The act whereby I compare my

representations with the faculty of cognition which originates them, and whereby I distinguish whether they

are compared with each other as belonging to the pure understanding or to sensuous intuition, I term

transcendental reflection. Now, the relations in which conceptions can stand to each other are those of

identity and difference, agreement and opposition, of the internal and external, finally, of the determinable

and the determining (matter and form). The proper determination of these relations rests on the question, to

what faculty of cognition they subjectively belong, whether to sensibility or understanding? For, on the

manner in which we solve this question depends the manner in which we must cogitate these relations.

Before constructing any objective judgement, we compare the conceptions that are to be placed in the

judgement, and observe whether there exists identity (of many representations in one conception), if a general

judgement is to be constructed, or difference, if a particular; whether there is agreement when affirmative;

and opposition when negative judgements are to be constructed, and so on. For this reason we ought to call

these conceptions, conceptions of comparison (conceptus comparationis). But as, when the question is not as

to the logical form, but as to the content of conceptions, that is to say, whether the things themselves are

identical or different, in agreement or opposition, and so on, the things can have a twofold relation to our

faculty of cognition, to wit, a relation either to sensibility or to the understanding, and as on this relation

depends their relation to each other, transcendental reflection, that is, the relation of given representations to

one or the other faculty of cognition, can alone determine this latter relation. Thus we shall not be able to

discover whether the things are identical or different, in agreement or opposition, etc., from the mere

conception of the things by means of comparison (comparatio), but only by distinguishing the mode of

cognition to which they belong, in other words, by means of transcendental reflection. We may, therefore,

with justice say, that logical reflection is mere comparison, for in it no account is taken of the faculty of

cognition to which the given conceptions belong, and they are consequently, as far as regards their origin, to

be treated as homogeneous; while transcendental reflection (which applies to the objects themselves) contains

the ground of the possibility of objective comparison of representations with each other, and is therefore very

different from the former, because the faculties of cognition to which they belong are not even the same.

Transcendental reflection is a duty which no one can neglect who wishes to establish an a priori judgement

upon things. We shall now proceed to fulfil this duty, and thereby throw not a little light on the question as to

1. Identity and Difference. When an object is presented to us several times, but always with the same internal

determinations (qualitas et quantitas), it, if an object of pure understanding, is always the same, not several

things, but only one thing (numerica identitas); but if a phenomenon, we do not concern ourselves with

comparing the conception of the thing with the conception of some other, but, although they may be in this

respect perfectly the same, the difference of place at the same time is a sufficient ground for asserting the

numerical difference of these objects (of sense). Thus, in the case of two drops of water, we may make

complete abstraction of all internal difference (quality and quantity), and, the fact that they are intuited at the

same time in different places, is sufficient to justify us in holding them to be numerically different. Leibnitz

regarded phenomena as things in themselves, consequently as intelligibilia, that is, objects of pure

understanding (although, on account of the confused nature of their representations, he gave them the name

of phenomena), and in this case his principle of the indiscernible (principium identatis indiscernibilium) is

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 109

not to be impugned. But, as phenomena are objects of sensibility, and, as the understanding, in respect of

them, must be employed empirically and not purely or transcendentally, plurality and numerical difference

are given by space itself as the condition of external phenomena. For one part of space, although it may be

perfectly similar and equal to another part, is still without it, and for this reason alone is different from the

latter, which is added to it in order to make up a greater space. It follows that this must hold good of all things

that are in the different parts of space at the same time, however similar and equal one may be to another.

2. Agreement and Opposition. When reality is represented by the pure understanding (realitas noumenon),

opposition between realities is incogitable such a relation, that is, that when these realities are connected in

one subject, they annihilate the effects of each other and may be represented in the formula 3 3 = 0. On the

other hand, the real in a phenomenon (realitas phaenomenon) may very well be in mutual opposition, and,

when united in the same subject, the one may completely or in part annihilate the effect or consequence of the

other; as in the case of two moving forces in the same straight line drawing or impelling a point in opposite

directions, or in the case of a pleasure counterbalancing a certain amount of pain.

3. The Internal and External. In an object of the pure understanding, only that is internal which has no

relation (as regards its existence) to anything different from itself. On the other hand, the internal

determinations of a substantia phaenomenon in space are nothing but relations, and it is itself nothing more

than a complex of mere relations. Substance in space we are cognizant of only through forces operative in it,

either drawing others towards itself (attraction), or preventing others from forcing into itself (repulsion and

impenetrability). We know no other properties that make up the conception of substance phenomenal in

space, and which we term matter. On the other hand, as an object of the pure understanding, every substance

must have internal determination and forces. But what other internal attributes of such an object can I think

than those which my internal sense presents to me? That, to wit, which in either itself thought, or something

analogous to it. Hence Leibnitz, who looked upon things as noumena, after denying them everything like

external relation, and therefore also composition or combination, declared that all substances, even the

component parts of matter, were simple substances with powers of representation, in one word, monads.

4. Matter and Form. These two conceptions lie at the foundation of all other reflection, so inseparably are

they connected with every mode of exercising the understanding. The former denotes the determinable in

general, the second its determination, both in a transcendental sense, abstraction being made of every

difference in that which is given, and of the mode in which it is determined. Logicians formerly termed the

universal, matter, the specific difference of this or that part of the universal, form. In a judgement one may

call the given conceptions logical matter (for the judgement), the relation of these to each other (by means of

the copula), the form of the judgement. In an object, the composite parts thereof (essentialia) are the matter;

the mode in which they are connected in the object, the form. In respect to things in general, unlimited reality

was regarded as the matter of all possibility, the limitation thereof (negation) as the form, by which one thing

is distinguished from another according to transcendental conceptions. The understanding demands that

something be given (at least in the conception), in order to be able to determine it in a certain manner. Hence,

in a conception of the pure understanding, the matter precedes the form, and for this reason Leibnitz first

assumed the existence of things (monads) and of an internal power of representation in them, in order to

found upon this their external relation and the community their state (that is, of their representations). Hence,

with him, space and time were possible the former through the relation of substances, the latter through the

connection of their determinations with each other, as causes and effects. And so would it really be, if the

pure understanding were capable of an immediate application to objects, and if space and time were

determinations of things in themselves. But being merely sensuous intuitions, in which we determine all

objects solely as phenomena, the form of intuition (as a subjective property of sensibility) must antecede all

matter (sensations), consequently space and time must antecede all phenomena and all data of experience,

and rather make experience itself possible. But the intellectual philosopher could not endure that the form

should precede the things themselves and determine their possibility; an objection perfectly correct, if we

assume that we intuite things as they are, although with confused representation. But as sensuous intuition is

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 110

a peculiar subjective condition, which is a priori at the foundation of all perception, and the form of which is

primitive, the form must be given per se, and so far from matter (or the things themselves which appear) lying

at the foundation of experience (as we must conclude, if we judge by mere conceptions), the very possibility

of itself presupposes, on the contrary, a given formal intuition (space and time).

Let me be allowed to term the position which we assign to a conception either in the sensibility or in the pure

understanding, the transcendental place. In this manner, the appointment of the position which must be taken

by each conception according to the difference in its use, and the directions for determining this place to all

conceptions according to rules, would be a transcendental topic, a doctrine which would thoroughly shield us

from the surreptitious devices of the pure understanding and the delusions which thence arise, as it would

always distinguish to what faculty of cognition each conception properly belonged. Every conception, every

title, under which many cognitions rank together, may be called a logical place. Upon this is based the logical

topic of Aristotle, of which teachers and rhetoricians could avail themselves, in order, under certain titles of

thought, to observe what would best suit the matter they had to treat, and thus enable themselves to quibble

Transcendental topic, on the contrary, contains nothing more than the abovementioned four titles of all

comparison and distinction, which differ from categories in this respect, that they do not represent the object

according to that which constitutes its conception (quantity, reality), but set forth merely the comparison of

representations, which precedes our conceptions of things. But this comparison requires a previous reflection,

that is, a determination of the place to which the representations of the things which are compared belong,

whether, to wit, they are cogitated by the pure understanding, or given by sensibility.

Conceptions may be logically compared without the trouble of inquiring to what faculty their objects belong,

whether as noumena, to the understanding, or as phenomena, to sensibility. If, however, we wish to employ

these conceptions in respect of objects, previous transcendental reflection is necessary. Without this reflection

I should make a very unsafe use of these conceptions, and construct pretended synthetical propositions which

critical reason cannot acknowledge and which are based solely upon a transcendental amphiboly, that is, upon

For want of this doctrine of transcendental topic, and consequently deceived by the amphiboly of the

conceptions of reflection, the celebrated Leibnitz constructed an intellectual system of the world, or rather,

believed himself competent to cognize the internal nature of things, by comparing all objects merely with the

understanding and the abstract formal conceptions of thought. Our table of the conceptions of reflection gives

us the unexpected advantage of being able to exhibit the distinctive peculiarities of his system in all its parts,

and at the same time of exposing the fundamental principle of this peculiar mode of thought, which rested

upon naught but a misconception. He compared all things with each other merely by means of conceptions,

and naturally found no other differences than those by which the understanding distinguishes its pure

conceptions one from another. The conditions of sensuous intuition, which contain in themselves their own

means of distinction, he did not look upon as primitive, because sensibility was to him but a confused mode

of representation and not any particular source of representations. A phenomenon was for him the

representation of the thing in itself, although distinguished from cognition by the understanding only in

respect of the logical form the former with its usual want of analysis containing, according to him, a certain

mixture of collateral representations in its conception of a thing, which it is the duty of the understanding to

separate and distinguish. In one word, Leibnitz intellectualized phenomena, just as Locke, in his system of

noogony (if I may be allowed to make use of such expressions), sensualized the conceptions of the

understanding, that is to say, declared them to be nothing more than empirical or abstract conceptions of

reflection. Instead of seeking in the understanding and sensibility two different sources of representations,

which, however, can present us with objective judgements of things only in conjunction, each of these great

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 111

men recognized but one of these faculties, which, in their opinion, applied immediately to things in

themselves, the other having no duty but that of confusing or arranging the representations of the former.

Accordingly, the objects of sense were compared by Leibnitz as things in general merely in the

1st. He compares them in regard to their identity or difference as judged by the understanding. As,

therefore, he considered merely the conceptions of objects, and not their position in intuition, in which alone

objects can be given, and left quite out of sight the transcendental locale of these conceptions whether, that

is, their object ought to be classed among phenomena, or among things in themselves, it was to be expected

that he should extend the application of the principle of indiscernibles, which is valid solely of conceptions of

things in general, to objects of sense (mundus phaenomenon), and that he should believe that he had thereby

contributed in no small degree to extend our knowledge of nature. In truth, if I cognize in all its inner

determinations a drop of water as a thing in itself, I cannot look upon one drop as different from another, if

the conception of the one is completely identical with that of the other. But if it is a phenomenon in space, it

has a place not merely in the understanding (among conceptions), but also in sensuous external intuition (in

space), and in this case, the physical locale is a matter of indifference in regard to the internal determinations

of things, and one place, B, may contain a thing which is perfectly similar and equal to another in a place, A,

just as well as if the two things were in every respect different from each other. Difference of place without

any other conditions, makes the plurality and distinction of objects as phenomena, not only possible in itself,

but even necessary. Consequently, the above socalled law is not a law of nature. It is merely an analytical

2nd. The principle: "Realities (as simple affirmations) never logically contradict each other," is a proposition

perfectly true respecting the relation of conceptions, but, whether as regards nature, or things in themselves

(of which we have not the slightest conception), is without any the least meaning. For real opposition, in

which A B is = 0, exists everywhere, an opposition, that is, in which one reality united with another in the

same subject annihilates the effects of the other a fact which is constantly brought before our eyes by the

different antagonistic actions and operations in nature, which, nevertheless, as depending on real forces, must

be called realitates phaenomena. General mechanics can even present us with the empirical condition of this

opposition in an a priori rule, as it directs its attention to the opposition in the direction of forces a condition

of which the transcendental conception of reality can tell us nothing. Although M. Leibnitz did not announce

this proposition with precisely the pomp of a new principle, he yet employed it for the establishment of new

propositions, and his followers introduced it into their LeibnitzioWolfian system of philosophy. According

to this principle, for example, all evils are but consequences of the limited nature of created beings, that is,

negations, because these are the only opposite of reality. (In the mere conception of a thing in general this is

really the case, but not in things as phenomena.) In like manner, the upholders of this system deem it not only

possible, but natural also, to connect and unite all reality in one being, because they acknowledge no other

sort of opposition than that of contradiction (by which the conception itself of a thing is annihilated), and find

themselves unable to conceive an opposition of reciprocal destruction, so to speak, in which one real cause

destroys the effect of another, and the conditions of whose representation we meet with only in sensibility.

3rd. The Leibnitzian monadology has really no better foundation than on this philosopher's mode of falsely

representing the difference of the internal and external solely in relation to the understanding. Substances, in

general, must have something inward, which is therefore free from external relations, consequently from that

of composition also. The simple that which can be represented by a unit is therefore the foundation of that

which is internal in things in themselves. The internal state of substances cannot therefore consist in place,

shape, contact, or motion, determinations which are all external relations, and we can ascribe to them no other

than that whereby we internally determine our faculty of sense itself, that is to say, the state of representation.

Thus, then, were constructed the monads, which were to form the elements of the universe, the active force of

which consists in representation, the effects of this force being thus entirely confined to themselves.

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 112

For the same reason, his view of the possible community of substances could not represent it but as a

predetermined harmony, and by no means as a physical influence. For inasmuch as everything is occupied

only internally, that is, with its own representations, the state of the representations of one substance could

not stand in active and living connection with that of another, but some third cause operating on all without

exception was necessary to make the different states correspond with one another. And this did not happen by

means of assistance applied in each particular case (systema assistentiae), but through the unity of the idea of

a cause occupied and connected with all substances, in which they necessarily receive, according to the

Leibnitzian school, their existence and permanence, consequently also reciprocal correspondence, according

4th. This philosopher's celebrated doctrine of space and time, in which he intellectualized these forms of

sensibility, originated in the same delusion of transcendental reflection. If I attempt to represent by the mere

understanding, the external relations of things, I can do so only by employing the conception of their

reciprocal action, and if I wish to connect one state of the same thing with another state, I must avail myself

of the notion of the order of cause and effect. And thus Leibnitz regarded space as a certain order in the

community of substances, and time as the dynamical sequence of their states. That which space and time

possess proper to themselves and independent of things, he ascribed to a necessary confusion in our

conceptions of them, whereby that which is a mere form of dynamical relations is held to be a selfexistent

intuition, antecedent even to things themselves. Thus space and time were the intelligible form of the

connection of things (substances and their states) in themselves. But things were intelligible substances

(substantiae noumena). At the same time, he made these conceptions valid of phenomena, because he did not

allow to sensibility a peculiar mode of intuition, but sought all, even the empirical representation of objects,

in the understanding, and left to sense naught but the despicable task of confusing and disarranging the

But even if we could frame any synthetical proposition concerning things in themselves by means of the pure

understanding (which is impossible), it could not apply to phenomena, which do not represent things in

themselves. In such a case I should be obliged in transcendental reflection to compare my conceptions only

under the conditions of sensibility, and so space and time would not be determinations of things in

themselves, but of phenomena. What things may be in themselves, I know not and need not know, because a

I must adopt the same mode of procedure with the other conceptions of reflection. Matter is substantia

phaenomenon. That in it which is internal I seek to discover in all parts of space which it occupies, and in all

the functions and operations it performs, and which are indeed never anything but phenomena of the external

sense. I cannot therefore find anything that is absolutely, but only what is comparatively internal, and which

itself consists of external relations. The absolutely internal in matter, and as it should be according to the pure

understanding, is a mere chimera, for matter is not an object for the pure understanding. But the

transcendental object, which is the foundation of the phenomenon which we call matter, is a mere nescio

quid, the nature of which we could not understand, even though someone were found able to tell us. For we

can understand nothing that does not bring with it something in intuition corresponding to the expressions

employed. If, by the complaint of being unable to perceive the internal nature of things, it is meant that we do

not comprehend by the pure understanding what the things which appear to us may be in themselves, it is a

silly and unreasonable complaint; for those who talk thus really desire that we should be able to cognize,

consequently to intuite, things without senses, and therefore wish that we possessed a faculty of cognition

perfectly different from the human faculty, not merely in degree, but even as regards intuition and the mode

thereof, so that thus we should not be men, but belong to a class of beings, the possibility of whose existence,

much less their nature and constitution, we have no means of cognizing. By observation and analysis of

phenomena we penetrate into the interior of nature, and no one can say what progress this knowledge may

make in time. But those transcendental questions which pass beyond the limits of nature, we could never

answer, even although all nature were laid open to us, because we have not the power of observing our own

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 113

mind with any other intuition than that of our internal sense. For herein lies the mystery of the origin and

source of our faculty of sensibility. Its application to an object, and the transcendental ground of this unity of

subjective and objective, lie too deeply concealed for us, who cognize ourselves only through the internal

sense, consequently as phenomena, to be able to discover in our existence anything but phenomena, the

nonsensuous cause of which we at the same time earnestly desire to penetrate to.

The great utility of this critique of conclusions arrived at by the processes of mere reflection consists in its

clear demonstration of the nullity of all conclusions respecting objects which are compared with each other in

the understanding alone, while it at the same time confirms what we particularly insisted on, namely, that,

although phenomena are not included as things in themselves among the objects of the pure understanding,

they are nevertheless the only things by which our cognition can possess objective reality, that is to say,

When we reflect in a purely logical manner, we do nothing more than compare conceptions in our

understanding, to discover whether both have the same content, whether they are selfcontradictory or not,

whether anything is contained in either conception, which of the two is given, and which is merely a mode of

thinking that given. But if I apply these conceptions to an object in general (in the transcendental sense),

without first determining whether it is an object of sensuous or intellectual intuition, certain limitations

present themselves, which forbid us to pass beyond the conceptions and render all empirical use of them

impossible. And thus these limitations prove that the representation of an object as a thing in general is not

only insufficient, but, without sensuous determination and independently of empirical conditions,

selfcontradictory; that we must therefore make abstraction of all objects, as in logic, or, admitting them,

must think them under conditions of sensuous intuition; that, consequently, the intelligible requires an

altogether peculiar intuition, which we do not possess, and in the absence of which it is for us nothing; while,

on the other hand phenomena cannot be objects in themselves. For, when I merely think things in general, the

difference in their external relations cannot constitute a difference in the things themselves; on the contrary,

the former presupposes the latter, and if the conception of one of two things is not internally different from

that of the other, I am merely thinking the same thing in different relations. Further, by the addition of one

affirmation (reality) to the other, the positive therein is really augmented, and nothing is abstracted or

withdrawn from it; hence the real in things cannot be in contradiction with or opposition to itself and so on.

The true use of the conceptions of reflection in the employment of the understanding has, as we have shown,

been so misconceived by Leibnitz, one of the most acute philosophers of either ancient or modern times, that

he has been misled into the construction of a baseless system of intellectual cognition, which professes to

determine its objects without the intervention of the senses. For this reason, the exposition of the cause of the

amphiboly of these conceptions, as the origin of these false principles, is of great utility in determining with

It is right to say whatever is affirmed or denied of the whole of a conception can be affirmed or denied of any

part of it (dictum de omni et nullo); but it would be absurd so to alter this logical proposition as to say

whatever is not contained in a general conception is likewise not contained in the particular conceptions

which rank under it; for the latter are particular conceptions, for the very reason that their content is greater

than that which is cogitated in the general conception. And yet the whole intellectual system of Leibnitz is

based upon this false principle, and with it must necessarily fall to the ground, together with all the

ambiguous principles in reference to the employment of the understanding which have thence originated.

Leibnitz's principle of the identity of indiscernibles or indistinguishables is really based on the presupposition

that, if in the conception of a thing a certain distinction is not to be found, it is also not to be met with in

things themselves; that, consequently, all things are completely identical (numero eadem) which are not

distinguishable from each other (as to quality or quantity) in our conceptions of them. But, as in the mere

conception of anything abstraction has been made of many necessary conditions of intuition, that of which

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 114

abstraction has been made is rashly held to be nonexistent, and nothing is attributed to the thing but what is

The conception of a cubic foot of space, however I may think it, is in itself completely identical. But two

cubic feet in space are nevertheless distinct from each other from the sole fact of their being in different

places (they are numero diversa); and these places are conditions of intuition, wherein the object of this

conception is given, and which do not belong to the conception, but to the faculty of sensibility. In like

manner, there is in the conception of a thing no contradiction when a negative is not connected with an

affirmative; and merely affirmative conceptions cannot, in conjunction, produce any negation. But in

sensuous intuition, wherein reality (take for example, motion) is given, we find conditions (opposite

directions) of which abstraction has been made in the conception of motion in general which render

possible a contradiction or opposition (not indeed of a logical kind) and which from pure positives produce

zero = 0. We are therefore not justified in saying that all reality is in perfect agreement and harmony, because

no contradiction is discoverable among its conceptions.* According to mere conceptions, that which is

internal is the substratum of all relations or external determinations. When, therefore, I abstract all conditions

of intuition, and confine myself solely to the conception of a thing in general, I can make abstraction of all

external relations, and there must nevertheless remain a conception of that which indicates no relation, but

merely internal determinations. Now it seems to follow that in everything (substance) there is something

which is absolutely internal and which antecedes all external determinations, inasmuch as it renders them

possible; and that therefore this substratum is something which does not contain any external relations and is

consequently simple (for corporeal things are never anything but relations, at least of their parts external to

each other); and, inasmuch as we know of no other absolutely internal determinations than those of the

internal sense, this substratum is not only simple, but also, analogously with our internal sense, determined

through representations, that is to say, all things are properly monads, or simple beings endowed with the

power of representation. Now all this would be perfectly correct, if the conception of a thing were the only

necessary condition of the presentation of objects of external intuition. It is, on the contrary, manifest that a

permanent phenomenon in space (impenetrable extension) can contain mere relations, and nothing that is

absolutely internal, and yet be the primary substratum of all external perception. By mere conceptions I

cannot think anything external, without, at the same time, thinking something internal, for the reason that

conceptions of relations presuppose given things, and without these are impossible. But, as an intuition there

is something (that is, space, which, with all it contains, consists of purely formal, or, indeed, real relations)

which is not found in the mere conception of a thing in general, and this presents to us the substratum which

could not be cognized through conceptions alone, I cannot say: because a thing cannot be represented by

mere conceptions without something absolutely internal, there is also, in the things themselves which are

contained under these conceptions, and in their intuition nothing external to which something absolutely

internal does not serve as the foundation. For, when we have made abstraction of all the conditions of

intuition, there certainly remains in the mere conception nothing but the internal in general, through which

alone the external is possible. But this necessity, which is grounded upon abstraction alone, does not obtain in

the case of things themselves, in so far as they are given in intuition with such determinations as express mere

relations, without having anything internal as their foundation; for they are not things of a thing of which we

can neither for they are not things in themselves, but only phenomena. What we cognize in matter is nothing

but relations (what we call its internal determinations are but comparatively internal). But there are some

selfsubsistent and permanent, through which a determined object is given. That I, when abstraction is made

of these relations, have nothing more to think, does not destroy the conception of a thing as phenomenon, nor

the conception of an object in abstracto, but it does away with the possibility of an object that is determinable

according to mere conceptions, that is, of a noumenon. It is certainly startling to hear that a thing consists

solely of relations; but this thing is simply a phenomenon, and cannot be cogitated by means of the mere

categories: it does itself consist in the mere relation of something in general to the senses. In the same way,

we cannot cogitate relations of things in abstracto, if we commence with conceptions alone, in any other

manner than that one is the cause of determinations in the other; for that is itself the conception of the

understanding or category of relation. But, as in this case we make abstraction of all intuition, we lose

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 115

altogether the mode in which the manifold determines to each of its parts its place, that is, the form of

*If any one wishes here to have recourse to the usual subterfuge, and to say, that at least realitates noumena

cannot be in opposition to each other, it will be requisite for him to adduce an example of this pure and

nonsensuous reality, that it may be understood whether the notion represents something or nothing. But an

example cannot be found except in experience, which never presents to us anything more than phenomena;

and thus the proposition means nothing more than that the conception which contains only affirmatives does

If by intelligible objects we understand things which can be thought by means of the pure categories, without

the need of the schemata of sensibility, such objects are impossible. For the condition of the objective use of

all our conceptions of understanding is the mode of our sensuous intuition, whereby objects are given; and, if

we make abstraction of the latter, the former can have no relation to an object. And even if we should

suppose a different kind of intuition from our own, still our functions of thought would have no use or

signification in respect thereof. But if we understand by the term, objects of a nonsensuous intuition, in

respect of which our categories are not valid, and of which we can accordingly have no knowledge (neither

intuition nor conception), in this merely negative sense noumena must be admitted. For this is no more than

saying that our mode of intuition is not applicable to all things, but only to objects of our senses, that

consequently its objective validity is limited, and that room is therefore left for another kind of intuition, and

thus also for things that may be objects of it. But in this sense the conception of a noumenon is problematical,

that is to say, it is the notion of that it that it is possible, nor that it is impossible, inasmuch as we do not know

of any mode of intuition besides the sensuous, or of any other sort of conceptions than the categories a mode

of intuition and a kind of conception neither of which is applicable to a nonsensuous object. We are on this

account incompetent to extend the sphere of our objects of thought beyond the conditions of our sensibility,

and to assume the existence of objects of pure thought, that is, of noumena, inasmuch as these have no true

positive signification. For it must be confessed of the categories that they are not of themselves sufficient for

the cognition of things in themselves and, without the data of sensibility, are mere subjective forms of the

unity of the understanding. Thought is certainly not a product of the senses, and in so far is not limited by

them, but it does not therefore follow that it may be employed purely and without the intervention of

sensibility, for it would then be without reference to an object. And we cannot call a noumenon an object of

pure thought; for the representation thereof is but the problematical conception of an object for a perfectly

different intuition and a perfectly different understanding from ours, both of which are consequently

themselves problematical. The conception of a noumenon is therefore not the conception of an object, but

merely a problematical conception inseparably connected with the limitation of our sensibility. That is to say,

this conception contains the answer to the question: "Are there objects quite unconnected with, and

independent of, our intuition?" a question to which only an indeterminate answer can be given. That answer

is: "Inasmuch as sensuous intuition does not apply to all things without distinction, there remains room for

other and different objects." The existence of these problematical objects is therefore not absolutely denied,

in the absence of a determinate conception of them, but, as no category is valid in respect of them, neither

Understanding accordingly limits sensibility, without at the same time enlarging its own field. While,

moreover, it forbids sensibility to apply its forms and modes to things in themselves and restricts it to the

sphere of phenomena, it cogitates an object in itself, only, however, as a transcendental object, which is the

cause of a phenomenon (consequently not itself a phenomenon), and which cannot be thought either as a

quantity or as reality, or as substance (because these conceptions always require sensuous forms in which to

determine an object) an object, therefore, of which we are quite unable to say whether it can be met with in

ourselves or out of us, whether it would be annihilated together with sensibility, or, if this were taken away,

would continue to exist. If we wish to call this object a noumenon, because the representation of it is

nonsensuous, we are at liberty to do so. But as we can apply to it none of the conceptions of our

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 116

understanding, the representation is for us quite void, and is available only for the indication of the limits of

our sensuous intuition, thereby leaving at the same time an empty space, which we are competent to fill by

The critique of the pure understanding, accordingly, does not permit us to create for ourselves a new field of

objects beyond those which are presented to us as phenomena, and to stray into intelligible worlds; nay, it

does not even allow us to endeavour to form so much as a conception of them. The specious error which

leads to this and which is a perfectly excusable one lies in the fact that the employment of the

understanding, contrary to its proper purpose and destination, is made transcendental, and objects, that is,

possible intuitions, are made to regulate themselves according to conceptions, instead of the conceptions

arranging themselves according to the intuitions, on which alone their own objective validity rests. Now the

reason of this again is that apperception, and with it thought, antecedes all possible determinate arrangement

of representations. Accordingly we think something in general and determine it on the one hand sensuously,

but, on the other, distinguish the general and in abstracto represented object from this particular mode of

intuiting it. In this case there remains a mode of determining the object by mere thought, which is really but a

logical form without content, which, however, seems to us to be a mode of the existence of the object in itself

Before ending this transcendental analytic, we must make an addition, which, although in itself of no

particular importance, seems to be necessary to the completeness of the system. The highest conception, with

which a transcendental philosophy commonly begins, is the division into possible and impossible. But as all

division presupposes a divided conception, a still higher one must exist, and this is the conception of an

object in general problematically understood and without its being decided whether it is something or

nothing. As the categories are the only conceptions which apply to objects in general, the distinguishing of an

object, whether it is something or nothing, must proceed according to the order and direction of the

1. To the categories of quantity, that is, the conceptions of all, many, and one, the conception which

annihilates all, that is, the conception of none, is opposed. And thus the object of a conception, to which no

intuition can be found to correspond, is = nothing. That is, it is a conception without an object (ens rationis),

like noumena, which cannot be considered possible in the sphere of reality, though they must not therefore be

held to be impossible or like certain new fundamental forces in matter, the existence of which is cogitable

without contradiction, though, as examples from experience are not forthcoming, they must not be regarded

2. Reality is something; negation is nothing, that is, a conception of the absence of an object, as cold, a

3. The mere form of intuition, without substance, is in itself no object, but the merely formal condition of an

object (as phenomenon), as pure space and pure time. These are certainly something, as forms of intuition,

4. The object of a conception which is selfcontradictory, is nothing, because the conception is nothing is

The table of this division of the conception of nothing (the corresponding division of the conception of

something does not require special description) must therefore be arranged as follows:

CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena. 117

We see that the ens rationis is distinguished from the nihil negativum or pure nothing by the consideration

that the former must not be reckoned among possibilities, because it is a mere fiction though not

selfcontradictory, while the latter is completely opposed to all possibility, inasmuch as the conception

annihilates itself. Both, however, are empty conceptions. On the other hand, the nihil privativum and ens

imaginarium are empty data for conceptions. If light be not given to the senses, we cannot represent to

ourselves darkness, and if extended objects are not perceived, we cannot represent space. Neither the

negation, nor the mere form of intuition can, without something real, be an object.

We termed dialectic in general a logic of appearance. This does not signify a doctrine of probability; for

probability is truth, only cognized upon insufficient grounds, and though the information it gives us is

imperfect, it is not therefore deceitful. Hence it must not be separated from the analytical part of logic. Still

less must phenomenon and appearance be held to be identical. For truth or illusory appearance does not

reside in the object, in so far as it is intuited, but in the judgement upon the object, in so far as it is thought. It

is, therefore, quite correct to say that the senses do not err, not because they always judge correctly, but

because they do not judge at all. Hence truth and error, consequently also, illusory appearance as the cause of

error, are only to be found in a judgement, that is, in the relation of an object to our understanding. In a

cognition which completely harmonizes with the laws of the understanding, no error can exist. In a

representation of the senses as not containing any judgement there is also no error. But no power of nature

can of itself deviate from its own laws. Hence neither the understanding per se (without the influence of

another cause), nor the senses per se, would fall into error; the former could not, because, if it acts only

according to its own laws, the effect (the judgement) must necessarily accord with these laws. But in

accordance with the laws of the understanding consists the formal element in all truth. In the senses there is

no judgement neither a true nor a false one. But, as we have no source of cognition besides these two, it

follows that error is caused solely by the unobserved influence of the sensibility upon the understanding. And

thus it happens that the subjective grounds of a judgement and are confounded with the objective, and cause

them to deviate from their proper determination,* just as a body in motion would always of itself proceed in a

straight line, but if another impetus gives to it a different direction, it will then start off into a curvilinear line

of motion. To distinguish the peculiar action of the understanding from the power which mingles with it, it is

necessary to consider an erroneous judgement as the diagonal between two forces, that determine the

judgement in two different directions, which, as it were, form an angle, and to resolve this composite

operation into the simple ones of the understanding and the sensibility. In pure a priori judgements this must

be done by means of transcendental reflection, whereby, as has been already shown, each representation has

its place appointed in the corresponding faculty of cognition, and consequently the influence of the one

*Sensibility, subjected to the understanding, as the object upon which the understanding employs its

functions, is the source of real cognitions. But, in so far as it exercises an influence upon the action of the

understanding and determines it to judgement, sensibility is itself the cause of error.

It is not at present our business to treat of empirical illusory appearance (for example, optical illusion), which

occurs in the empirical application of otherwise correct rules of the understanding, and in which the

judgement is misled by the influence of imagination. Our purpose is to speak of transcendental illusory

appearance, which influences principles that are not even applied to experience, for in this case we should

possess a sure test of their correctness but which leads us, in disregard of all the warnings of criticism,

completely beyond the empirical employment of the categories and deludes us with the chimera of an

extension of the sphere of the pure understanding. We shall term those principles the application of which is

confined entirely within the limits of possible experience, immanent; those, on the other hand, which

transgress these limits, we shall call transcendent principles. But by these latter I do not understand principles

of the transcendental use or misuse of the categories, which is in reality a mere fault of the judgement when

not under due restraint from criticism, and therefore not paying sufficient attention to the limits of the sphere

in which the pure understanding is allowed to exercise its functions; but real principles which exhort us to

break down all those barriers, and to lay claim to a perfectly new field of cognition, which recognizes no line

of demarcation. Thus transcendental and transcendent are not identical terms. The principles of the pure

understanding, which we have already propounded, ought to be of empirical and not of transcendental use,

that is, they are not applicable to any object beyond the sphere of experience. A principle which removes

these limits, nay, which authorizes us to overstep them, is called transcendent. If our criticism can succeed in

exposing the illusion in these pretended principles, those which are limited in their employment to the sphere

of experience may be called, in opposition to the others, immanent principles of the pure understanding.

Logical illusion, which consists merely in the imitation of the form of reason (the illusion in sophistical

syllogisms), arises entirely from a want of due attention to logical rules. So soon as the attention is awakened

to the case before us, this illusion totally disappears. Transcendental illusion, on the contrary, does not cease

to exist, even after it has been exposed, and its nothingness clearly perceived by means of transcendental

criticism. Take, for example, the illusion in the proposition: "The world must have a beginning in time." The

cause of this is as follows. In our reason, subjectively considered as a faculty of human cognition, there exist

fundamental rules and maxims of its exercise, which have completely the appearance of objective principles.

Now from this cause it happens that the subjective necessity of a certain connection of our conceptions, is

regarded as an objective necessity of the determination of things in themselves. This illusion it is impossible

to avoid, just as we cannot avoid perceiving that the sea appears to be higher at a distance than it is near the

shore, because we see the former by means of higher rays than the latter, or, which is a still stronger case, as

even the astronomer cannot prevent himself from seeing the moon larger at its rising than some time

Transcendental dialectic will therefore content itself with exposing the illusory appearance in transcendental

judgements, and guarding us against it; but to make it, as in the case of logical illusion, entirely disappear and

cease to be illusion is utterly beyond its power. For we have here to do with a natural and unavoidable

illusion, which rests upon subjective principles and imposes these upon us as objective, while logical

dialectic, in the detection of sophisms, has to do merely with an error in the logical consequence of the

propositions, or with an artificially constructed illusion, in imitation of the natural error. There is, therefore, a

natural and unavoidable dialectic of pure reason not that in which the bungler, from want of the requisite

knowledge, involves himself, nor that which the sophist devises for the purpose of misleading, but that which

is an inseparable adjunct of human reason, and which, even after its illusions have been exposed, does not

cease to deceive, and continually to lead reason into momentary errors, which it becomes necessary

All our knowledge begins with sense, proceeds thence to understanding, and ends with reason, beyond which

nothing higher can be discovered in the human mind for elaborating the matter of intuition and subjecting it

to the highest unity of thought. At this stage of our inquiry it is my duty to give an explanation of this, the

highest faculty of cognition, and I confess I find myself here in some difficulty. Of reason, as of the

understanding, there is a merely formal, that is, logical use, in which it makes abstraction of all content of

cognition; but there is also a real use, inasmuch as it contains in itself the source of certain conceptions and

principles, which it does not borrow either from the senses or the understanding. The former faculty has been

long defined by logicians as the faculty of mediate conclusion in contradistinction to immediate conclusions

(consequentiae immediatae); but the nature of the latter, which itself generates conceptions, is not to be

understood from this definition. Now as a division of reason into a logical and a transcendental faculty

presents itself here, it becomes necessary to seek for a higher conception of this source of cognition which

shall comprehend both conceptions. In this we may expect, according to the analogy of the conceptions of the

understanding, that the logical conception will give us the key to the transcendental, and that the table of the

functions of the former will present us with the clue to the conceptions of reason.

In the former part of our transcendental logic, we defined the understanding to be the faculty of rules; reason

The term principle is ambiguous, and commonly signifies merely a cognition that may be employed as a

principle, although it is not in itself, and as regards its proper origin, entitled to the distinction. Every general

proposition, even if derived from experience by the process of induction, may serve as the major in a

syllogism; but it is not for that reason a principle. Mathematical axioms (for example, there can be only one

straight line between two points) are general a priori cognitions, and are therefore rightly denominated

principles, relatively to the cases which can be subsumed under them. But I cannot for this reason say that I

cognize this property of a straight line from principles I cognize it only in pure intuition.

Cognition from principles, then, is that cognition in which I cognize the particular in the general by means of

conceptions. Thus every syllogism is a form of the deduction of a cognition from a principle. For the major

always gives a conception, through which everything that is subsumed under the condition thereof is

cognized according to a principle. Now as every general cognition may serve as the major in a syllogism, and

the understanding presents us with such general a priori propositions, they may be termed principles, in

But if we consider these principles of the pure understanding in relation to their origin, we shall find them to

be anything rather than cognitions from conceptions. For they would not even be possible a priori, if we

could not rely on the assistance of pure intuition (in mathematics), or on that of the conditions of a possible

experience. That everything that happens has a cause, cannot be concluded from the general conception of

that which happens; on the contrary the principle of causality instructs us as to the mode of obtaining from

Synthetical cognitions from conceptions the understanding cannot supply, and they alone are entitled to be

called principles. At the same time, all general propositions may be termed comparative principles.

It has been a longcherished wish that (who knows how late), may one day, be happily accomplished that

the principles of the endless variety of civil laws should be investigated and exposed; for in this way alone

can we find the secret of simplifying legislation. But in this case, laws are nothing more than limitations of

our freedom upon conditions under which it subsists in perfect harmony with itself; they consequently have

for their object that which is completely our own work, and of which we ourselves may be the cause by

means of these conceptions. But how objects as things in themselves how the nature of things is

subordinated to principles and is to be determined. according to conceptions, is a question which it seems

well nigh impossible to answer. Be this, however, as it may for on this point our investigation is yet to be

made it is at least manifest from what we have said that cognition from principles is something very

different from cognition by means of the understanding, which may indeed precede other cognitions in the

form of a principle, but in itself in so far as it is synthetical is neither based upon mere thought, nor

The understanding may be a faculty for the production of unity of phenomena by virtue of rules; the reason is

a faculty for the production of unity of rules (of the understanding) under principles. Reason, therefore, never

applies directly to experience, or to any sensuous object; its object is, on the contrary, the understanding, to

the manifold cognition of which it gives a unity a priori by means of conceptions a unity which may be

called rational unity, and which is of a nature very different from that of the unity produced by the

The above is the general conception of the faculty of reason, in so far as it has been possible to make it

A distinction is commonly made between that which is immediately cognized and that which is inferred or

concluded. That in a figure which is bounded by three straight lines there are three angles, is an immediate

cognition; but that these angles are together equal to two right angles, is an inference or conclusion. Now, as

we are constantly employing this mode of thought and have thus become quite accustomed to it, we no longer

remark the above distinction, and, as in the case of the socalled deceptions of sense, consider as

immediately perceived, what has really been inferred. In every reasoning or syllogism, there is a fundamental

proposition, afterwards a second drawn from it, and finally the conclusion, which connects the truth in the

first with the truth in the second and that infallibly. If the judgement concluded is so contained in the first

proposition that it can be deduced from it without the meditation of a third notion, the conclusion is called

immediate (consequentia immediata); I prefer the term conclusion of the understanding. But if, in addition to

the fundamental cognition, a second judgement is necessary for the production of the conclusion, it is called a

conclusion of the reason. In the proposition: All men are mortal, are contained the propositions: Some men

are mortal, Nothing that is not mortal is a man, and these are therefore immediate conclusions from the first.

On the other hand, the proposition: all the learned are mortal, is not contained in the main proposition (for the

conception of a learned man does not occur in it), and it can be deduced from the main proposition only by

In every syllogism I first cogitate a rule (the major) by means of the understanding. In the next place I

subsume a cognition under the condition of the rule (and this is the minor) by means of the judgement. And

finally I determine my cognition by means of the predicate of the rule (this is the conclusio), consequently, I

determine it a priori by means of the reason. The relations, therefore, which the major proposition, as the rule,

represents between a cognition and its condition, constitute the different kinds of syllogisms. These are just

threefold analogously with all judgements, in so far as they differ in the mode of expressing the relation of a

cognition in the understanding namely, categorical, hypothetical, and disjunctive.

When as often happens, the conclusion is a judgement which may follow from other given judgements,

through which a perfectly different object is cogitated, I endeavour to discover in the understanding whether

the assertion in this conclusion does not stand under certain conditions according to a general rule. If I find

such a condition, and if the object mentioned in the conclusion can be subsumed under the given condition,

then this conclusion follows from a rule which is also valid for other objects of cognition. From this we see

that reason endeavours to subject the great variety of the cognitions of the understanding to the smallest

possible number of principles (general conditions), and thus to produce in it the highest unity.

Can we isolate reason, and, if so, is it in this case a peculiar source of conceptions and judgements which

spring from it alone, and through which it can be applied to objects; or is it merely a subordinate faculty,

whose duty it is to give a certain form to given cognitions a form which is called logical, and through which

the cognitions of the understanding are subordinated to each other, and lower rules to higher (those, to wit,

whose condition comprises in its sphere the condition of the others), in so far as this can be done by

comparison? This is the question which we have at present to answer. Manifold variety of rules and unity of

principles is a requirement of reason, for the purpose of bringing the understanding into complete accordance

with itself, just as understanding subjects the manifold content of intuition to conceptions, and thereby

introduces connection into it. But this principle prescribes no law to objects, and does not contain any ground

of the possibility of cognizing or of determining them as such, but is merely a subjective law for the proper

arrangement of the content of the understanding. The purpose of this law is, by a comparison of the

conceptions of the understanding, to reduce them to the smallest possible number, although, at the same time,

it does not justify us in demanding from objects themselves such a uniformity as might contribute to the

convenience and the enlargement of the sphere of the understanding, or in expecting that it will itself thus

receive from them objective validity. In one word, the question is: "does reason in itself, that is, does pure

reason contain a priori synthetical principles and rules, and what are those principles?"

The formal and logical procedure of reason in syllogisms gives us sufficient information in regard to the

ground on which the transcendental principle of reason in its pure synthetical cognition will rest.

1. Reason, as observed in the syllogistic process, is not applicable to intuitions, for the purpose of subjecting

them to rules for this is the province of the understanding with its categories but to conceptions and

judgements. If pure reason does apply to objects and the intuition of them, it does so not immediately, but

mediately through the understanding and its judgements, which have a direct relation to the senses and their

intuition, for the purpose of determining their objects. The unity of reason is therefore not the unity of a

possible experience, but is essentially different from this unity, which is that of the understanding. That

everything which happens has a cause, is not a principle cognized and prescribed by reason. This principle

makes the unity of experience possible and borrows nothing from reason, which, without a reference to

possible experience, could never have produced by means of mere conceptions any such synthetical unity.

2. Reason, in its logical use, endeavours to discover the general condition of its judgement (the conclusion),

and a syllogism is itself nothing but a judgement by means of the subsumption of its condition under a

general rule (the major). Now as this rule may itself be subjected to the same process of reason, and thus the

condition of the condition be sought (by means of a prosyllogism) as long as the process can be continued, it

is very manifest that the peculiar principle of reason in its logical use is to find for the conditioned cognition

of the understanding the unconditioned whereby the unity of the former is completed.

But this logical maxim cannot be a principle of pure reason, unless we admit that, if the conditioned is given,

the whole series of conditions subordinated to one another a series which is consequently itself

unconditioned is also given, that is, contained in the object and its connection.

But this principle of pure reason is evidently synthetical; for, analytically, the conditioned certainly relates to

some condition, but not to the unconditioned. From this principle also there must originate different

synthetical propositions, of which the pure understanding is perfectly ignorant, for it has to do only with

objects of a possible experience, the cognition and synthesis of which is always conditioned. The

unconditioned, if it does really exist, must be especially considered in regard to the determinations which

distinguish it from whatever is conditioned, and will thus afford us material for many a priori synthetical

The principles resulting from this highest principle of pure reason will, however, be transcendent in relation

to phenomena, that is to say, it will be impossible to make any adequate empirical use of this principle. It is

therefore completely different from all principles of the understanding, the use made of which is entirely

immanent, their object and purpose being merely the possibility of experience. Now our duty in the

transcendental dialectic is as follows. To discover whether the principle that the series of conditions (in the

synthesis of phenomena, or of thought in general) extends to the unconditioned is objectively true, or not;

what consequences result therefrom affecting the empirical use of the understanding, or rather whether there

exists any such objectively valid proposition of reason, and whether it is not, on the contrary, a merely logical

precept which directs us to ascend perpetually to still higher conditions, to approach completeness in the

series of them, and thus to introduce into our cognition the highest possible unity of reason. We must

ascertain, I say, whether this requirement of reason has not been regarded, by a misunderstanding, as a

transcendental principle of pure reason, which postulates a thorough completeness in the series of conditions

in objects themselves. We must show, moreover, the misconceptions and illusions that intrude into

syllogisms, the major proposition of which pure reason has supplied a proposition which has perhaps more

of the character of a petitio than of a postulatum and that proceed from experience upwards to its conditions.

The solution of these problems is our task in transcendental dialectic, which we are about to expose even at

its source, that lies deep in human reason. We shall divide it into two parts, the first of which will treat of the

transcendent conceptions of pure reason, the second of transcendent and dialectical syllogisms.

The conceptions of pure reason we do not here speak of the possibility of them are not obtained by

reflection, but by inference or conclusion. The conceptions of understanding are also cogitated a priori

antecedently to experience, and render it possible; but they contain nothing but the unity of reflection upon

phenomena, in so far as these must necessarily belong to a possible empirical consciousness. Through them

alone are cognition and the determination of an object possible. It is from them, accordingly, that we receive

material for reasoning, and antecedently to them we possess no a priori conceptions of objects from which

they might be deduced, On the other hand, the sole basis of their objective reality consists in the necessity

imposed on them, as containing the intellectual form of all experience, of restricting their application and

But the term, conception of reason, or rational conception, itself indicates that it does not confine itself within

the limits of experience, because its objectmatter is a cognition, of which every empirical cognition is but a

part nay, the whole of possible experience may be itself but a part of it a cognition to which no actual

experience ever fully attains, although it does always pertain to it. The aim of rational conceptions is the

comprehension, as that of the conceptions of understanding is the understanding of perceptions. If they

contain the unconditioned, they relate to that to which all experience is subordinate, but which is never itself

an object of experience that towards which reason tends in all its conclusions from experience, and by the

standard of which it estimates the degree of their empirical use, but which is never itself an element in an

empirical synthesis. If, notwithstanding, such conceptions possess objective validity, they may be called

conceptus ratiocinati (conceptions legitimately concluded); in cases where they do not, they have been

admitted on account of having the appearance of being correctly concluded, and may be called conceptus

ratiocinantes (sophistical conceptions). But as this can only be sufficiently demonstrated in that part of our

treatise which relates to the dialectical conclusions of reason, we shall omit any consideration of it in this

place. As we called the pure conceptions of the understanding categories, we shall also distinguish those of

pure reason by a new name and call them transcendental ideas. These terms, however, we must in the first

Despite the great wealth of words which European languages possess, the thinker finds himself often at a loss

for an expression exactly suited to his conception, for want of which he is unable to make himself intelligible

either to others or to himself. To coin new words is a pretension to legislation in language which is seldom

successful; and, before recourse is taken to so desperate an expedient, it is advisable to examine the dead and

learned languages, with the hope and the probability that we may there meet with some adequate expression

of the notion we have in our minds. In this case, even if the original meaning of the word has become

somewhat uncertain, from carelessness or want of caution on the part of the authors of it, it is always better to

adhere to and confirm its proper meaning even although it may be doubtful whether it was formerly used in

exactly this sense than to make our labour vain by want of sufficient care to render ourselves intelligible.

For this reason, when it happens that there exists only a single word to express a certain conception, and this

word, in its usual acceptation, is thoroughly adequate to the conception, the accurate distinction of which

from related conceptions is of great importance, we ought not to employ the expression improvidently, or, for

the sake of variety and elegance of style, use it as a synonym for other cognate words. It is our duty, on the

contrary, carefully to preserve its peculiar signification, as otherwise it easily happens that when the attention

of the reader is no longer particularly attracted to the expression, and it is lost amid the multitude of other

words of very different import, the thought which it conveyed, and which it alone conveyed, is lost with it.

Plato employed the expression idea in a way that plainly showed he meant by it something which is never

derived from the senses, but which far transcends even the conceptions of the understanding (with which

Aristotle occupied himself), inasmuch as in experience nothing perfectly corresponding to them could be

found. Ideas are, according to him, archetypes of things themselves, and not merely keys to possible

experiences, like the categories. In his view they flow from the highest reason, by which they have been

imparted to human reason, which, however, exists no longer in its original state, but is obliged with great

labour to recall by reminiscence which is called philosophy the old but now sadly obscured ideas. I will

not here enter upon any literary investigation of the sense which this sublime philosopher attached to this

expression. I shall content myself with remarking that it is nothing unusual, in common conversation as well

as in written works, by comparing the thoughts which an author has delivered upon a subject, to understand

him better than he understood himself inasmuch as he may not have sufficiently determined his conception,

and thus have sometimes spoken, nay even thought, in opposition to his own opinions.

Plato perceived very clearly that our faculty of cognition has the feeling of a much higher vocation than that

of merely spelling out phenomena according to synthetical unity, for the purpose of being able to read them

as experience, and that our reason naturally raises itself to cognitions far too elevated to admit of the

possibility of an object given by experience corresponding to them cognitions which are nevertheless real,

This philosopher found his ideas especially in all that is practical,* that is, which rests upon freedom, which

in its turn ranks under cognitions that are the peculiar product of reason. He who would derive from

experience the conceptions of virtue, who would make (as many have really done) that, which at best can but

serve as an imperfectly illustrative example, a model for or the formation of a perfectly adequate idea on the

subject, would in fact transform virtue into a nonentity changeable according to time and circumstance and

utterly incapable of being employed as a rule. On the contrary, every one is conscious that, when any one is

held up to him as a model of virtue, he compares this socalled model with the true original which he

possesses in his own mind and values him according to this standard. But this standard is the idea of virtue, in

relation to which all possible objects of experience are indeed serviceable as examples proofs of the

practicability in a certain degree of that which the conception of virtue demands but certainly not as

archetypes. That the actions of man will never be in perfect accordance with all the requirements of the pure

ideas of reason, does not prove the thought to be chimerical. For only through this idea are all judgements as

to moral merit or demerit possible; it consequently lies at the foundation of every approach to moral

perfection, however far removed from it the obstacles in human nature indeterminable as to degree may

*He certainly extended the application of his conception to speculative cognitions also, provided they were

given pure and completely a priori, nay, even to mathematics, although this science cannot possess an object

otherwhere than in Possible experience. I cannot follow him in this, and as little can I follow him in his

mystical deduction of these ideas, or in his hypostatization of them; although, in truth, the elevated and

exaggerated language which he employed in describing them is quite capable of an interpretation more

The Platonic Republic has become proverbial as an example and a striking one of imaginary perfection,

such as can exist only in the brain of the idle thinker; and Brucker ridicules the philosopher for maintaining

that a prince can never govern well, unless he is participant in the ideas. But we should do better to follow up

this thought and, where this admirable thinker leaves us without assistance, employ new efforts to place it in

clearer light, rather than carelessly fling it aside as useless, under the very miserable and pernicious pretext of

impracticability. A constitution of the greatest possible human freedom according to laws, by which the

liberty of every individual can consist with the liberty of every other (not of the greatest possible happiness,

for this follows necessarily from the former), is, to say the least, a necessary idea, which must be placed at the

foundation not only of the first plan of the constitution of a state, but of all its laws. And, in this, it not

necessary at the outset to take account of the obstacles which lie in our way obstacles which perhaps do not

necessarily arise from the character of human nature, but rather from the previous neglect of true ideas in

legislation. For there is nothing more pernicious and more unworthy of a philosopher, than the vulgar appeal

to a socalled adverse experience, which indeed would not have existed, if those institutions had been

established at the proper time and in accordance with ideas; while, instead of this, conceptions, crude for the

very reason that they have been drawn from experience, have marred and frustrated all our better views and

intentions. The more legislation and government are in harmony with this idea, the more rare do punishments

become and thus it is quite reasonable to maintain, as Plato did, that in a perfect state no punishments at all

would be necessary. Now although a perfect state may never exist, the idea is not on that account the less just,

which holds up this maximum as the archetype or standard of a constitution, in order to bring legislative

government always nearer and nearer to the greatest possible perfection. For at what precise degree human

nature must stop in its progress, and how wide must be the chasm which must necessarily exist between the

idea and its realization, are problems which no one can or ought to determine and for this reason, that it is

the destination of freedom to overstep all assigned limits between itself and the idea.

But not only in that wherein human reason is a real causal agent and where ideas are operative causes (of

actions and their objects), that is to say, in the region of ethics, but also in regard to nature herself, Plato saw

clear proofs of an origin from ideas. A plant, and animal, the regular order of nature probably also the

disposition of the whole universe give manifest evidence that they are possible only by means of and

according to ideas; that, indeed, no one creature, under the individual conditions of its existence, perfectly

harmonizes with the idea of the most perfect of its kind just as little as man with the idea of humanity,

which nevertheless he bears in his soul as the archetypal standard of his actions; that, notwithstanding, these

ideas are in the highest sense individually, unchangeably, and completely determined, and are the original

causes of things; and that the totality of connected objects in the universe is alone fully adequate to that idea.

Setting aside the exaggerations of expression in the writings of this philosopher, the mental power exhibited

in this ascent from the ectypal mode of regarding the physical world to the architectonic connection thereof

according to ends, that is, ideas, is an effort which deserves imitation and claims respect. But as regards the

principles of ethics, of legislation, and of religion, spheres in which ideas alone render experience possible,

although they never attain to full expression therein, he has vindicated for himself a position of peculiar

merit, which is not appreciated only because it is judged by the very empirical rules, the validity of which as

principles is destroyed by ideas. For as regards nature, experience presents us with rules and is the source of

truth, but in relation to ethical laws experience is the parent of illusion, and it is in the highest degree

reprehensible to limit or to deduce the laws which dictate what I ought to do, from what is done.

We must, however, omit the consideration of these important subjects, the development of which is in reality

the peculiar duty and dignity of philosophy, and confine ourselves for the present to the more humble but not

less useful task of preparing a firm foundation for those majestic edifices of moral science. For this

foundation has been hitherto insecure from the many subterranean passages which reason in its confident but

vain search for treasures has made in all directions. Our present duty is to make ourselves perfectly

acquainted with the transcendental use made of pure reason, its principles and ideas, that we may be able

properly to determine and value its influence and real worth. But before bringing these introductory remarks

to a close, I beg those who really have philosophy at heart and their number is but small if they shall find

themselves convinced by the considerations following as well as by those above, to exert themselves to

preserve to the expression idea its original signification, and to take care that it be not lost among those other

expressions by which all sorts of representations are loosely designated that the interests of science may not

thereby suffer. We are in no want of words to denominate adequately every mode of representation, without

the necessity of encroaching upon terms which are proper to others. The following is a graduated list of them.

The genus is representation in general (representation. Under it stands representation with consciousness

(perceptio). A perception which relates solely to the subject as a modification of its state, is a sensation

(sensatio), an objective perception is a cognition (cognitio). A cognition is either an intuition or a conception

(intuitus vel conceptus). The former has an immediate relation to the object and is singular and individual; the

latter has but a mediate relation, by means of a characteristic mark which may be common to several things.

A conception is either empirical or pure. A pure conception, in so far as it has its origin in the understanding

alone, and is not the conception of a pure sensuous image, is called notio. A conception formed from notions,

which transcends the possibility of experience, is an idea, or a conception of reason. To one who has

accustomed himself to these distinctions, it must be quite intolerable to hear the representation of the colour

red called an idea. It ought not even to be called a notion or conception of understanding.

Transcendental analytic showed us how the mere logical form of our cognition can contain the origin of pure

conceptions a priori, conceptions which represent objects antecedently to all experience, or rather, indicate

the synthetical unity which alone renders possible an empirical cognition of objects. The form of

judgements converted into a conception of the synthesis of intuitions produced the categories which direct

the employment of the understanding in experience. This consideration warrants us to expect that the form of

syllogisms, when applied to synthetical unity of intuitions, following the rule of the categories, will contain

the origin of particular a priori conceptions, which we may call pure conceptions of reason or transcendental

ideas, and which will determine the use of the understanding in the totality of experience according to

The function of reason in arguments consists in the universality of a cognition according to conceptions, and

the syllogism itself is a judgement which is determined a priori in the whole extent of its condition. The

proposition: "Caius is mortal," is one which may be obtained from experience by the aid of the understanding

alone; but my wish is to find a conception which contains the condition under which the predicate of this

judgement is given in this case, the conception of man and after subsuming under this condition, taken in

its whole extent (all men are mortal), I determine according to it the cognition of the object thought, and say:

Hence, in the conclusion of a syllogism we restrict a predicate to a certain object, after having thought it in

the major in its whole extent under a certain condition. This complete quantity of the extent in relation to

such a condition is called universality (universalitas). To this corresponds totality (universitas) of conditions

in the synthesis of intuitions. The transcendental conception of reason is therefore nothing else than the

conception of the totality of the conditions of a given conditioned. Now as the unconditioned alone renders

possible totality of conditions, and, conversely, the totality of conditions is itself always unconditioned; a

pure rational conception in general can be defined and explained by means of the conception of the

unconditioned, in so far as it contains a basis for the synthesis of the conditioned.

To the number of modes of relation which the understanding cogitates by means of the categories, the

number of pure rational conceptions will correspond. We must therefore seek for, first, an unconditioned of

the categorical synthesis in a subject; secondly, of the hypothetical synthesis of the members of a series;

There are exactly the same number of modes of syllogisms, each of which proceeds through prosyllogisms to

the unconditioned one to the subject which cannot be employed as predicate, another to the presupposition

which supposes nothing higher than itself, and the third to an aggregate of the members of the complete

division of a conception. Hence the pure rational conceptions of totality in the synthesis of conditions have a

necessary foundation in the nature of human reason at least as modes of elevating the unity of the

understanding to the unconditioned. They may have no valid application, corresponding to their

transcendental employment, in concreto, and be thus of no greater utility than to direct the understanding

how, while extending them as widely as possible, to maintain its exercise and application in perfect

But, while speaking here of the totality of conditions and of the unconditioned as the common title of all

conceptions of reason, we again light upon an expression which we find it impossible to dispense with, and

which nevertheless, owing to the ambiguity attaching to it from long abuse, we cannot employ with safety.

The word absolute is one of the few words which, in its original signification, was perfectly adequate to the

conception it was intended to convey a conception which no other word in the same language exactly suits,

and the loss or, which is the same thing, the incautious and loose employment of which must be followed

by the loss of the conception itself. And, as it is a conception which occupies much of the attention of reason,

its loss would be greatly to the detriment of all transcendental philosophy. The word absolute is at present

frequently used to denote that something can be predicated of a thing considered in itself and intrinsically. In

this sense absolutely possible would signify that which is possible in itself (interne) which is, in fact, the

least that one can predicate of an object. On the other hand, it is sometimes employed to indicate that a thing

is valid in all respects for example, absolute sovereignty. Absolutely possible would in this sense signify

that which is possible in all relations and in every respect; and this is the most that can be predicated of the

possibility of a thing. Now these significations do in truth frequently coincide. Thus, for example, that which

is intrinsically impossible, is also impossible in all relations, that is, absolutely impossible. But in most cases

they differ from each other toto caelo, and I can by no means conclude that, because a thing is in itself

possible, it is also possible in all relations, and therefore absolutely. Nay, more, I shall in the sequel show that

absolute necessity does not by any means depend on internal necessity, and that, therefore, it must not be

considered as synonymous with it. Of an opposite which is intrinsically impossible, we may affirm that it is

in all respects impossible, and that, consequently, the thing itself, of which this is the opposite, is absolutely

necessary; but I cannot reason conversely and say, the opposite of that which is absolutely necessary is

intrinsically impossible, that is, that the absolute necessity of things is an internal necessity. For this internal

necessity is in certain cases a mere empty word with which the least conception cannot be connected, while

the conception of the necessity of a thing in all relations possesses very peculiar determinations. Now as the

loss of a conception of great utility in speculative science cannot be a matter of indifference to the

philosopher, I trust that the proper determination and careful preservation of the expression on which the

In this enlarged signification, then, shall I employ the word absolute, in opposition to that which is valid only

in some particular respect; for the latter is restricted by conditions, the former is valid without any restriction

Now the transcendental conception of reason has for its object nothing else than absolute totality in the

synthesis of conditions and does not rest satisfied till it has attained to the absolutely, that is, in all respects

and relations, unconditioned. For pure reason leaves to the understanding everything that immediately relates

to the object of intuition or rather to their synthesis in imagination. The former restricts itself to the absolute

totality in the employment of the conceptions of the understanding and aims at carrying out the synthetical

unity which is cogitated in the category, even to the unconditioned. This unity may hence be called the

rational unity of phenomena, as the other, which the category expresses, may be termed the unity of the

understanding. Reason, therefore, has an immediate relation to the use of the understanding, not indeed in so

far as the latter contains the ground of possible experience (for the conception of the absolute totality of

conditions is not a conception that can be employed in experience, because no experience is unconditioned),

but solely for the purpose of directing it to a certain unity, of which the understanding has no conception, and

the aim of which is to collect into an absolute whole all acts of the understanding. Hence the objective

employment of the pure conceptions of reason is always transcendent, while that of the pure conceptions of

the understanding must, according to their nature, be always immanent, inasmuch as they are limited to

I understand by idea a necessary conception of reason, to which no corresponding object can be discovered in

the world of sense. Accordingly, the pure conceptions of reason at present under consideration are

transcendental ideas. They are conceptions of pure reason, for they regard all empirical cognition as

determined by means of an absolute totality of conditions. They are not mere fictions, but natural and

necessary products of reason, and have hence a necessary relation to the whole sphere of the exercise of the

understanding. And, finally, they are transcendent, and overstep the limits of all experiences, in which,

consequently, no object can ever be presented that would be perfectly adequate to a transcendental idea.

When we use the word idea, we say, as regards its object (an object of the pure understanding), a great deal,

but as regards its subject (that is, in respect of its reality under conditions of experience), exceedingly little,

because the idea, as the conception of a maximum, can never be completely and adequately presented in

concreto. Now, as in the merely speculative employment of reason the latter is properly the sole aim, and as

in this case the approximation to a conception, which is never attained in practice, is the same thing as if the

conception were nonexistent it is commonly said of the conception of this kind, "it is only an idea." So we

might very well say, "the absolute totality of all phenomena is only an idea," for, as we never can present an

adequate representation of it, it remains for us a problem incapable of solution. On the other hand, as in the

practical use of the understanding we have only to do with action and practice according to rules, an idea of

pure reason can always be given really in concreto, although only partially, nay, it is the indispensable

condition of all practical employment of reason. The practice or execution of the idea is always limited and

defective, but nevertheless within indeterminable boundaries, consequently always under the influence of the

conception of an absolute perfection. And thus the practical idea is always in the highest degree fruitful, and

in relation to real actions indispensably necessary. In the idea, pure reason possesses even causality and the

power of producing that which its conception contains. Hence we cannot say of wisdom, in a disparaging

way, "it is only an idea." For, for the very reason that it is the idea of the necessary unity of all possible aims,

it must be for all practical exertions and endeavours the primitive condition and rule a rule which, if not

Now, although we must say of the transcendental conceptions of reason, "they are only ideas," we must not,

on this account, look upon them as superfluous and nugatory. For, although no object can be determined by

them, they can be of great utility, unobserved and at the basis of the edifice of the understanding, as the canon

for its extended and selfconsistent exercise a canon which, indeed, does not enable it to cognize more in an

object than it would cognize by the help of its own conceptions, but which guides it more securely in its

cognition. Not to mention that they perhaps render possible a transition from our conceptions of nature and

the nonego to the practical conceptions, and thus produce for even ethical ideas keeping, so to speak, and

connection with the speculative cognitions of reason. The explication of all this must be looked for in the

But setting aside, in conformity with our original purpose, the consideration of the practical ideas, we proceed

to contemplate reason in its speculative use alone, nay, in a still more restricted sphere, to wit, in the

transcendental use; and here must strike into the same path which we followed in our deduction of the

categories. That is to say, we shall consider the logical form of the cognition of reason, that we may see

whether reason may not be thereby a source of conceptions which enables us to regard objects in themselves

as determined synthetically a priori, in relation to one or other of the functions of reason.

Reason, considered as the faculty of a certain logical form of cognition, is the faculty of conclusion, that is, of

mediate judgement by means of the subsumption of the condition of a possible judgement under the

condition of a given judgement. The given judgement is the general rule (major). The subsumption of the

condition of another possible judgement under the condition of the rule is the minor. The actual judgement,

which enounces the assertion of the rule in the subsumed case, is the conclusion (conclusio). The rule

predicates something generally under a certain condition. The condition of the rule is satisfied in some

particular case. It follows that what was valid in general under that condition must also be considered as valid

in the particular case which satisfies this condition. It is very plain that reason attains to a cognition, by

means of acts of the understanding which constitute a series of conditions. When I arrive at the proposition,

"All bodies are changeable," by beginning with the more remote cognition (in which the conception of body

does not appear, but which nevertheless contains the condition of that conception), "All compound is

changeable," by proceeding from this to a less remote cognition, which stands under the condition of the

former, "Bodies are compound," and hence to a third, which at length connects for me the remote cognition

(changeable) with the one before me, "Consequently, bodies are changeable" I have arrived at a cognition

(conclusion) through a series of conditions (premisses). Now every series, whose exponent (of the categorical

or hypothetical judgement) is given, can be continued; consequently the same procedure of reason conducts

us to the ratiocinatio polysyllogistica, which is a series of syllogisms, that can be continued either on the side

of the conditions (per prosyllogismos) or of the conditioned (per episyllogismos) to an indefinite extent.

But we very soon perceive that the chain or series of prosyllogisms, that is, of deduced cognitions on the side

of the grounds or conditions of a given cognition, in other words, the ascending series of syllogisms must

have a very different relation to the faculty of reason from that of the descending series, that is, the

progressive procedure of reason on the side of the conditioned by means of episyllogisms. For, as in the

former case the cognition (conclusio) is given only as conditioned, reason can attain to this cognition only

under the presupposition that all the members of the series on the side of the conditions are given (totality in

the series of premisses), because only under this supposition is the judgement we may be considering

possible a priori; while on the side of the conditioned or the inferences, only an incomplete and becoming,

and not a presupposed or given series, consequently only a potential progression, is cogitated. Hence, when a

cognition is contemplated as conditioned, reason is compelled to consider the series of conditions in an

ascending line as completed and given in their totality. But if the very same condition is considered at the

same time as the condition of other cognitions, which together constitute a series of inferences or

consequences in a descending line, reason may preserve a perfect indifference, as to how far this progression

may extend a parte posteriori, and whether the totality of this series is possible, because it stands in no need

of such a series for the purpose of arriving at the conclusion before it, inasmuch as this conclusion is

sufficiently guaranteed and determined on grounds a parte priori. It may be the case, that upon the side of the

conditions the series of premisses has a first or highest condition, or it may not possess this, and so be a parte

priori unlimited; but it must, nevertheless, contain totality of conditions, even admitting that we never could

succeed in completely apprehending it; and the whole series must be unconditionally true, if the conditioned,

which is considered as an inference resulting from it, is to be held as true. This is a requirement of reason,

which announces its cognition as determined a priori and as necessary, either in itself and in this case it

needs no grounds to rest upon or, if it is deduced, as a member of a series of grounds, which is itself

We are not at present engaged with a logical dialectic, which makes complete abstraction of the content of

cognition and aims only at unveiling the illusory appearance in the form of syllogisms. Our subject is

transcendental dialectic, which must contain, completely a priori, the origin of certain cognitions drawn from

pure reason, and the origin of certain deduced conceptions, the object of which cannot be given empirically

and which therefore lie beyond the sphere of the faculty of understanding. We have observed, from the

natural relation which the transcendental use of our cognition, in syllogisms as well as in judgements, must

have to the logical, that there are three kinds of dialectical arguments, corresponding to the three modes of

conclusion, by which reason attains to cognitions on principles; and that in all it is the business of reason to

ascend from the conditioned synthesis, beyond which the understanding never proceeds, to the unconditioned

Now the most general relations which can exist in our representations are: 1st, the relation to the subject; 2nd,

the relation to objects, either as phenomena, or as objects of thought in general. If we connect this subdivision

with the main division, all the relations of our representations, of which we can form either a conception or an

idea, are threefold: 1. The relation to the subject; 2. The relation to the manifold of the object as a

Now all pure conceptions have to do in general with the synthetical unity of representations; conceptions of

pure reason (transcendental ideas), on the other hand, with the unconditional synthetical unity of all

conditions. It follows that all transcendental ideas arrange themselves in three classes, the first of which

contains the absolute (unconditioned) unity of the thinking subject, the second the absolute unity of the series

of the conditions of a phenomenon, the third the absolute unity of the condition of all objects of thought in

The thinking subject is the objectmatter of Psychology; the sum total of all phenomena (the world) is the

objectmatter of Cosmology; and the thing which contains the highest condition of the possibility of all that

is cogitable (the being of all beings) is the objectmatter of all Theology. Thus pure reason presents us with

the idea of a transcendental doctrine of the soul (psychologia rationalis), of a transcendental science of the

world (cosmologia rationalis), and finally of a transcendental doctrine of God (theologia transcendentalis).

Understanding cannot originate even the outline of any of these sciences, even when connected with the

highest logical use of reason, that is, all cogitable syllogisms for the purpose of proceeding from one object

(phenomenon) to all others, even to the utmost limits of the empirical synthesis. They are, on the contrary,

What modi of the pure conceptions of reason these transcendental ideas are will be fully exposed in the

following chapter. They follow the guiding thread of the categories. For pure reason never relates

immediately to objects, but to the conceptions of these contained in the understanding. In like manner, it will

be made manifest in the detailed explanation of these ideas how reason, merely through the synthetical use

of the same function which it employs in a categorical syllogism, necessarily attains to the conception of the

absolute unity of the thinking subject how the logical procedure in hypothetical ideas necessarily produces

the idea of the absolutely unconditioned in a series of given conditions, and finally how the mere form of

the disjunctive syllogism involves the highest conception of a being of all beings: a thought which at first

An objective deduction, such as we were able to present in the case of the categories, is impossible as regards

these transcendental ideas. For they have, in truth, no relation to any object, in experience, for the very reason

that they are only ideas. But a subjective deduction of them from the nature of our reason is possible, and has

It is easy to perceive that the sole aim of pure reason is the absolute totality of the synthesis on the side of the

conditions, and that it does not concern itself with the absolute completeness on the Part of the conditioned.

For of the former alone does she stand in need, in order to preposit the whole series of conditions, and thus

present them to the understanding a priori. But if we once have a completely (and unconditionally) given

condition, there is no further necessity, in proceeding with the series, for a conception of reason; for the

understanding takes of itself every step downward, from the condition to the conditioned. Thus the

transcendental ideas are available only for ascending in the series of conditions, till we reach the

unconditioned, that is, principles. As regards descending to the conditioned, on the other hand, we find that

there is a widely extensive logical use which reason makes of the laws of the understanding, but that a

transcendental use thereof is impossible; and that when we form an idea of the absolute totality of such a

synthesis, for example, of the whole series of all future changes in the world, this idea is a mere ens rationis,

an arbitrary fiction of thought, and not a necessary presupposition of reason. For the possibility of the

conditioned presupposes the totality of its conditions, but not of its consequences. Consequently, this

conception is not a transcendental idea and it is with these alone that we are at present occupied.

Finally, it is obvious that there exists among the transcendental ideas a certain connection and unity, and that

pure reason, by means of them, collects all its cognitions into one system. From the cognition of self to the

cognition of the world, and through these to the supreme being, the progression is so natural, that it seems to

resemble the logical march of reason from the premisses to the conclusion.* Now whether there lies

unobserved at the foundation of these ideas an analogy of the same kind as exists between the logical and

transcendental procedure of reason, is another of those questions, the answer to which we must not expect till

we arrive at a more advanced stage in our inquiries. In this cursory and preliminary view, we have,

meanwhile, reached our aim. For we have dispelled the ambiguity which attached to the transcendental

conceptions of reason, from their being commonly mixed up with other conceptions in the systems of

philosophers, and not properly distinguished from the conceptions of the understanding; we have exposed

their origin and, thereby, at the same time their determinate number, and presented them in a systematic

connection, and have thus marked out and enclosed a definite sphere for pure reason.

*The science of Metaphysics has for the proper object of its inquiries only three grand ideas: GOD,

FREEDOM, and IMMORTALITY, and it aims at showing, that the second conception, conjoined with the

first, must lead to the third, as a necessary conclusion. All the other subjects with which it occupies itself, are

merely means for the attainment and realization of these ideas. It does not require these ideas for the

construction of a science of nature, but, on the contrary, for the purpose of passing beyond the sphere of

nature. A complete insight into and comprehension of them would render Theology, Ethics, and, through the

conjunction of both, Religion, solely dependent on the speculative faculty of reason. In a systematic

representation of these ideas the abovementioned arrangement the synthetical one would be the most

suitable; but in the investigation which must necessarily precede it, the analytical, which reverses this

arrangement, would be better adapted to our purpose, as in it we should proceed from that which experience

It may be said that the object of a merely transcendental idea is something of which we have no conception,

although the idea may be a necessary product of reason according to its original laws. For, in fact, a

conception of an object that is adequate to the idea given by reason, is impossible. For such an object must be

capable of being presented and intuited in a Possible experience. But we should express our meaning better,

and with less risk of being misunderstood, if we said that we can have no knowledge of an object, which

perfectly corresponds to an idea, although we may possess a problematical conception thereof.

Now the transcendental (subjective) reality at least of the pure conceptions of reason rests upon the fact that

we are led to such ideas by a necessary procedure of reason. There must therefore be syllogisms which

contain no empirical premisses, and by means of which we conclude from something that we do know, to

something of which we do not even possess a conception, to which we, nevertheless, by an unavoidable

illusion, ascribe objective reality. Such arguments are, as regards their result, rather to be termed sophisms

than syllogisms, although indeed, as regards their origin, they are very well entitled to the latter name,

inasmuch as they are not fictions or accidental products of reason, but are necessitated by its very nature.

They are sophisms, not of men, but of pure reason herself, from which the Wisest cannot free himself. After

long labour he may be able to guard against the error, but he can never be thoroughly rid of the illusion which

Of these dialectical arguments there are three kinds, corresponding to the number of the ideas which their

conclusions present. In the argument or syllogism of the first class, I conclude, from the transcendental

conception of the subject contains no manifold, the absolute unity of the subject itself, of which I cannot in

this manner attain to a conception. This dialectical argument I shall call the transcendental paralogism. The

second class of sophistical arguments is occupied with the transcendental conception of the absolute totality

of the series of conditions for a given phenomenon, and I conclude, from the fact that I have always a

selfcontradictory conception of the unconditioned synthetical unity of the series upon one side, the truth of

the opposite unity, of which I have nevertheless no conception. The condition of reason in these dialectical

arguments, I shall term the antinomy of pure reason. Finally, according to the third kind of sophistical

argument, I conclude, from the totality of the conditions of thinking objects in general, in so far as they can

be given, the absolute synthetical unity of all conditions of the possibility of things in general; that is, from

things which I do not know in their mere transcendental conception, I conclude a being of all beings which I

know still less by means of a transcendental conception, and of whose unconditioned necessity I can form no

conception whatever. This dialectical argument I shall call the ideal of pure reason.

The logical paralogism consists in the falsity of an argument in respect of its form, be the content what it

may. But a transcendental paralogism has a transcendental foundation, and concludes falsely, while the form

is correct and unexceptionable. In this manner the paralogism has its foundation in the nature of human

reason, and is the parent of an unavoidable, though not insoluble, mental illusion.

We now come to a conception which was not inserted in the general list of transcendental conceptions. and

yet must be reckoned with them, but at the same time without in the least altering, or indicating a deficiency

in that table. This is the conception, or, if the term is preferred, the judgement, "I think." But it is readily

perceived that this thought is as it were the vehicle of all conceptions in general, and consequently of

transcendental conceptions also, and that it is therefore regarded as a transcendental conception, although it

can have no peculiar claim to be so ranked, inasmuch as its only use is to indicate that all thought is

accompanied by consciousness. At the same time, pure as this conception is from empirical content

(impressions of the senses), it enables us to distinguish two different kinds of objects. "I," as thinking, am an

object of the internal sense, and am called soul. That which is an object of the external senses is called body.

Thus the expression, "I," as a thinking being, designates the objectmatter of psychology, which may be

called "the rational doctrine of the soul," inasmuch as in this science I desire to know nothing of the soul but

what, independently of all experience (which determines me in concreto), may be concluded from this

Now, the rational doctrine of the soul is really an undertaking of this kind. For if the smallest empirical

element of thought, if any particular perception of my internal state, were to be introduced among the grounds

of cognition of this science, it would not be a rational, but an empirical doctrine of the soul. We have thus

before us a pretended science, raised upon the single proposition, "I think," whose foundation or want of

foundation we may very properly, and agreeably with the nature of a transcendental philosophy, here

examine. It ought not to be objected that in this proposition, which expresses the perception of one's self, an

internal experience is asserted, and that consequently the rational doctrine of the soul which is founded upon

it, is not pure, but partly founded upon an empirical principle. For this internal perception is nothing more

than the mere apperception, "I think," which in fact renders all transcendental conceptions possible, in which

we say, "I think substance, cause, etc." For internal experience in general and its possibility, or perception in

general, and its relation to other perceptions, unless some particular distinction or determination thereof is

empirically given, cannot be regarded as empirical cognition, but as cognition of the empirical, and belongs

to the investigation of the possibility of every experience, which is certainly transcendental. The smallest

object of experience (for example, only pleasure or pain), that should be included in the general

representation of selfconsciousness, would immediately change the rational into an empirical psychology.

"I think" is therefore the only text of rational psychology, from which it must develop its whole system. It is

manifest that this thought, when applied to an object (myself), can contain nothing but transcendental

predicates thereof; because the least empirical predicate would destroy the purity of the science and its

But we shall have to follow here the guidance of the categories only, as in the present case a thing, "I," as

thinking being, is at first given, we shall not indeed change the order of the categories as it stands in the

table but begin at the category of substance, by which at the a thing a thing is represented and proceeds

backwards through the series. The topic of the rational doctrine of the soul, from which everything else it

*The reader, who may not so easily perceive the psychological sense of these expressions, taken here in their

transcendental abstraction, and cannot guess why the latter attribute of the soul belongs to the category of

existence, will find the expressions sufficiently explained and justified in the sequel. I have, moreover, to

apologize for the Latin terms which have been employed,instead of their German synonyms, contrary to the

rules of correct writing. But I judged it better to sacrifice elegance to perspicuity.

From these elements originate all the conceptions of pure psychology, by combination alone, without the aid

of any other principle. This substance, merely as an object of the internal sense, gives the conception of

Immateriality; as simple substance, that of Incorruptibility; its identity, as intellectual substance, gives the

conception of Personality; all these three together, Spirituality. Its relation to objects in space gives us the

conception of connection (commercium) with bodies. Thus it represents thinking substance as the principle of

life in matter, that is, as a soul (anima), and as the ground of Animality; and this, limited and determined by

Now to these conceptions relate four paralogisms of a transcendental psychology, which is falsely held to be

a science of pure reason. touching the nature of our thinking being. We can, however, lay at the foundation of

this science nothing but the simple and in itself perfectly contentless representation "I which cannot even be

called a conception, but merely a consciousness which accompanies all conceptions. By this "I," or "He," or

"It," who or which thinks, nothing more is represented than a transcendental subject of thought = x, which is

cognized only by means of the thoughts that are its predicates, and of which, apart from these, we cannot

form the least conception. Hence in a perpetual circle, inasmuch as we must always employ it, in order to

frame any judgement respecting it. And this inconvenience we find it impossible to rid ourselves of, because

consciousness in itself is not so much a representation distinguishing a particular object, as a form of

representation in general, in so far as it may be termed cognition; for in and by cognition alone do I think

It must, however, appear extraordinary at first sight that the condition under which I think, and which is

consequently a property of my subject, should be held to be likewise valid for every existence which thinks,

and that we can presume to base upon a seemingly empirical proposition a judgement which is apodeictic and

universal, to wit, that everything which thinks is constituted as the voice of my consciousness declares it to

be, that is, as a selfconscious being. The cause of this belief is to be found in the fact that we necessarily

attribute to things a priori all the properties which constitute conditions under which alone we can cogitate

them. Now I cannot obtain the least representation of a thinking being by means of external experience, but

solely through selfconsciousness. Such objects are consequently nothing more than the transference of this

consciousness of mine to other things which can only thus be represented as thinking beings. The proposition,

"I think," is, in the present case, understood in a problematical sense, not in so far as it contains a perception

of an existence (like the Cartesian "Cogito, ergo sum"),* but in regard to its mere possibility for the purpose

of discovering what properties may be inferred from so simple a proposition and predicated of the subject of

If at the foundation of our pure rational cognition of thinking beings there lay more than the mere Cogito if

we could likewise call in aid observations on the play of our thoughts, and the thence derived natural laws of

the thinking self, there would arise an empirical psychology which would be a kind of physiology of the

internal sense and might possibly be capable of explaining the phenomena of that sense. But it could never be

available for discovering those properties which do not belong to possible experience (such as the quality of

simplicity), nor could it make any apodeictic enunciation on the nature of thinking beings: it would therefore

Now, as the proposition "I think" (in the problematical sense) contains the form of every judgement in

general and is the constant accompaniment of all the categories, it is manifest that conclusions are drawn

from it only by a transcendental employment of the understanding. This use of the understanding excludes all

empirical elements; and we cannot, as has been shown above, have any favourable conception beforehand of

its procedure. We shall therefore follow with a critical eye this proposition through all the predicaments of

pure psychology; but we shall, for brevity's sake, allow this examination to proceed in an uninterrupted

Before entering on this task, however, the following general remark may help to quicken our attention to this

mode of argument. It is not merely through my thinking that I cognize an object, but only through my

determining a given intuition in relation to the unity of consciousness in which all thinking consists. It

follows that I cognize myself, not through my being conscious of myself as thinking, but only when I am

conscious of the intuition of myself as determined in relation to the function of thought. All the modi of

selfconsciousness in thought are hence not conceptions of objects (conceptions of the understanding

categories); they are mere logical functions, which do not present to thought an object to be cognized, and

cannot therefore present my Self as an object. Not the consciousness of the determining, but only that of the

determinable self, that is, of my internal intuition (in so far as the manifold contained in it can be connected

conformably with the general condition of the unity of apperception in thought), is the object.

1. In all judgements I am the determining subject of that relation which constitutes a judgement. But that the I

which thinks, must be considered as in thought always a subject, and as a thing which cannot be a predicate

to thought, is an apodeictic and identical proposition. But this proposition does not signify that I, as an object,

am, for myself, a selfsubsistent being or substance. This latter statement an ambitious one requires to be

supported by data which are not to be discovered in thought; and are perhaps (in so far as I consider the

2. That the I or Ego of apperception, and consequently in all thought, is singular or simple, an;3 cannot be

resolved into a plurality of subjects, and therefore indicates a logically simple subject this is selfevident

from the very conception of an Ego, and is consequently an analytical proposition. But this is not tantamount

to declaring that the thinking Ego is a simple substance for this would be a synthetical proposition. The

conception of substance always relates to intuitions, which with me cannot be other than sensuous, and which

consequently lie completely out of the sphere of the understanding and its thought: but to this sphere belongs

the affirmation that the Ego is simple in thought. It would indeed be surprising, if the conception of

"substance," which in other cases requires so much labour to distinguish from the other elements presented by

intuition so much trouble, too, to discover whether it can be simple (as in the case of the parts of matter)

should be presented immediately to me, as if by revelation, in the poorest mental representation of all.

3. The proposition of the identity of my Self amidst all the manifold representations of which I am conscious,

is likewise a proposition lying in the conceptions themselves, and is consequently analytical. But this identity

of the subject, of which I am conscious in all its representations, does not relate to or concern the intuition of

the subject, by which it is given as an object. This proposition cannot therefore enounce the identity of the

person, by which is understood the consciousness of the identity of its own substance as a thinking being in

all change and variation of circumstances. To prove this, we should require not a mere analysis of the

4. I distinguish my own existence, as that of a thinking being, from that of other things external to me

among which my body also is reckoned. This is also an analytical proposition, for other things are exactly

those which I think as different or distinguished from myself. But whether this consciousness of myself is

possible without things external to me; and whether therefore I can exist merely as a thinking being (without

Thus we have gained nothing as regards the cognition of myself as object, by the analysis of the

consciousness of my Self in thought. The logical exposition of thought in general is mistaken for a

Our Critique would be an investigation utterly superfluous, if there existed a possibility of proving a priori,

that all thinking beings are in themselves simple substances, as such, therefore, possess the inseparable

attribute of personality, and are conscious of their existence apart from and unconnected with matter. For we

should thus have taken a step beyond the world of sense, and have penetrated into the sphere of noumena;

and in this case the right could not be denied us of extending our knowledge in this sphere, of establishing

ourselves, and, under a favouring star, appropriating to ourselves possessions in it. For the proposition:

"Every thinking being, as such, is simple substance," is an a priori synthetical proposition; because in the first

place it goes beyond the conception which is the subject of it, and adds to the mere notion of a thinking being

the mode of its existence, and in the second place annexes a predicate (that of simplicity) to the latter

conception a predicate which it could not have discovered in the sphere of experience. It would follow that a

priori synthetical propositions are possible and legitimate, not only, as we have maintained, in relation to

objects of possible experience, and as principles of the possibility of this experience itself, but are applicable

to things in themselves an inference which makes an end of the whole of this Critique, and obliges us to fall

back on the old mode of metaphysical procedure. But indeed the danger is not so great, if we look a little

There lurks in the procedure of rational Psychology a paralogism, which is represented in the following

That which cannot be cogitated otherwise than as subject, does not exist otherwise than as subject, and is

A thinking being, considered merely as such, cannot be cogitated otherwise than as subject.

In the major we speak of a being that can be cogitated generally and in every relation, consequently as it may

be given in intuition. But in the minor we speak of the same being only in so far as it regards itself as subject,

relatively to thought and the unity of consciousness, but not in relation to intuition, by which it is presented as

an object to thought. Thus the conclusion is here arrived at by a Sophisma figurae dictionis.*

*Thought is taken in the two premisses in two totally different senses. In the major it is considered as relating

and applying to objects in general, consequently to objects of intuition also. In the minor, we understand it as

relating merely to selfconsciousness. In this sense, we do not cogitate an object, but merely the relation to

the selfconsciousness of the subject, as the form of thought. In the former premiss we speak of things which

cannot be cogitated otherwise than as subjects. In the second, we do not speak of things, but of thought all

objects being abstracted), in which the Ego is always the subject of consciousness. Hence the conclusion

cannot be, "I cannot exist otherwise than as subject"; but only "I can, in cogitating my existence, employ my

Ego only as the subject of the judgement." But this is an identical proposition, and throws no light on the

That this famous argument is a mere paralogism, will be plain to any one who will consider the general

remark which precedes our exposition of the principles of the pure understanding, and the section on

noumena. For it was there proved that the conception of a thing, which can exist per se only as a subject and

never as a predicate, possesses no objective reality; that is to say, we can never know whether there exists any

object to correspond to the conception; consequently, the conception is nothing more than a conception, and

from it we derive no proper knowledge. If this conception is to indicate by the term substance, an object that

can be given, if it is to become a cognition, we must have at the foundation of the cognition a permanent

intuition, as the indispensable condition of its objective reality. For through intuition alone can an object be

given. But in internal intuition there is nothing permanent, for the Ego is but the consciousness of my

thought. If then, we appeal merely to thought, we cannot discover the necessary condition of the application

of the conception of substance that is, of a subject existing per se to the subject as a thinking being. And

thus the conception of the simple nature of substance, which is connected with the objective reality of this

conception, is shown to be also invalid, and to be, in fact, nothing more than the logical qualitative unity of

selfconsciousness in thought; whilst we remain perfectly ignorant whether the subject is composite or not.

This acute philosopher easily perceived the insufficiency of the common argument which attempts to prove

that the soul it being granted that it is a simple being cannot perish by dissolution or decomposition; he

saw it is not impossible for it to cease to be by extinction, or disappearance. He endeavoured to prove in his

Phaedo, that the soul cannot be annihilated, by showing that a simple being cannot cease to exist. Inasmuch

as, be said, a simple existence cannot diminish, nor gradually lose portions of its being, and thus be by

degrees reduced to nothing (for it possesses no parts, and therefore no multiplicity), between the moment in

which it is, and the moment in which it is not, no time can be discovered which is impossible. But this

philosopher did not consider that, granting the soul to possess this simple nature, which contains no parts

external to each other and consequently no extensive quantity, we cannot refuse to it any less than to any

other being, intensive quantity, that is, a degree of reality in regard to all its faculties, nay, to all that

constitutes its existence. But this degree of reality can become less and less through an infinite series of

smaller degrees. It follows, therefore, that this supposed substance this thing, the permanence of which is

not assured in any other way, may, if not by decomposition, by gradual loss (remissio) of its powers

(consequently by elanguescence, if I may employ this expression), be changed into nothing. For

consciousness itself has always a degree, which may be lessened.* Consequently the faculty of being

conscious may be diminished; and so with all other faculties. The permanence of the soul, therefore, as an

object of the internal sense, remains undemonstrated, nay, even indemonstrable. Its permanence in life is

evident, per se, inasmuch as the thinking being (as man) is to itself, at the same time, an object of the external

senses. But this does not authorize the rational psychologist to affirm, from mere conceptions, its permanence

*Clearness is not, as logicians maintain, the consciousness of a representation. For a certain degree of

consciousness, which may not, however, be sufficient for recollection, is to be met with in many dim

representations. For without any consciousness at all, we should not be able to recognize any difference in the

obscure representations we connect; as we really can do with many conceptions, such as those of right and

justice, and those of the musician, who strikes at once several notes in improvising a piece of music. But a

representation is clear, in which our consciousness is sufficient for the consciousness of the difference of this

representation from others. If we are only conscious that there is a difference, but are not conscious of the

difference that is, what the difference is the representation must be termed obscure. There is, consequently,

an infinite series of degrees of consciousness down to its entire disappearance.

*[2] There are some who think they have done enough to establish a new possibility in the mode of the

existence of souls, when they have shown that there is no contradiction in their hypotheses on this subject.

Such are those who affirm the possibility of thought of which they have no other knowledge than what they

derive from its use in connecting empirical intuitions presented in this our human life after this life bas

ceased. But it is very easy to embarrass them by the introduction of counterpossibilities, which rest upon

quite as good a foundation. Such, for example, is the possibility of the division of a simple substance into

several substances; and conversely, of the coalition of several into one simple substance. For, although

divisibility presupposes composition, it does not necessarily require a composition of substances, but only of

the degrees (of the several faculties) of one and the same substance. Now we can cogitate all the powers and

faculties of the soul even that of consciousness as diminished by one half, the substance still remaining. In

the same way we can represent to ourselves without contradiction, this obliterated half as preserved, not in

the soul, but without it; and we can believe that, as in this case every. thing that is real in the soul, and has a

degree consequently its entire existence has been halved, a particular substance would arise out of the soul.

For the multiplicity, which has been divided, formerly existed, but not as a multiplicity of substances, but of

every reality as the quantum of existence in it; and the unity of substance was merely a mode of existence,

which by this division alone has been transformed into a plurality of subsistence. In the same manner several

simple substances might coalesce into one, without anything being lost except the plurality of subsistence,

inasmuch as the one substance would contain the degree of reality of all the former substances. Perhaps,

indeed, the simple substances, which appear under the form of matter, might (not indeed by a mechanical or

chemical influence upon each other, but by an unknown influence, of which the former would be but the

phenomenal appearance), by means of such a dynamical division of the parentsouls, as intensive quantities,

produce other souls, while the former repaired the loss thus sustained with new matter of the same sort. I am

far from allowing any value to such chimeras; and the principles of our analytic have clearly proved that no

other than an empirical use of the categories that of substance, for example is possible. But if the

rationalist is bold enough to construct, on the mere authority of the faculty of thought without any intuition,

whereby an object is given a selfsubsistent being, merely because the unity of apperception in thought

cannot allow him to believe it a composite being, instead of declaring, as he ought to do, that he is unable to

explain the possibility of a thinking nature; what ought to hinder the materialist, with as complete an

independence of experience, to employ the principle of the rationalist in a directly opposite manner still

If, now, we take the above propositions as they must be accepted as valid for all thinking beings in the

system of rational psychology in synthetical connection, and proceed, from the category of relation, with the

proposition: "All thinking beings are, as such, substances," backwards through the series, till the circle is

completed; we come at last to their existence, of which, in this system of rational psychology, substances are

held to be conscious, independently of external things; nay, it is asserted that, in relation to the permanence

which is a necessary characteristic of substance, they can of themselves determine external things. It follows

that idealism at least problematical idealism, is perfectly unavoidable in this rationalistic system. And, if the

existence of outward things is not held to be requisite to the determination of the existence of a substance in

time, the existence of these outward things at all, is a gratuitous assumption which remains without the

But if we proceed analytically the "I think" as a proposition containing in itself an existence as given,

consequently modality being the principle and dissect this proposition, in order to ascertain its content, and

discover whether and how this Ego determines its existence in time and space without the aid of anything

external; the propositions of rationalistic psychology would not begin with the conception of a thinking

being, but with a reality, and the properties of a thinking being in general would be deduced from the mode in

which this reality is cogitated, after everything empirical had been abstracted; as is shown in the following

Now, inasmuch as it is not determined in this second proposition, whether I can exist and be cogitated only as

subject, and not also as a predicate of another being, the conception of a subject is here taken in a merely

logical sense; and it remains undetermined, whether substance is to be cogitated under the conception or not.

But in the third proposition, the absolute unity of apperception the simple Ego in the representation to which

all connection and separation, which constitute thought, relate, is of itself important; even although it presents

us with no information about the constitution or subsistence of the subject. Apperception is something real,

and the simplicity of its nature is given in the very fact of its possibility. Now in space there is nothing real

that is at the same time simple; for points, which are the only simple things in space, are merely limits, but

not constituent parts of space. From this follows the impossibility of a definition on the basis of materialism

of the constitution of my Ego as a merely thinking subject. But, because my existence is considered in the

first proposition as given, for it does not mean, "Every thinking being exists" (for this would be predicating of

them absolute necessity), but only, "I exist thinking"; the proposition is quite empirical, and contains the

determinability of my existence merely in relation to my representations in time. But as I require for this

purpose something that is permanent, such as is not given in internal intuition; the mode of my existence,

whether as substance or as accident, cannot be determined by means of this simple selfconsciousness. Thus,

if materialism is inadequate to explain the mode in which I exist, spiritualism is likewise as insufficient; and

the conclusion is that we are utterly unable to attain to any knowledge of the constitution of the soul, in so far

And, indeed, how should it be possible, merely by the aid of the unity of consciousness which we cognize

only for the reason that it is indispensable to the possibility of experience to pass the bounds of experience

(our existence in this life); and to extend our cognition to the nature of all thinking beings by means of the

empirical but in relation to every sort of intuition, perfectly undetermined proposition, "I think"?

There does not then exist any rational psychology as a doctrine furnishing any addition to our knowledge of

ourselves. It is nothing more than a discipline, which sets impassable limits to speculative reason in this

region of thought, to prevent it, on the one hand, from throwing itself into the arms of a soulless materialism,

and, on the other, from losing itself in the mazes of a baseless spiritualism. It teaches us to consider this

refusal of our reason to give any satisfactory answer to questions which reach beyond the limits of this our

human life, as a hint to abandon fruitless speculation; and to direct, to a practical use, our knowledge of

ourselves which, although applicable only to objects of experience, receives its principles from a higher

source, and regulates its procedure as if our destiny reached far beyond the boundaries of experience and life.

From all this it is evident that rational psychology has its origin in a mere misunderstanding. The unity of

consciousness, which lies at the basis of the categories, is considered to be an intuition of the subject as an

object; and the category of substance is applied to the intuition. But this unity is nothing more than the unity

in thought, by which no object is given; to which therefore the category of substance which always

presupposes a given intuition cannot be applied. Consequently, the subject cannot be cognized. The subject

of the categories cannot, therefore, for the very reason that it cogitates these, frame any conception of itself as

an object of the categories; for, to cogitate these, it must lay at the foundation its own pure

selfconsciousness the very thing that it wishes to explain and describe. In like manner, the subject, in

which the representation of time has its basis, cannot determine, for this very reason, its own existence in

time. Now, if the latter is impossible, the former, as an attempt to determine itself by means of the categories

*The "I think" is, as has been already stated, an empirical proposition, and contains the proposition, "I exist."

But I cannot say, "Everything, which thinks, exists"; for in this case the property of thought would constitute

all beings possessing it, necessary being Hence my existence cannot be considered as an inference from the

proposition, "I think," as Descartes maintained because in this case the major premiss, "Everything, which

thinks, exists," must precede but the two propositions are identical. The proposition, "I think," expresses an

undetermined empirical intuition, that perception (proving consequently that sensation, which must belong to

sensibility, lies at the foundation of this proposition); but it precedes experience, whose province it is to

determine an object of perception by means of the categories in relation to time; and existence in this

proposition is not a category, as it does not apply to an undetermined given object, but only to one of which

we have a conception, and about which we wish to know whether it does or does not exist, out of, and apart

from this conception. An undetermined perception signifies here merely something real that has been given,

only, however, to thought in general but not as a phenomenon, nor as a thing in itself (noumenon), but only

as something that really exists, and is designated as such in the proposition, "I think." For it must be remarked

that, when I call the proposition, "I think," an empirical proposition, I do not thereby mean that the Ego in the

proposition is an empirical representation; on the contrary, it is purely intellectual, because it belongs to

thought in general. But without some empirical representation, which presents to the mind material for

thought, the mental act, "I think," would not take place; and the empirical is only the condition of the

Thus, then, appears the vanity of the hope of establishing a cognition which is to extend its rule beyond the

limits of experience a cognition which is one of the highest interests of humanity; and thus is proved the

futility of the attempt of speculative philosophy in this region of thought. But, in this interest of thought, the

severity of criticism has rendered to reason a not unimportant service, by the demonstration of the

impossibility of making any dogmatical affirmation concerning an object of experience beyond the

boundaries of experience. She has thus fortified reason against all affirmations of the contrary. Now, this can

be accomplished in only two ways. Either our proposition must be proved apodeictically; or, if this is

unsuccessful, the sources of this inability must be sought for, and, if these are discovered to exist in the

natural and necessary limitation of our reason, our opponents must submit to the same law of renunciation

But the right, say rather the necessity to admit a future life, upon principles of the practical conjoined with the

speculative use of reason, has lost nothing by this renunciation; for the merely speculative proof has never

had any influence upon the common reason of men. It stands upon the point of a hair, so that even the schools

have been able to preserve it from falling only by incessantly discussing it and spinning it like a top; and even

in their eyes it has never been able to present any safe foundation for the erection of a theory. The proofs

which have been current among men, preserve their value undiminished; nay, rather gain in clearness and

unsophisticated power, by the rejection of the dogmatical assumptions of speculative reason. For reason is

thus confined within her own peculiar province the arrangement of ends or aims, which is at the same time

the arrangement of nature; and, as a practical faculty, without limiting itself to the latter, it is justified in

extending the former, and with it our own existence, beyond the boundaries of experience and life. If we turn

our attention to the analogy of the nature of living beings in this world, in the consideration of which reason

is obliged to accept as a principle that no organ, no faculty, no appetite is useless, and that nothing is

superfluous, nothing disproportionate to its use, nothing unsuited to its end; but that, on the contrary,

everything is perfectly conformed to its destination in life we shall find that man, who alone is the final end

and aim of this order, is still the only animal that seems to be excepted from it. For his natural gifts not

merely as regards the talents and motives that may incite him to employ them, but especially the moral law in

him stretch so far beyond all mere earthly utility and advantage, that he feels himself bound to prize the

mere consciousness of probity, apart from all advantageous consequences even the shadowy gift of

posthumous fame above everything; and he is conscious of an inward call to constitute himself, by his

conduct in this world without regard to mere sublunary interests the citizen of a better. This mighty,

irresistible proof accompanied by an everincreasing knowledge of the conformability to a purpose in

everything we see around us, by the conviction of the boundless immensity of creation, by the consciousness

of a certain illimitableness in the possible extension of our knowledge, and by a desire commensurate

therewith remains to humanity, even after the theoretical cognition of ourselves bas failed to establish the

The dialectical illusion in rational psychology arises from our confounding an idea of reason (of a pure

intelligence) with the conception in every respect undetermined of a thinking being in general. I cogitate

myself in behalf of a possible experience, at the same time making abstraction of all actual experience; and

infer therefrom that I can be conscious of myself apart from experience and its empirical conditions. I

consequently confound the possible abstraction of my empirically determined existence with the supposed

consciousness of a possible separate existence of my thinking self; and I believe that I cognize what is

substantial in myself as a transcendental subject, when I have nothing more in thought than the unity of

The task of explaining the community of the soul with the body does not properly belong to the psychology

of which we are here speaking; because it proposes to prove the personality of the soul apart from this

communion (after death), and is therefore transcendent in the proper sense of the word, although occupying

itself with an object of experience only in so far, however, as it ceases to be an object of experience. But a

sufficient answer may be found to the question in our system. The difficulty which lies in the execution of

this task consists, as is well known, in the presupposed heterogeneity of the object of the internal sense (the

soul) and the objects of the external senses; inasmuch as the formal condition of the intuition of the one is

time, and of that of the other space also. But if we consider that both kinds of objects do not differ internally,

but only in so far as the one appears externally to the other consequently, that what lies at the basis of

phenomena, as a thing in itself, may not be heterogeneous; this difficulty disappears. There then remains no

other difficulty than is to be found in the question how a community of substances is possible; a question

which lies out of the region of psychology, and which the reader, after what in our analytic has been said of

primitive forces and faculties, will easily judge to be also beyond the region of human cognition.

The proposition, "I think," or, "I exist thinking," is an empirical proposition. But such a proposition must be

based on empirical intuition, and the object cogitated as a phenomenon; and thus our theory appears to

maintain that the soul, even in thought, is merely a phenomenon; and in this way our consciousness itself, in

Thought, per se, is merely the purely spontaneous logical function which operates to connect the manifold of

a possible intuition; and it does not represent the subject of consciousness as a phenomenon for this reason

alone, that it pays no attention to the question whether the mode of intuiting it is sensuous or intellectual. I

therefore do not represent myself in thought either as I am, or as I appear to myself; I merely cogitate myself

as an object in general, of the mode of intuiting which I make abstraction. When I represent myself as the

subject of thought, or as the ground of thought, these modes of representation are not related to the categories

of substance or of cause; for these are functions of thought applicable only to our sensuous intuition. The

application of these categories to the Ego would, however, be necessary, if I wished to make myself an object

of knowledge. But I wish to be conscious of myself only as thinking; in what mode my Self is given in

intuition, I do not consider, and it may be that I, who think, am a phenomenon although not in so far as I am

a thinking being; but in the consciousness of myself in mere thought I am a being, though this consciousness

But the proposition, "I think," in so far as it declares, "I exist thinking," is not the mere representation of a

logical function. It determines the subject (which is in this case an object also) in relation to existence; and it

cannot be given without the aid of the internal sense, whose intuition presents to us an object, not as a thing

in itself, but always as a phenomenon. In this proposition there is therefore something more to be found than

the mere spontaneity of thought; there is also the receptivity of intuition, that is, my thought of myself applied

to the empirical intuition of myself. Now, in this intuition the thinking self must seek the conditions of the

employment of its logical functions as categories of substance, cause, and so forth; not merely for the purpose

of distinguishing itself as an object in itself by means of the representation "I," but also for the purpose of

determining the mode of its existence, that is, of cognizing itself as noumenon. But this is impossible, for the

internal empirical intuition is sensuous, and presents us with nothing but phenomenal data, which do not

assist the object of pure consciousness in its attempt to cognize itself as a separate existence, but are useful

But, let it be granted that we could discover, not in experience, but in certain firmlyestablished a priori laws

of the use of pure reason laws relating to our existence, authority to consider ourselves as legislating a priori

in relation to our own existence and as determining this existence; we should, on this supposition, find

ourselves possessed of a spontaneity, by which our actual existence would be determinable, without the aid of

the conditions of empirical intuition. We should also become aware that in the consciousness of our existence

there was an a priori content, which would serve to determine our own existence an existence only

sensuously determinable relatively, however, to a certain internal faculty in relation to an intelligible world.

But this would not give the least help to the attempts of rational psychology. For this wonderful faculty,

which the consciousness of the moral law in me reveals, would present me with a principle of the

determination of my own existence which is purely intellectual but by what predicates? By none other than

those which are given in sensuous intuition. Thus I should find myself in the same position in rational

psychology which I formerly occupied, that is to say, I should find myself still in need of sensuous intuitions,

in order to give significance to my conceptions of substance and cause, by means of which alone I can

possess a knowledge of myself: but these intuitions can never raise me above the sphere of experience. I

should be justified, however, in applying these conceptions, in regard to their practical use, which is always

directed to objects of experience in conformity with their analogical significance when employed

theoretically to freedom and its subject. At the same time, I should understand by them merely the logical

functions of subject and predicate, of principle and consequence, in conformity with which all actions are so

determined, that they are capable of being explained along with the laws of nature, conformably to the

categories of substance and cause, although they originate from a very different principle. We have made

these observations for the purpose of guarding against misunderstanding, to which the doctrine of our

intuition of self as a phenomenon is exposed. We shall have occasion to perceive their utility in the sequel.

We showed in the introduction to this part of our work, that all transcendental illusion of pure reason arose

from dialectical arguments, the schema of which logic gives us in its three formal species of syllogisms just

as the categories find their logical schema in the four functions of all judgements. The first kind of these

sophistical arguments related to the unconditioned unity of the subjective conditions of all representations in

general (of the subject or soul), in correspondence with the categorical syllogisms, the major of which, as the

principle, enounces the relation of a predicate to a subject. The second kind of dialectical argument will

therefore be concerned, following the analogy with hypothetical syllogisms, with the unconditioned unity of

the objective conditions in the phenomenon; and, in this way, the theme of the third kind to be treated of in

the following chapter will be the unconditioned unity of the objective conditions of the possibility of objects

But it is worthy of remark that the transcendental paralogism produced in the mind only a onethird illusion,

in regard to the idea of the subject of our thought; and the conceptions of reason gave no ground to maintain

the contrary proposition. The advantage is completely on the side of Pneumatism; although this theory itself

Very different is the case when we apply reason to the objective synthesis of phenomena. Here, certainly,

reason establishes, with much plausibility, its principle of unconditioned unity; but it very soon falls into such

contradictions that it is compelled, in relation to cosmology, to renounce its pretensions.

For here a new phenomenon of human reason meets us a perfectly natural antithetic, which does not require

to be sought for by subtle sophistry, but into which reason of itself unavoidably falls. It is thereby preserved,

to be sure, from the slumber of a fancied conviction which a merely onesided illusion produces; but it is at

the same time compelled, either, on the one hand, to abandon itself to a despairing scepticism, or, on the

other, to assume a dogmatical confidence and obstinate persistence in certain assertions, without granting a

fair hearing to the other side of the question. Either is the death of a sound philosophy, although the former

Before entering this region of discord and confusion, which the conflict of the laws of pure reason (antinomy)

produces, we shall present the reader with some considerations, in explanation and justification of the method

we intend to follow in our treatment of this subject. I term all transcendental ideas, in so far as they relate to

the absolute totality in the synthesis of phenomena, cosmical conceptions; partly on account of this

unconditioned totality, on which the conception of the worldwhole is based a conception, which is itself an

idea partly because they relate solely to the synthesis of phenomena the empirical synthesis; while, on the

other hand, the absolute totality in the synthesis of the conditions of all possible things gives rise to an ideal

of pure reason, which is quite distinct from the cosmical conception, although it stands in relation with it.

Hence, as the paralogisms of pure reason laid the foundation for a dialectical psychology, the antinomy of

pure reason will present us with the transcendental principles of a pretended pure (rational) cosmology not,

however, to declare it valid and to appropriate it, but as the very term of a conflict of reason sufficiently

indicates, to present it as an idea which cannot be reconciled with phenomena and experience.

That We may be able to enumerate with systematic precision these ideas according to a principle, we must

remark, in the first place, that it is from the understanding alone that pure and transcendental conceptions take

their origin; that the reason does not properly give birth to any conception, but only frees the conception of

the understanding from the unavoidable limitation of a possible experience, and thus endeavours to raise it

above the empirical, though it must still be in connection with it. This happens from the fact that, for a given

conditioned, reason demands absolute totality on the side of the conditions (to which the understanding

submits all phenomena), and thus makes of the category a transcendental idea. This it does that it may be able

to give absolute completeness to the empirical synthesis, by continuing it to the unconditioned (which is not

to be found in experience, but only in the idea). Reason requires this according to the principle: If the

conditioned is given the whole of the conditions, and consequently the absolutely unconditioned, is also

given, whereby alone the former was possible. First, then, the transcendental ideas are properly nothing but

categories elevated to the unconditioned; and they may be arranged in a table according to the titles of the

latter. But, secondly, all the categories are not available for this purpose, but only those in which the synthesis

constitutes a series of conditions subordinated to, not coordinated with, each other. Absolute totality is

required of reason only in so far as concerns the ascending series of the conditions of a conditioned; not,

consequently, when the question relates to the descending series of consequences, or to the aggregate of the

coordinated conditions of these consequences. For, in relation to a given conditioned, conditions are

presupposed and considered to be given along with it. On the other hand, as the consequences do not render

possible their conditions, but rather presuppose them in the consideration of the procession of consequences

(or in the descent from the given condition to the conditioned), we may be quite unconcerned whether the

Thus we cogitate and necessarily a given time completely elapsed up to a given moment, although that

time is not determinable by us. But as regards time future, which is not the condition of arriving at the

present, in order to conceive it; it is quite indifferent whether we consider future time as ceasing at some

point, or as prolonging itself to infinity. Take, for example, the series m, n, o, in which n is given as

conditioned in relation to m, but at the same time as the condition of o, and let the series proceed upwards

from the conditioned n to m (l, k, i, etc.), and also downwards from the condition n to the conditioned o (p, q,

r, etc.) I must presuppose the former series, to be able to consider n as given, and n is according to reason

(the totality of conditions) possible only by means of that series. But its possibility does not rest on the

following series o, p, q, r, which for this reason cannot be regarded as given, but only as capable of being

I shall term the synthesis of the series on the side of the conditions from that nearest to the given

phenomenon up to the more remote regressive; that which proceeds on the side of the conditioned, from the

immediate consequence to the more remote, I shall call the progressive synthesis. The former proceeds in

antecedentia, the latter in consequentia. The cosmological ideas are therefore occupied with the totality of the

regressive synthesis, and proceed in antecedentia, not in consequentia. When the latter takes place, it is an

arbitrary and not a necessary problem of pure reason; for we require, for the complete understanding of what

is given in a phenomenon, not the consequences which succeed, but the grounds or principles which precede.

In order to construct the table of ideas in correspondence with the table of categories, we take first the two

primitive quanta of all our intuitions, time and space. Time is in itself a series (and the formal condition of all

series), and hence, in relation to a given present, we must distinguish a priori in it the antecedentia as

conditions (time past) from the consequentia (time future). Consequently, the transcendental idea of the

absolute totality of the series of the conditions of a given conditioned, relates merely to all past time.

According to the idea of reason, the whole past time, as the condition of the given moment, is necessarily

cogitated as given. But, as regards space, there exists in it no distinction between progressus and regressus;

for it is an aggregate and not a series its parts existing together at the same time. I can consider a given point

of time in relation to past time only as conditioned, because this given moment comes into existence only

through the past time rather through the passing of the preceding time. But as the parts of space are not

subordinated, but coordinated to each other, one part cannot be the condition of the possibility of the other;

and space is not in itself, like time, a series. But the synthesis of the manifold parts of space (the syntheses

whereby we apprehend space) is nevertheless successive; it takes place, therefore, in time, and contains a

series. And as in this series of aggregated spaces (for example, the feet in a rood), beginning with a given

portion of space, those which continue to be annexed form the condition of the limits of the former the

measurement of a space must also be regarded as a synthesis of the series of the conditions of a given

conditioned. It differs, however, in this respect from that of time, that the side of the conditioned is not in

itself distinguishable from the side of the condition; and, consequently, regressus and progressus in space

seem to be identical. But, inasmuch as one part of space is not given, but only limited, by and through

another, we must also consider every limited space as conditioned, in so far as it presupposes some other

space as the condition of its limitation, and so on. As regards limitation, therefore, our procedure in space is

also a regressus, and the transcendental idea of the absolute totality of the synthesis in a series of conditions

applies to space also; and I am entitled to demand the absolute totality of the phenomenal synthesis in space

as well as in time. Whether my demand can be satisfied is a question to be answered in the sequel.

Secondly, the real in space that is, matter is conditioned. Its internal conditions are its parts, and the parts

of parts its remote conditions; so that in this case we find a regressive synthesis, the absolute totality of which

is a demand of reason. But this cannot be obtained otherwise than by a complete division of parts, whereby

the real in matter becomes either nothing or that which is not matter, that is to say, the simple. Consequently

Thirdly, as regards the categories of a real relation between phenomena, the category of substance and its

accidents is not suitable for the formation of a transcendental idea; that is to say, reason has no ground, in

regard to it, to proceed regressively with conditions. For accidents (in so far as they inhere in a substance) are

coordinated with each other, and do not constitute a series. And, in relation to substance, they are not

properly subordinated to it, but are the mode of existence of the substance itself. The conception of the

substantial might nevertheless seem to be an idea of the transcendental reason. But, as this signifies nothing

more than the conception of an object in general, which subsists in so far as we cogitate in it merely a

transcendental subject without any predicates; and as the question here is of an unconditioned in the series of

phenomena it is clear that the substantial can form no member thereof. The same holds good of substances

in community, which are mere aggregates and do not form a series. For they are not subordinated to each

other as conditions of the possibility of each other; which, however, may be affirmed of spaces, the limits of

which are never determined in themselves, but always by some other space. It is, therefore, only in the

category of causality that we can find a series of causes to a given effect, and in which we ascend from the

latter, as the conditioned, to the former as the conditions, and thus answer the question of reason.

Fourthly, the conceptions of the possible, the actual, and the necessary do not conduct us to any series

excepting only in so far as the contingent in existence must always be regarded as conditioned, and as

indicating, according to a law of the understanding, a condition, under which it is necessary to rise to a

higher, till in the totality of the series, reason arrives at unconditioned necessity.

There are, accordingly, only four cosmological ideas, corresponding with the four titles of the categories. For

we can select only such as necessarily furnish us with a series in the synthesis of the manifold.

We must here remark, in the first place, that the idea of absolute totality relates to nothing but the exposition

of phenomena, and therefore not to the pure conception of a totality of things. Phenomena are here, therefore,

regarded as given, and reason requires the absolute completeness of the conditions of their possibility, in so

far as these conditions constitute a series consequently an absolutely (that is, in every respect) complete

synthesis, whereby a phenomenon can be explained according to the laws of the understanding.

Secondly, it is properly the unconditioned alone that reason seeks in this serially and regressively conducted

synthesis of conditions. It wishes, to speak in another way, to attain to completeness in the series of

premisses, so as to render it unnecessary to presuppose others. This unconditioned is always contained in the

absolute totality of the series, when we endeavour to form a representation of it in thought. But this

absolutely complete synthesis is itself but an idea; for it is impossible, at least before hand, to know whether

any such synthesis is possible in the case of phenomena. When we represent all existence in thought by

means of pure conceptions of the understanding, without any conditions of sensuous intuition, we may say

with justice that for a given conditioned the whole series of conditions subordinated to each other is also

given; for the former is only given through the latter. But we find in the case of phenomena a particular

limitation of the mode in which conditions are given, that is, through the successive synthesis of the manifold

of intuition, which must be complete in the regress. Now whether this completeness is sensuously possible, is

a problem. But the idea of it lies in the reason be it possible or impossible to connect with the idea adequate

empirical conceptions. Therefore, as in the absolute totality of the regressive synthesis of the manifold in a

phenomenon (following the guidance of the categories, which represent it as a series of conditions to a given

conditioned) the unconditioned is necessarily contained it being still left unascertained whether and how this

totality exists; reason sets out from the idea of totality, although its proper and final aim is the

This unconditioned may be cogitated either as existing only in the entire series, all the members of which

therefore would be without exception conditioned and only the totality absolutely unconditioned and in this

case the regressus is called infinite; or the absolutely unconditioned is only a part of the series, to which the

other members are subordinated, but which Is not itself submitted to any other condition.* In the former case

the series is a parte priori unlimited (without beginning), that is, infinite, and nevertheless completely given.

But the regress in it is never completed, and can only be called potentially infinite. In the second case there

exists a first in the series. This first is called, in relation to past time, the beginning of the world; in relation to

space, the limit of the world; in relation to the parts of a given limited whole, the simple; in relation to causes,

absolute spontaneity (liberty); and in relation to the existence of changeable things, absolute physical

*The absolute totality of the series of conditions to a given conditioned is always unconditioned; because

beyond it there exist no other conditions, on which it might depend. But the absolute totality of such a series

is only an idea, or rather a problematical conception, the possibility of which must be investigated

particularly in relation to the mode in which the unconditioned, as the transcendental idea which is the real

We possess two expressions, world and nature, which are generally interchanged. The first denotes the

mathematical total of all phenomena and the totality of their synthesis in its progress by means of

composition, as well as by division. And the world is termed nature,* when it is regarded as a dynamical

whole when our attention is not directed to the aggregation in space and time, for the purpose of cogitating

it as a quantity, but to the unity in the existence of phenomena. In this case the condition of that which

happens is called a cause; the unconditioned causality of the cause in a phenomenon is termed liberty; the

conditioned cause is called in a more limited sense a natural cause. The conditioned in existence is termed

contingent, and the unconditioned necessary. The unconditioned necessity of phenomena may be called

*Nature, understood adjective (formaliter), signifies the complex of the determinations of a thing, connected

according to an internal principle of causality. On the other hand, we understand by nature, substantive

(materialiter), the sum total of phenomena, in so far as they, by virtue of an internal principle of causality, are

connected with each other throughout. In the former sense we speak of the nature of liquid matter, of fire,

etc., and employ the word only adjective; while, if speaking of the objects of nature, we have in our minds the

The ideas which we are at present engaged in discussing I have called cosmological ideas; partly because by

the term world is understood the entire content of all phenomena, and our ideas are directed solely to the

unconditioned among phenomena; partly also, because world, in the transcendental sense, signifies the

absolute totality of the content of existing things, and we are directing our attention only to the completeness

of the synthesis although, properly, only in regression. In regard to the fact that these ideas are all

transcendent. and, although they do not transcend phenomena as regards their mode, but are concerned solely

with the world of sense (and not with noumena), nevertheless carry their synthesis to a degree far above all

possible experience it still seems to me that we can, with perfect propriety, designate them cosmical

conceptions. As regards the distinction between the mathematically and the dynamically unconditioned which

is the aim of the regression of the synthesis, I should call the two former, in a more limited signification,

cosmical conceptions, the remaining two transcendent physical conceptions. This distinction does not at

present seem to be of particular importance, but we shall afterwards find it to be of some value.

Thetic is the term applied to every collection of dogmatical propositions. By antithetic I do not understand

dogmatical assertions of the opposite, but the selfcontradiction of seemingly dogmatical cognitions (thesis

cum antithesis, in none of which we can discover any decided superiority. Antithetic is not, therefore,

occupied with onesided statements, but is engaged in considering the contradictory nature of the general

cognitions of reason and its causes. Transcendental antithetic is an investigation into the antinomy of pure

reason, its causes and result. If we employ our reason not merely in the application of the principles of the

understanding to objects of experience, but venture with it beyond these boundaries, there arise certain

sophistical propositions or theorems. These assertions have the following peculiarities: They can find neither

confirmation nor confutation in experience; and each is in itself not only selfconsistent, but possesses

conditions of its necessity in the very nature of reason only that, unluckily, there exist just as valid and

The questions which naturally arise in the consideration of this dialectic of pure reason, are therefore: 1st. In

what propositions is pure reason unavoidably subject to an antinomy? 2nd. What are the causes of this

antinomy? 3rd. Whether and in what way can reason free itself from this selfcontradiction?

A dialectical proposition or theorem of pure reason must, according to what has been said, be distinguishable

from all sophistical propositions, by the fact that it is not an answer to an arbitrary question, which may be

raised at the mere pleasure of any person, but to one which human reason must necessarily encounter in its

progress. In the second place, a dialectical proposition, with its opposite, does not carry the appearance of a

merely artificial illusion, which disappears as soon as it is investigated, but a natural and unavoidable

illusion, which, even when we are no longer deceived by it, continues to mock us and, although rendered

This dialectical doctrine will not relate to the unity of understanding in empirical conceptions, but to the unity

of reason in pure ideas. The conditions of this doctrine are inasmuch as it must, as a synthesis according to

rules, be conformable to the understanding, and at the same time as the absolute unity of the synthesis, to the

reason that, if it is adequate to the unity of reason, it is too great for the understanding, if according with the

understanding, it is too small for the reason. Hence arises a mutual opposition, which cannot be avoided, do

These sophistical assertions of dialectic open, as it were, a battlefield, where that side obtains the victory

which has been permitted to make the attack, and he is compelled to yield who has been unfortunately

obliged to stand on the defensive. And hence, champions of ability, whether on the right or on the wrong side,

are certain to carry away the crown of victory, if they only take care to have the right to make the last attack,

and are not obliged to sustain another onset from their opponent. We can easily believe that this arena has

been often trampled by the feet of combatants, that many victories have been obtained on both sides, but that

the last victory, decisive of the affair between the contending parties, was won by him who fought for the

right, only if his adversary was forbidden to continue the tourney. As impartial umpires, we must lay aside

entirely the consideration whether the combatants are fighting for the right or for the wrong side, for the true

or for the false, and allow the combat to be first decided. Perhaps, after they have wearied more than injured

each other, they will discover the nothingness of their cause of quarrel and part good friends.

This method of watching, or rather of originating, a conflict of assertions, not for the purpose of finally

deciding in favour of either side, but to discover whether the object of the struggle is not a mere illusion,

which each strives in vain to reach, but which would be no gain even when reached this procedure, I say,

may be termed the sceptical method. It is thoroughly distinct from scepticism the principle of a technical

and scientific ignorance, which undermines the foundations of all knowledge, in order, if possible, to destroy

our belief and confidence therein. For the sceptical method aims at certainty, by endeavouring to discover in a

conflict of this kind, conducted honestly and intelligently on both sides, the point of misunderstanding; just as

wise legislators derive, from the embarrassment of judges in lawsuits, information in regard to the defective

and illdefined parts of their statutes. The antinomy which reveals itself in the application of laws, is for our

limited wisdom the best criterion of legislation. For the attention of reason, which in abstract speculation does

not easily become conscious of its errors, is thus roused to the momenta in the determination of its principles.

But this sceptical method is essentially peculiar to transcendental philosophy, and can perhaps be dispensed

with in every other field of investigation. In mathematics its use would be absurd; because in it no false

assertions can long remain hidden, inasmuch as its demonstrations must always proceed under the guidance

of pure intuition, and by means of an always evident synthesis. In experimental philosophy, doubt and delay

may be very useful; but no misunderstanding is possible, which cannot be easily removed; and in experience

means of solving the difficulty and putting an end to the dissension must at last be found, whether sooner or

later. Moral philosophy can always exhibit its principles, with their practical consequences, in concreto at

least in possible experiences, and thus escape the mistakes and ambiguities of abstraction. But transcendental

propositions, which lay claim to insight beyond the region of possible experience, cannot, on the one hand,

exhibit their abstract synthesis in any a priori intuition, nor, on the other, expose a lurking error by the help of

experience. Transcendental reason, therefore, presents us with no other criterion than that of an attempt to

reconcile such assertions, and for this purpose to permit a free and unrestrained conflict between them. And

*The antinomies stand in the order of the four transcendental ideas above detailed.

Granted that the world has no beginning in time; up to every given moment of time, an eternity must have

elapsed, and therewith passed away an infinite series of successive conditions or states of things in the world.

Now the infinity of a series consists in the fact that it never can be completed by means of a successive

synthesis. It follows that an infinite series already elapsed is impossible and that, consequently, a beginning

of the world is a necessary condition of its existence. And this was the first thing to be proved.

As regards the second, let us take the opposite for granted. In this case, the world must be an infinite given

total of coexistent things. Now we cannot cogitate the dimensions of a quantity, which is not given within

certain limits of an intuition,* in any other way than by means of the synthesis of its parts, and the total of

such a quantity only by means of a completed synthesis, or the repeated addition of unity to itself.

Accordingly, to cogitate the world, which fills all spaces, as a whole, the successive synthesis of the parts of

an infinite world must be looked upon as completed, that is to say, an infinite time must be regarded as

having elapsed in the enumeration of all coexisting things; which is impossible. For this reason an infinite

aggregate of actual things cannot be considered as a given whole, consequently, not as a contemporaneously

given whole. The world is consequently, as regards extension in space, not infinite, but enclosed in limits.

*We may consider an undetermined quantity as a whole, when it is enclosed within limits, although we

cannot construct or ascertain its totality by measurement, that is, by the successive synthesis of its parts. For

The world has no beginning, and no limits in space, but is, in relation both to time and space, infinite.

For let it be granted that it has a beginning. A beginning is an existence which is preceded by a time in which

the thing does not exist. On the above supposition, it follows that there must have been a time in which the

world did not exist, that is, a void time. But in a void time the origination of a thing is impossible; because no

part of any such time contains a distinctive condition of being, in preference to that of nonbeing (whether

the supposed thing originate of itself, or by means of some other cause). Consequently, many series of things

may have a beginning in the world, but the world itself cannot have a beginning, and is, therefore, in relation

As regards the second statement, let us first take the opposite for granted that the world is finite and limited

in space; it follows that it must exist in a void space, which is not limited. We should therefore meet not only

with a relation of things in space, but also a relation of things to space. Now, as the world is an absolute

whole, out of and beyond which no object of intuition, and consequently no correlate to which can be

discovered, this relation of the world to a void space is merely a relation to no object. But such a relation, and

consequently the limitation of the world by void space, is nothing. Consequently, the world, as regards space,

*Space is merely the form of external intuition (formal intuition), and not a real object which can be

externally perceived. Space, prior to all things which determine it (fill or limit it), or, rather, which present an

empirical intuition conformable to it, is, under the title of absolute space, nothing but the mere possibility of

external phenomena, in so far as they either exist in themselves, or can annex themselves to given intuitions.

Empirical intuition is therefore not a composition of phenomena and space (of perception and empty

intuition). The one is not the correlate of the other in a synthesis, but they are vitally connected in the same

empirical intuition, as matter and form. If we wish to set one of these two apart from the other space from

phenomena there arise all sorts of empty determinations of external intuition, which are very far from being

possible perceptions. For example, motion or rest of the world in an infinite empty space, or a determination

of the mutual relation of both, cannot possibly be perceived, and is therefore merely the predicate of a

In bringing forward these conflicting arguments, I have not been on the search for sophisms, for the purpose

of availing myself of special pleading, which takes advantage of the carelessness of the opposite party,

appeals to a misunderstood statute, and erects its unrighteous claims upon an unfair interpretation. Both

proofs originate fairly from the nature of the case, and the advantage presented by the mistakes of the

The thesis might also have been unfairly demonstrated, by the introduction of an erroneous conception of the

infinity of a given quantity. A quantity is infinite, if a greater than itself cannot possibly exist. The quantity is

measured by the number of given units which are taken as a standard contained in it. Now no number can

be the greatest, because one or more units can always be added. It follows that an infinite given quantity,

consequently an infinite world (both as regards time and extension) is impossible. It is, therefore, limited in

both respects. In this manner I might have conducted my proof; but the conception given in it does not agree

with the true conception of an infinite whole. In this there is no representation of its quantity, it is not said

how large it is; consequently its conception is not the conception of a maximum. We cogitate in it merely its

relation to an arbitrarily assumed unit, in relation to which it is greater than any number. Now, just as the unit

which is taken is greater or smaller, the infinite will be greater or smaller; but the infinity, which consists

merely in the relation to this given unit, must remain always the same, although the absolute quantity of the

The true (transcendental) conception of infinity is: that the successive synthesis of unity in the measurement

of a given quantum can never be completed.* Hence it follows, without possibility of mistake, that an eternity

of actual successive states up to a given (the present) moment cannot have elapsed, and that the world must

*The quantum in this sense contains a congeries of given units, which is greater than any number and this is

In regard to the second part of the thesis, the difficulty as to an infinite and yet elapsed series disappears; for

the manifold of a world infinite in extension is contemporaneously given. But, in order to cogitate the total of

this manifold, as we cannot have the aid of limits constituting by themselves this total in intuition, we are

obliged to give some account of our conception, which in this case cannot proceed from the whole to the

determined quantity of the parts, but must demonstrate the possibility of a whole by means of a successive

synthesis of the parts. But as this synthesis must constitute a series that cannot be completed, it is impossible

for us to cogitate prior to it, and consequently not by means of it, a totality. For the conception of totality

itself is in the present case the representation of a completed synthesis of the parts; and this completion, and

The proof in favour of the infinity of the cosmical succession and the cosmical content is based upon the

consideration that, in the opposite case, a void time and a void space must constitute the limits of the world.

Now I am not unaware, that there are some ways of escaping this conclusion. It may, for example, be alleged,

that a limit to the world, as regards both space and time, is quite possible, without at the same time holding

the existence of an absolute time before the beginning of the world, or an absolute space extending beyond

the actual world which is impossible. I am quite well satisfied with the latter part of this opinion of the

philosophers of the Leibnitzian school. Space is merely the form of external intuition, but not a real object

which can itself be externally intuited; it is not a correlate of phenomena, it is the form of phenomena itself.

Space, therefore, cannot be regarded as absolutely and in itself something determinative of the existence of

things, because it is not itself an object, but only the form of possible objects. Consequently, things, as

phenomena, determine space; that is to say, they render it possible that, of all the possible predicates of space

(size and relation), certain may belong to reality. But we cannot affirm the converse, that space, as something

selfsubsistent, can determine real things in regard to size or shape, for it is in itself not a real thing. Space

(filled or void)* may therefore be limited by phenomena, but phenomena cannot be limited by an empty

space without them. This is true of time also. All this being granted, it is nevertheless indisputable, that we

must assume these two nonentities, void space without and void time before the world, if we assume the

*It is evident that what is meant here is, that empty space, in so far as it is limited by phenomena space, that

is, within the world does not at least contradict transcendental principles, and may therefore, as regards

For, as regards the subterfuge adopted by those who endeavour to evade the consequence that, if the world

is limited as to space and time, the infinite void must determine the existence of actual things in regard to

their dimensions it arises solely from the fact that instead of a sensuous world, an intelligible world of

which nothing is known is cogitated; instead of a real beginning (an existence, which is preceded by a

period in which nothing exists), an existence which presupposes no other condition than that of time; and,

instead of limits of extension, boundaries of the universe. But the question relates to the mundus

phaenomenon, and its quantity; and in this case we cannot make abstraction of the conditions of sensibility,

without doing away with the essential reality of this world itself. The world of sense, if it is limited, must

necessarily lie in the infinite void. If this, and with it space as the a priori condition of the possibility of

phenomena, is left out of view, the whole world of sense disappears. In our problem is this alone considered

as given. The mundus intelligibilis is nothing but the general conception of a world, in which abstraction has

been made of all conditions of intuition, and in relation to which no synthetical proposition either

Every composite substance in the world consists of simple parts; and there exists nothing that is not either

For, grant that composite substances do not consist of simple parts; in this case, if all combination or

composition were annihilated in thought, no composite part, and (as, by the supposition, there do not exist

simple parts) no simple part would exist. Consequently, no substance; consequently, nothing would exist.

Either, then, it is impossible to annihilate composition in thought; or, after such annihilation, there must

remain something that subsists without composition, that is, something that is simple. But in the former case

the composite could not itself consist of substances, because with substances composition is merely a

contingent relation, apart from which they must still exist as selfsubsistent beings. Now, as this case

contradicts the supposition, the second must contain the truth that the substantial composite in the world

It follows, as an immediate inference, that the things in the world are all, without exception, simple beings

that composition is merely an external condition pertaining to them and that, although we never can separate

and isolate the elementary substances from the state of composition, reason must cogitate these as the primary

subjects of all composition, and consequently, as prior thereto and as simple substances.

No composite thing in the world consists of simple parts; and there does not exist in the world any simple

Let it be supposed that a composite thing (as substance) consists of simple parts. Inasmuch as all external

relation, consequently all composition of substances, is possible only in space; the space, occupied by that

which is composite, must consist of the same number of parts as is contained in the composite. But space

does not consist of simple parts, but of spaces. Therefore, every part of the composite must occupy a space.

But the absolutely primary parts of what is composite are simple. It follows that what is simple occupies a

space. Now, as everything real that occupies a space, contains a manifold the parts of which are external to

each other, and is consequently composite and a real composite, not of accidents (for these cannot exist

external to each other apart from substance), but of substances it follows that the simple must be a

The second proposition of the antithesis that there exists in the world nothing that is simple is here

equivalent to the following: The existence of the absolutely simple cannot be demonstrated from any

experience or perception either external or internal; and the absolutely simple is a mere idea, the objective

reality of which cannot be demonstrated in any possible experience; it is consequently, in the exposition of

phenomena, without application and object. For, let us take for granted that an object may be found in

experience for this transcendental idea; the empirical intuition of such an object must then be recognized to

contain absolutely no manifold with its parts external to each other, and connected into unity. Now, as we

cannot reason from the nonconsciousness of such a manifold to the impossibility of its existence in the

intuition of an object, and as the proof of this impossibility is necessary for the establishment and proof of

absolute simplicity; it follows that this simplicity cannot be inferred from any perception whatever. As,

therefore, an absolutely simple object cannot be given in any experience, and the world of sense must be

considered as the sum total of all possible experiences: nothing simple exists in the world.

This second proposition in the antithesis has a more extended aim than the first. The first merely banishes the

simple from the intuition of the composite; while the second drives it entirely out of nature. Hence we were

unable to demonstrate it from the conception of a given object of external intuition (of the composite), but we

were obliged to prove it from the relation of a given object to a possible experience in general.

When I speak of a whole, which necessarily consists of simple parts, I understand thereby only a substantial

whole, as the true composite; that is to say, I understand that contingent unity of the manifold which is given

as perfectly isolated (at least in thought), placed in reciprocal connection, and thus constituted a unity. Space

ought not to be called a compositum but a totum, for its parts are possible in the whole, and not the whole by

means of the parts. It might perhaps be called a compositum ideale, but not a compositum reale. But this is of

no importance. As space is not a composite of substances (and not even of real accidents), if I abstract all

composition therein nothing, not even a point, remains; for a point is possible only as the limit of a space

consequently of a composite. Space and time, therefore, do not consist of simple parts. That which belongs

only to the condition or state of a substance, even although it possesses a quantity (motion or change, for

example), likewise does not consist of simple parts. That is to say, a certain degree of change does not

originate from the addition of many simple changes. Our inference of the simple from the composite is valid

only of selfsubsisting things. But the accidents of a state are not selfsubsistent. The proof, then, for the

necessity of the simple, as the component part of all that is substantial and composite, may prove a failure,

and the whole case of this thesis be lost, if we carry the proposition too far, and wish to make it valid of

everything that is composite without distinction as indeed has really now and then happened. Besides, I am

here speaking only of the simple, in so far as it is necessarily given in the composite the latter being capable

of solution into the former as its component parts. The proper signification of the word monas (as employed

by Leibnitz) ought to relate to the simple, given immediately as simple substance (for example, in

consciousness), and not as an element of the composite. As an clement, the term atomus would be more

appropriate. And as I wish to prove the existence of simple substances, only in relation to, and as the

elements of, the composite, I might term the antithesis of the second Antinomy, transcendental Atomistic.

But as this word has long been employed to designate a particular theory of corporeal phenomena

(moleculae), and thus presupposes a basis of empirical conceptions, I prefer calling it the dialectical principle

Against the assertion of the infinite subdivisibility of matter whose ground of proof is purely mathematical,

objections have been alleged by the Monadists. These objections lay themselves open, at first sight, to

suspicion, from the fact that they do not recognize the clearest mathematical proofs as propositions relating to

the constitution of space, in so far as it is really the formal condition of the possibility of all matter, but regard

them merely as inferences from abstract but arbitrary conceptions, which cannot have any application to real

things. just as if it were possible to imagine another mode of intuition than that given in the primitive

intuition of space; and just as if its a priori determinations did not apply to everything, the existence of which

is possible, from the fact alone of its filling space. If we listen to them, we shall find ourselves required to

cogitate, in addition to the mathematical point, which is simple not, however, a part, but a mere limit of

space physical points, which are indeed likewise simple, but possess the peculiar property, as parts of space,

of filling it merely by their aggregation. I shall not repeat here the common and clear refutations of this

absurdity, which are to be found everywhere in numbers: every one knows that it is impossible to undermine

the evidence of mathematics by mere discursive conceptions; I shall only remark that, if in this case

philosophy endeavours to gain an advantage over mathematics by sophistical artifices, it is because it forgets

that the discussion relates solely to Phenomena and their conditions. It is not sufficient to find the conception

of the simple for the pure conception of the composite, but we must discover for the intuition of the

composite (matter), the intuition of the simple. Now this, according to the laws of sensibility, and

consequently in the case of objects of sense, is utterly impossible. In the case of a whole composed of

substances, which is cogitated solely by the pure understanding, it may be necessary to be in possession of

the simple before composition is possible. But this does not hold good of the Totum substantiale

phaenomenon, which, as an empirical intuition in space, possesses the necessary property of containing no

simple part, for the very reason that no part of space is simple. Meanwhile, the Monadists have been subtle

enough to escape from this difficulty, by presupposing intuition and the dynamical relation of substances as

the condition of the possibility of space, instead of regarding space as the condition of the possibility of the

objects of external intuition, that is, of bodies. Now we have a conception of bodies only as phenomena, and,

as such, they necessarily presuppose space as the condition of all external phenomena. The evasion is

therefore in vain; as, indeed, we have sufficiently shown in our Aesthetic. If bodies were things in

The second dialectical assertion possesses the peculiarity of having opposed to it a dogmatical proposition,

which, among all such sophistical statements, is the only one that undertakes to prove in the case of an object

of experience, that which is properly a transcendental idea the absolute simplicity of substance. The

proposition is that the object of the internal sense, the thinking Ego, is an absolute simple substance. Without

at present entering upon this subject as it has been considered at length in a former chapter I shall merely

remark that, if something is cogitated merely as an object, without the addition of any synthetical

determination of its intuition as happens in the case of the bare representation, I it is certain that no

manifold and no composition can be perceived in such a representation. As, moreover, the predicates

whereby I cogitate this object are merely intuitions of the internal sense, there cannot be discovered in them

anything to prove the existence of a manifold whose parts are external to each other, and, consequently,

nothing to prove the existence of real composition. Consciousness, therefore, is so constituted that, inasmuch

as the thinking subject is at the same time its own object, it cannot divide itself although it can divide its

inhering determinations. For every object in relation to itself is absolute unity. Nevertheless, if the subject is

regarded externally, as an object of intuition, it must, in its character of phenomenon, possess the property of

composition. And it must always be regarded in this manner, if we wish to know whether there is or is not

Causality according to the laws of nature, is not the only causality operating to originate the phenomena of

the world. A causality of freedom is also necessary to account fully for these phenomena.

Let it be supposed, that there is no other kind of causality than that according to the laws of nature.

Consequently, everything that happens presupposes a previous condition, which it follows with absolute

certainty, in conformity with a rule. But this previous condition must itself be something that has happened

(that has arisen in time, as it did not exist before), for, if it has always been in existence, its consequence or

effect would not thus originate for the first time, but would likewise have always existed. The causality,

therefore, of a cause, whereby something happens, is itself a thing that has happened. Now this again

presupposes, in conformity with the law of nature, a previous condition and its causality, and this another

anterior to the former, and so on. If, then, everything happens solely in accordance with the laws of nature,

there cannot be any real first beginning of things, but only a subaltern or comparative beginning. There

cannot, therefore, be a completeness of series on the side of the causes which originate the one from the

other. But the law of nature is that nothing can happen without a sufficient a priori determined cause. The

proposition therefore if all causality is possible only in accordance with the laws of nature is, when stated

in this unlimited and general manner, selfcontradictory. It follows that this cannot be the only kind of

From what has been said, it follows that a causality must be admitted, by means of which something happens,

without its cause being determined according to necessary laws by some other cause preceding. That is to

say, there must exist an absolute spontaneity of cause, which of itself originates a series of phenomena which

proceeds according to natural laws consequently transcendental freedom, without which even in the course

There is no such thing as freedom, but everything in the world happens solely according to the laws of nature.

Granted, that there does exist freedom in the transcendental sense, as a peculiar kind of causality, operating to

produce events in the world a faculty, that is to say, of originating a state, and consequently a series of

consequences from that state. In this case, not only the series originated by this spontaneity, but the

determination of this spontaneity itself to the production of the series, that is to say, the causality itself must

have an absolute commencement, such that nothing can precede to determine this action according to

unvarying laws. But every beginning of action presupposes in the acting cause a state of inaction; and a

dynamically primal beginning of action presupposes a state, which has no connection as regards causality

with the preceding state of the cause which does not, that is, in any wise result from it. Transcendental

freedom is therefore opposed to the natural law of cause and effect, and such a conjunction of successive

states in effective causes is destructive of the possibility of unity in experience and for that reason not to be

We have, therefore, nothing but nature to which we must look for connection and order in cosmical events.

Freedom independence of the laws of nature is certainly a deliverance from restraint, but it is also a

relinquishing of the guidance of law and rule. For it cannot be alleged that, instead of the laws of nature, laws

of freedom may be introduced into the causality of the course of nature. For, if freedom were determined

according to laws, it would be no longer freedom, but merely nature. Nature, therefore, and transcendental

freedom are distinguishable as conformity to law and lawlessness. The former imposes upon understanding

the difficulty of seeking the origin of events ever higher and higher in the series of causes, inasmuch as

causality is always conditioned thereby; while it compensates this labour by the guarantee of a unity complete

and in conformity with law. The latter, on the contrary, holds out to the understanding the promise of a point

of rest in the chain of causes, by conducting it to an unconditioned causality, which professes to have the

power of spontaneous origination, but which, in its own utter blindness, deprives it of the guidance of rules,

The transcendental idea of freedom is far from constituting the entire content of the psychological conception

so termed, which is for the most part empirical. It merely presents us with the conception of spontaneity of

action, as the proper ground for imputing freedom to the cause of a certain class of objects. It is, however, the

true stumblingstone to philosophy, which meets with unconquerable difficulties in the way of its admitting

this kind of unconditioned causality. That element in the question of the freedom of the will, which bas for so

long a time placed speculative reason in such perplexity, is properly only transcendental, and concerns the

question, whether there must be held to exist a faculty of spontaneous origination of a series of successive

things or states. How such a faculty is possible is not a necessary inquiry; for in the case of natural causality

itself, we are obliged to content ourselves with the a priori knowledge that such a causality must be

presupposed, although we are quite incapable of comprehending how the being of one thing is possible

through the being of another, but must for this information look entirely to experience. Now we have

demonstrated this necessity of a free first beginning of a series of phenomena, only in so far as it is required

for the comprehension of an origin of the world, all following states being regarded as a succession according

to laws of nature alone. But, as there has thus been proved the existence of a faculty which can of itself

originate a series in time although we are unable to explain how it can exist we feel ourselves authorized to

admit, even in the midst of the natural course of events, a beginning, as regards causality, of different

successions of phenomena, and at the same time to attribute to all substances a faculty of free action. But we

ought in this case not to allow ourselves to fall into a common misunderstanding, and to suppose that,

because a successive series in the world can only have a comparatively first beginning another state or

condition of things always preceding an absolutely first beginning of a series in the course of nature is

impossible. For we are not speaking here of an absolutely first beginning in relation to time, but as regards

causality alone. When, for example, I, completely of my own free will, and independently of the necessarily

determinative influence of natural causes, rise from my chair, there commences with this event, including its

material consequences in infinitum, an absolutely new series; although, in relation to time, this event is

merely the continuation of a preceding series. For this resolution and act of mine do not form part of the

succession of effects in nature, and are not mere continuations of it; on the contrary, the determining causes

of nature cease to operate in reference to this event, which certainly succeeds the acts of nature, but does not

proceed from them. For these reasons, the action of a free agent must be termed, in regard to causality, if not

The justification of this need of reason to rest upon a free act as the first beginning of the series of natural

causes is evident from the fact, that all philosophers of antiquity (with the exception of the Epicurean school)

felt themselves obliged, when constructing a theory of the motions of the universe, to accept a prime mover,

that is, a freely acting cause, which spontaneously and prior to all other causes evolved this series of states.

They always felt the need of going beyond mere nature, for the purpose of making a first beginning

The assertor of the allsufficiency of nature in regard to causality (transcendental Physiocracy), in opposition

to the doctrine of freedom, would defend his view of the question somewhat in the following manner. He

would say, in answer to the sophistical arguments of the opposite party: If you do not accept a mathematical

first, in relation to time, you have no need to seek a dynamical first, in regard to causality. Who compelled

you to imagine an absolutely primal condition of the world, and therewith an absolute beginning of the

gradually progressing successions of phenomena and, as some foundation for this fancy of yours, to set

bounds to unlimited nature? Inasmuch as the substances in the world have always existed at least the unity

of experience renders such a supposition quite necessary there is no difficulty in believing also, that the

changes in the conditions of these substances have always existed; and, consequently, that a first beginning,

mathematical or dynamical, is by no means required. The possibility of such an infinite derivation, without

any initial member from which all the others result, is certainly quite incomprehensible. But, if you are rash

enough to deny the enigmatical secrets of nature for this reason, you will find yourselves obliged to deny also

the existence of many fundamental properties of natural objects (such as fundamental forces), which you can

just as little comprehend; and even the possibility of so simple a conception as that of change must present to

you insuperable difficulties. For if experience did not teach you that it was real, you never could conceive a

But if the existence of a transcendental faculty of freedom is granted a faculty of originating changes in the

world this faculty must at least exist out of and apart from the world; although it is certainly a bold

assumption, that, over and above the complete content of all possible intuitions, there still exists an object

which cannot be presented in any possible perception. But, to attribute to substances in the world itself such a

faculty, is quite inadmissible; for, in this case; the connection of phenomena reciprocally determining and

determined according to general laws, which is termed nature, and along with it the criteria of empirical truth,

which enable us to distinguish experience from mere visionary dreaming, would almost entirely disappear. In

proximity with such a lawless faculty of freedom, a system of nature is hardly cogitable; for the laws of the

latter would be continually subject to the intrusive influences of the former, and the course of phenomena,

which would otherwise proceed regularly and uniformly, would become thereby confused and disconnected.

There exists either in, or in connection with the world either as a part of it, or as the cause of itan

The world of sense, as the sum total of all phenomena, contains a series of changes. For, without such a

series, the mental representation of the series of time itself, as the condition of the possibility of the sensuous

world, could not be presented to us.* But every change stands under its condition, which precedes it in time

and renders it necessary. Now the existence of a given condition presupposes a complete series of conditions

up to the absolutely unconditioned, which alone is absolutely necessary. It follows that something that is

absolutely necessary must exist, if change exists as its consequence. But this necessary thing itself belongs to

the sensuous world. For suppose it to exist out of and apart from it, the series of cosmical changes would

receive from it a beginning, and yet this necessary cause would not itself belong to the world of sense. But

this is impossible. For, as the beginning of a series in time is determined only by that which precedes it in

time, the supreme condition of the beginning of a series of changes must exist in the time in which this series

itself did not exist; for a beginning supposes a time preceding, in which the thing that begins to be was not in

existence. The causality of the necessary cause of changes, and consequently the cause itself, must for these

reasons belong to time and to phenomena, time being possible only as the form of phenomena.

Consequently, it cannot be cogitated as separated from the world of sense the sum total of all phenomena.

There is, therefore, contained in the world, something that is absolutely necessary whether it be the whole

*Objectively, time, as the formal condition of the possibility of change, precedes all changes; but

subjectively, and in consciousness, the representation of time, like every other, is given solely by occasion of

An absolutely necessary being does not exist, either in the world, or out of it as its cause.

Grant that either the world itself is necessary, or that there is contained in it a necessary existence. Two cases

are possible. First, there must either be in the series of cosmical changes a beginning, which is

unconditionally necessary, and therefore uncaused which is at variance with the dynamical law of the

determination of all phenomena in time; or, secondly, the series itself is without beginning, and, although

contingent and conditioned in all its parts, is nevertheless absolutely necessary and unconditioned as a

whole which is selfcontradictory. For the existence of an aggregate cannot be necessary, if no single part

Grant, on the other band, that an absolutely necessary cause exists out of and apart from the world. This

cause, as the highest member in the series of the causes of cosmical changes, must originate or begin* the

existence of the latter and their series. In this case it must also begin to act, and its causality would therefore

belong to time, and consequently to the sum total of phenomena, that is, to the world. It follows that the cause

cannot be out of the world; which is contradictory to the hypothesis. Therefore, neither in the world, nor out

of it (but in causal connection with it), does there exist any absolutely necessary being.

*The word begin is taken in two senses. The first is active the cause being regarded as beginning a series of

conditions as its effect (infit). The second is passive the causality in the cause itself beginning to operate

To demonstrate the existence of a necessary being, I cannot be permitted in this place to employ any other

than the cosmological argument, which ascends from the conditioned in phenomena to the unconditioned in

conception the unconditioned being considered the necessary condition of the absolute totality of the series.

The proof, from the mere idea of a supreme being, belongs to another principle of reason and requires

The pure cosmological proof demonstrates the existence of a necessary being, but at the same time leaves it

quite unsettled, whether this being is the world itself, or quite distinct from it. To establish the truth of the

latter view, principles are requisite, which are not cosmological and do not proceed in the series of

phenomena. We should require to introduce into our proof conceptions of contingent beings regarded

merely as objects of the understanding, and also a principle which enables us to connect these, by means of

mere conceptions, with a necessary being. But the proper place for all such arguments is a transcendent

But, if we begin our proof cosmologically, by laying at the foundation of it the series of phenomena, and the

regress in it according to empirical laws of causality, we are not at liberty to break off from this mode of

demonstration and to pass over to something which is not itself a member of the series. The condition must

be taken in exactly the same signification as the relation of the conditioned to its condition in the series has

been taken, for the series must conduct us in an unbroken regress to this supreme condition. But if this

relation is sensuous, and belongs to the possible empirical employment of understanding, the supreme

condition or cause must close the regressive series according to the laws of sensibility and consequently, must

belong to the series of time. It follows that this necessary existence must be regarded as the highest member

Certain philosophers have, nevertheless, allowed themselves the liberty of making such a saltus (metabasis

eis allo gonos). From the changes in the world they have concluded their empirical contingency, that is, their

dependence on empiricallydetermined causes, and they thus admitted an ascending series of empirical

conditions: and in this they are quite right. But as they could not find in this series any primal beginning or

any highest member, they passed suddenly from the empirical conception of contingency to the pure

category, which presents us with a series not sensuous, but intellectual whose completeness does certainly

rest upon the existence of an absolutely necessary cause. Nay, more, this intellectual series is not tied to any

sensuous conditions; and is therefore free from the condition of time, which requires it spontaneously to

begin its causality in time. But such a procedure is perfectly inadmissible, as will be made plain from what

In the pure sense of the categories, that is contingent the contradictory opposite of which is possible. Now we

cannot reason from empirical contingency to intellectual. The opposite of that which is changed the opposite

of its state is actual at another time, and is therefore possible. Consequently, it is not the contradictory

opposite of the former state. To be that, it is necessary that, in the same time in which the preceding state

existed, its opposite could have existed in its place; but such a cognition is not given us in the mere

phenomenon of change. A body that was in motion = A, comes into a state of rest = nonA. Now it cannot be

concluded from the fact that a state opposite to the state A follows it, that the contradictory opposite of A is

possible; and that A is therefore contingent. To prove this, we should require to know that the state of rest

could have existed in the very same time in which the motion took place. Now we know nothing more than

that the state of rest was actual in the time that followed the state of motion; consequently, that it was also

possible. But motion at one time, and rest at another time, are not contradictorily opposed to each other. It

follows from what has been said that the succession of opposite determinations, that is, change, does not

demonstrate the fact of contingency as represented in the conceptions of the pure understanding; and that it

cannot, therefore, conduct us to the fact of the existence of a necessary being. Change proves merely

empirical contingency, that is to say, that the new state could not have existed without a cause, which belongs

to the preceding time. This cause even although it is regarded as absolutely necessary must be presented to

The difficulties which meet us, in our attempt to rise through the series of phenomena to the existence of an

absolutely necessary supreme cause, must not originate from our inability to establish the truth of our mere

conceptions of the necessary existence of a thing. That is to say, our objections not be ontological, but must

be directed against the causal connection with a series of phenomena of a condition which is itself

unconditioned. In one word, they must be cosmological and relate to empirical laws. We must show that the

regress in the series of causes (in the world of sense) cannot conclude with an empirically unconditioned

condition, and that the cosmological argument from the contingency of the cosmical state a contingency

alleged to arise from change does not justify us in accepting a first cause, that is, a prime originator of the

The reader will observe in this antinomy a very remarkable contrast. The very same grounds of proof which

established in the thesis the existence of a supreme being, demonstrated in the antithesis and with equal

strictness the nonexistence of such a being. We found, first, that a necessary being exists, because the

whole time past contains the series of all conditions, and with it, therefore, the unconditioned (the necessary);

secondly, that there does not exist any necessary being, for the same reason, that the whole time past contains

the series of all conditions which are themselves, therefore, in the aggregate, conditioned. The cause of this

seeming incongruity is as follows. We attend, in the first argument, solely to the absolute totality of the series

of conditions, the one of which determines the other in time, and thus arrive at a necessary unconditioned. In

the second, we consider, on the contrary, the contingency of everything that is determined in the series of

time for every event is preceded by a time, in which the condition itself must be determined as conditioned

and thus everything that is unconditioned or absolutely necessary disappears. In both, the mode of proof is

quite in accordance with the common procedure of human reason, which often falls into discord with itself,

from considering an object from two different points of view. Herr von Mairan regarded the controversy

between two celebrated astronomers, which arose from a similar difficulty as to the choice of a proper

standpoint, as a phenomenon of sufficient importance to warrant a separate treatise on the subject. The one

concluded: the moon revolves on its own axis, because it constantly presents the same side to the earth; the

other declared that the moon does not revolve on its own axis, for the same reason. Both conclusions were

perfectly correct, according to the point of view from which the motions of the moon were considered.

We have thus completely before us the dialectical procedure of the cosmological ideas. No possible

experience can present us with an object adequate to them in extent. Nay, more, reason itself cannot cogitate

them as according with the general laws of experience. And yet they are not arbitrary fictions of thought. On

the contrary, reason, in its uninterrupted progress in the empirical synthesis, is necessarily conducted to them,

when it endeavours to free from all conditions and to comprehend in its unconditioned totality that which can

only be determined conditionally in accordance with the laws of experience. These dialectical propositions

are so many attempts to solve four natural and unavoidable problems of reason. There are neither more, nor

can there be less, than this number, because there are no other series of synthetical hypotheses, limiting a

The brilliant claims of reason striving to extend its dominion beyond the limits of experience, have been

represented above only in dry formulae, which contain merely the grounds of its pretensions. They have,

besides, in conformity with the character of a transcendental philosophy, been freed from every empirical

element; although the full splendour of the promises they hold out, and the anticipations they excite,

manifests itself only when in connection with empirical cognitions. In the application of them, however, and

in the advancing enlargement of the employment of reason, while struggling to rise from the region of

experience and to soar to those sublime ideas, philosophy discovers a value and a dignity, which, if it could

but make good its assertions, would raise it far above all other departments of human knowledge professing,

as it does, to present a sure foundation for our highest hopes and the ultimate aims of all the exertions of

reason. The questions: whether the world has a beginning and a limit to its extension in space; whether there

exists anywhere, or perhaps, in my own thinking Self, an indivisible and indestructible unity or whether

nothing but what is divisible and transitory exists; whether I am a free agent, or, like other beings, am bound

in the chains of nature and fate; whether, finally, there is a supreme cause of the world, or all our thought and

speculation must end with nature and the order of external things are questions for the solution of which the

mathematician would willingly exchange his whole science; for in it there is no satisfaction for the highest

aspirations and most ardent desires of humanity. Nay, it may even be said that the true value of mathematics

that pride of human reason consists in this: that she guides reason to the knowledge of nature in her greater

as well as in her less manifestations in her beautiful order and regularity guides her, moreover, to an

insight into the wonderful unity of the moving forces in the operations of nature, far beyond the expectations

of a philosophy building only on experience; and that she thus encourages philosophy to extend the province

of reason beyond all experience, and at the same time provides it with the most excellent materials for

supporting its investigations, in so far as their nature admits, by adequate and accordant intuitions.

Unfortunately for speculation but perhaps fortunately for the practical interests of humanity reason, in the

midst of her highest anticipations, finds herself hemmed in by a press of opposite and contradictory

conclusions, from which neither her honour nor her safety will permit her to draw back. Nor can she regard

these conflicting trains of reasoning with indifference as mere passages at arms, still less can she command

peace; for in the subject of the conflict she has a deep interest. There is no other course left open to her than

to reflect with herself upon the origin of this disunion in reason whether it may not arise from a mere

misunderstanding. After such an inquiry, arrogant claims would have to be given up on both sides; but the

sovereignty of reason over understanding and sense would be based upon a sure foundation.

We shall at present defer this radical inquiry and, in the meantime, consider for a little what side in the

controversy we should most willingly take, if we were obliged to become partisans at all. As, in this case, we

leave out of sight altogether the logical criterion of truth, and merely consult our own interest in reference to

the question, these considerations, although inadequate to settle the question of right in either party, will

enable us to comprehend how those who have taken part in the struggle, adopt the one view rather than the

other no special insight into the subject, however, having influenced their choice. They will, at the same

time, explain to us many other things by the way for example, the fiery zeal on the one side and the cold

maintenance of their cause on the other; why the one party has met with the warmest approbations, and the

There is one thing, however, that determines the proper point of view, from which alone this preliminary

inquiry can be instituted and carried on with the proper completeness and that is the comparison of the

principles from which both sides, thesis and antithesis, proceed. My readers would remark in the propositions

of the antithesis a complete uniformity in the mode of thought and a perfect unity of principle. Its principle

was that of pure empiricism, not only in the explication of the phenomena in the world, but also in the

solution of the transcendental ideas, even of that of the universe itself. The affirmations of the thesis, on the

contrary, were based, in addition to the empirical mode of explanation employed in the series of phenomena,

on intellectual propositions; and its principles were in so far not simple. I shall term the thesis, in view of its

On the side of Dogmatism, or of the thesis, therefore, in the determination of the cosmological ideas, we find:

1. A practical interest, which must be very dear to every rightthinking man. That the word has a beginning

that the nature of my thinking self is simple, and therefore indestructible that I am a free agent, and raised

above the compulsion of nature and her laws and, finally, that the entire order of things, which form the

world, is dependent upon a Supreme Being, from whom the whole receives unity and connection these are

so many foundationstones of morality and religion. The antithesis deprives us of all these supports or, at

2. A speculative interest of reason manifests itself on this side. For, if we take the transcendental ideas and

employ them in the manner which the thesis directs, we can exhibit completely a priori the entire chain of

conditions, and understand the derivation of the conditioned beginning from the unconditioned. This the

antithesis does not do; and for this reason does not meet with so welcome a reception. For it can give no

answer to our question respecting the conditions of its synthesis except such as must be supplemented by

another question, and so on to infinity. According to it, we must rise from a given beginning to one still

higher; every part conducts us to a still smaller one; every event is preceded by another event which is its

cause; and the conditions of existence rest always upon other and still higher conditions, and find neither end

3. This side has also the advantage of popularity; and this constitutes no small part of its claim to favour. The

common understanding does not find the least difficulty in the idea of the unconditioned beginning of all

synthesis accustomed, as it is, rather to follow our consequences than to seek for a proper basis for

cognition. In the conception of an absolute first, moreover the possibility of which it does not inquire into

it is highly gratified to find a firmlyestablished point of departure for its attempts at theory; while in the

restless and continuous ascent from the conditioned to the condition, always with one foot in the air, it can

On the side of the antithesis, or Empiricism, in the determination of the cosmological ideas:

1. We cannot discover any such practical interest arising from pure principles of reason as morality and

religion present. On the contrary, pure empiricism seems to empty them of all their power and influence. If

there does not exist a Supreme Being distinct from the world if the world is without beginning,

consequently without a Creator if our wills are not free, and the soul is divisible and subject to corruption

just like matter the ideas and principles of morality lose all validity and fall with the transcendental ideas

2. But empiricism, in compensation, holds out to reason, in its speculative interests, certain important

advantages, far exceeding any that the dogmatist can promise us. For, when employed by the empiricist,

understanding is always upon its proper ground of investigation the field of possible experience, the laws of

which it can explore, and thus extend its cognition securely and with clear intelligence without being stopped

by limits in any direction. Here can it and ought it to find and present to intuition its proper object not only

in itself, but in all its relations; or, if it employ conceptions, upon this ground it can always present the

corresponding images in clear and unmistakable intuitions. It is quite unnecessary for it to renounce the

guidance of nature, to attach itself to ideas, the objects of which it cannot know; because, as mere intellectual

entities, they cannot be presented in any intuition. On the contrary, it is not even permitted to abandon its

proper occupation, under the pretence that it has been brought to a conclusion (for it never can be), and to

pass into the region of idealizing reason and transcendent conceptions, which it is not required to observe and

explore the laws of nature, but merely to think and to imagine secure from being contradicted by facts,

because they have not been called as witnesses, but passed by, or perhaps subordinated to the socalled

Hence the empiricist will never allow himself to accept any epoch of nature for the first the absolutely

primal state; he will not believe that there can be limits to his outlook into her wide domains, nor pass from

the objects of nature, which he can satisfactorily explain by means of observation and mathematical thought

which he can determine synthetically in intuition, to those which neither sense nor imagination can ever

present in concreto; he will not concede the existence of a faculty in nature, operating independently of the

laws of nature a concession which would introduce uncertainty into the procedure of the understanding,

which is guided by necessary laws to the observation of phenomena; nor, finally, will he permit himself to

seek a cause beyond nature, inasmuch as we know nothing but it, and from it alone receive an objective basis

In truth, if the empirical philosopher had no other purpose in the establishment of his antithesis than to check

the presumption of a reason which mistakes its true destination, which boasts of its insight and its knowledge,

just where all insight and knowledge cease to exist, and regards that which is valid only in relation to a

practical interest, as an advancement of the speculative interests of the mind (in order, when it is convenient

for itself, to break the thread of our physical investigations, and, under pretence of extending our cognition,

connect them with transcendental ideas, by means of which we really know only that we know nothing) if, I

say, the empiricist rested satisfied with this benefit, the principle advanced by him would be a maxim

recommending moderation in the pretensions of reason and modesty in its affirmations, and at the same time

would direct us to the right mode of extending the province of the understanding, by the help of the only true

teacher, experience. In obedience to this advice, intellectual hypotheses and faith would not be called in aid

of our practical interests; nor should we introduce them under the pompous titles of science and insight. For

speculative cognition cannot find an objective basis any other where than in experience; and, when we

overstep its limits our synthesis, which requires ever new cognitions independent of experience, has no

But if as often happens empiricism, in relation to ideas, becomes itself dogmatic and boldly denies that

which is above the sphere of its phenomenal cognition, it falls itself into the error of intemperance an error

which is here all the more reprehensible, as thereby the practical interest of reason receives an irreparable

*It is, however, still a matter of doubt whether Epicurus ever propounded these principles as directions for the

objective employment of the understanding. If, indeed, they were nothing more than maxims for the

speculative exercise of reason, he gives evidence therein a more genuine philosophic spirit than any of the

philosophers of antiquity. That, in the explanation of phenomena, we must proceed as if the field of inquiry

had neither limits in space nor commencement in time; that we must be satisfied with the teaching of

experience in reference to the material of which the world is posed; that we must not look for any other mode

of the origination of events than that which is determined by the unalterable laws of nature; and finally, that

we not employ the hypothesis of a cause distinct from the world to account for a phenomenon or for the

world itself are principles for the extension of speculative philosophy, and the discovery of the true sources

of the principles of morals, which, however little conformed to in the present day, are undoubtedly correct. At

the same time, any one desirous of ignoring, in mere speculation, these dogmatical propositions, need not for

Both Epicurus and Plato assert more in their systems than they know. The former encourages and advances

science although to the prejudice of the practical; the latter presents us with excellent principles for the

investigation of the practical, but, in relation to everything regarding which we can attain to speculative

cognition, permits reason to append idealistic explanations of natural phenomena, to the great injury of

3. In regard to the third motive for the preliminary choice of a party in this war of assertions, it seems very

extraordinary that empiricism should be utterly unpopular. We should be inclined to believe that the common

understanding would receive it with pleasure promising as it does to satisfy it without passing the bounds of

experience and its connected order; while transcendental dogmatism obliges it to rise to conceptions which

far surpass the intelligence and ability of the most practised thinkers. But in this, in truth, is to be found its

real motive. For the common understanding thus finds itself in a situation where not even the most learned

can have the advantage of it. If it understands little or nothing about these transcendental conceptions, no one

can boast of understanding any more; and although it may not express itself in so scholastically correct a

manner as others, it can busy itself with reasoning and arguments without end, wandering among mere ideas,

about which one can always be very eloquent, because we know nothing about them; while, in the

observation and investigation of nature, it would be forced to remain dumb and to confess its utter ignorance.

Thus indolence and vanity form of themselves strong recommendations of these principles. Besides, although

it is a hard thing for a philosopher to assume a principle, of which he can give to himself no reasonable

account, and still more to employ conceptions, the objective reality of which cannot be established, nothing is

more usual with the common understanding. It wants something which will allow it to go to work with

confidence. The difficulty of even comprehending a supposition does not disquiet it, because not knowing

what comprehending means it never even thinks of the supposition it may be adopting as a principle; and

regards as known that with which it has become familiar from constant use. And, at last, all speculative

interests disappear before the practical interests which it holds dear; and it fancies that it understands and

knows what its necessities and hopes incite it to assume or to believe. Thus the empiricism of

transcendentally idealizing reason is robbed of all popularity; and, however prejudicial it may be to the

highest practical principles, there is no fear that it will ever pass the limits of the schools, or acquire any

Human reason is by nature architectonic. That is to say, it regards all cognitions as parts of a possible system,

and hence accepts only such principles as at least do not incapacitate a cognition to which we may have

attained from being placed along with others in a general system. But the propositions of the antithesis are of

a character which renders the completion of an edifice of cognitions impossible. According to these, beyond

one state or epoch of the world there is always to be found one more ancient; in every part always other parts

themselves divisible; preceding every event another, the origin of which must itself be sought still higher; and

everything in existence is conditioned, and still not dependent on an unconditioned and primal existence. As,

therefore, the antithesis will not concede the existence of a first beginning which might be available as a

foundation, a complete edifice of cognition, in the presence of such hypothesis, is utterly impossible. Thus

the architectonic interest of reason, which requires a unity not empirical, but a priori and rational forms a

But if any one could free himself entirely from all considerations of interest, and weigh without partiality the

assertions of reason, attending only to their content, irrespective of the consequences which follow from

them; such a person, on the supposition that he knew no other way out of the confusion than to settle the truth

of one or other of the conflicting doctrines, would live in a state of continual hesitation. Today, he would feel

convinced that the human will is free; tomorrow, considering the indissoluble chain of nature, he would

look on freedom as a mere illusion and declare nature to be allinall. But, if he were called to action, the

play of the merely speculative reason would disappear like the shapes of a dream, and practical interest would

dictate his choice of principles. But, as it well befits a reflective and inquiring being to devote certain periods

of time to the examination of its own reason to divest itself of all partiality, and frankly to communicate its

observations for the judgement and opinion of others; so no one can be blamed for, much less prevented

from, placing both parties on their trial, with permission to end themselves, free from intimidation, before

intimidation, before a sworn jury of equal condition with themselves the condition of weak and fallible men.

To avow an ability to solve all problems and to answer all questions would be a profession certain to convict

any philosopher of extravagant boasting and selfconceit, and at once to destroy the confidence that might

otherwise have been reposed in him. There are, however, sciences so constituted that every question arising

within their sphere must necessarily be capable of receiving an answer from the knowledge already

possessed, for the answer must be received from the same sources whence the question arose. In such

sciences it is not allowable to excuse ourselves on the plea of necessary and unavoidable ignorance; a

solution is absolutely requisite. The rule of right and wrong must help us to the knowledge of what is right or

wrong in all possible cases; otherwise, the idea of obligation or duty would be utterly null, for we cannot have

SECTION IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its Transcendental Problems. 163

any obligation to that which we cannot know. On the other hand, in our investigations of the phenomena of

nature, much must remain uncertain, and many questions continue insoluble; because what we know of

nature is far from being sufficient to explain all the phenomena that are presented to our observation. Now the

question is: "Whether there is in transcendental philosophy any question, relating to an object presented to

pure reason, which is unanswerable by this reason; and whether we must regard the subject of the question as

quite uncertain, so far as our knowledge extends, and must give it a place among those subjects, of which we

have just so much conception as is sufficient to enable us to raise a question faculty or materials failing us,

Now I maintain that, among all speculative cognition, the peculiarity of transcendental philosophy is that

there is no question, relating to an object presented to pure reason, which is insoluble by this reason; and that

the profession of unavoidable ignorance the problem being alleged to be beyond the reach of our faculties

cannot free us from the obligation to present a complete and satisfactory answer. For the very conception

which enables us to raise the question must give us the power of answering it; inasmuch as the object, as in

But, in transcendental philosophy, it is only the cosmological questions to which we can demand a

satisfactory answer in relation to the constitution of their object; and the philosopher is not permitted to avail

himself of the pretext of necessary ignorance and impenetrable obscurity. These questions relate solely to the

cosmological ideas. For the object must be given in experience, and the question relates to the adequateness

of the object to an idea. If the object is transcendental and therefore itself unknown; if the question, for

example, is whether the object the something, the phenomenon of which (internal in ourselves) is thought

that is to say, the soul, is in itself a simple being; or whether there is a cause of all things, which is absolutely

necessary in such cases we are seeking for our idea an object, of which we may confess that it is unknown

to us, though we must not on that account assert that it is impossible.* The cosmological ideas alone posses

the peculiarity that we can presuppose the object of them and the empirical synthesis requisite for the

conception of that object to be given; and the question, which arises from these ideas, relates merely to the

progress of this synthesis, in so far as it must contain absolute totality which, however, is not empirical, as it

cannot be given in any experience. Now, as the question here is solely in regard to a thing as the object of a

possible experience and not as a thing in itself, the answer to the transcendental cosmological question need

not be sought out of the idea, for the question does not regard an object in itself. The question in relation to a

possible experience is not, "What can be given in an experience in concreto" but "what is contained in the

idea, to which the empirical synthesis must approximate." The question must therefore be capable of solution

from the idea alone. For the idea is a creation of reason itself, which therefore cannot disclaim the obligation

*The question, "What is the constitution of a transcendental object?" is unanswerable we are unable to say

what it is; but we can perceive that the question itself is nothing; because it does not relate to any object that

can be presented to us. For this reason, we must consider all the questions raised in transcendental

psychology as answerable and as really answered; for they relate to the transcendental subject of all internal

phenomena, which is not itself phenomenon and consequently not given as an object, in which, moreover,

none of the categories and it is to them that the question is properly directed find any conditions of its

application. Here, therefore, is a case where no answer is the only proper answer. For a question regarding the

constitution of a something which cannot be cogitated by any determined predicate, being completely beyond

It is not so extraordinary, as it at first sight appears, that a science should demand and expect satisfactory

answers to all the questions that may arise within its own sphere (questiones domesticae), although, up to a

certain time, these answers may not have been discovered. There are, in addition to transcendental

philosophy, only two pure sciences of reason; the one with a speculative, the other with a practical content

pure mathematics and pure ethics. Has any one ever heard it alleged that, from our complete and necessary

SECTION IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its Transcendental Problems. 164

ignorance of the conditions, it is uncertain what exact relation the diameter of a circle bears to the circle in

rational or irrational numbers? By the former the sum cannot be given exactly, by the latter only

approximately; and therefore we decide that the impossibility of a solution of the question is evident.

Lambert presented us with a demonstration of this. In the general principles of morals there can be nothing

uncertain, for the propositions are either utterly without meaning, or must originate solely in our rational

conceptions. On the other hand, there must be in physical science an infinite number of conjectures, which

can never become certainties; because the phenomena of nature are not given as objects dependent on our

conceptions. The key to the solution of such questions cannot, therefore, be found in our conceptions, or in

pure thought, but must lie without us and for that reason is in many cases not to be discovered; and

consequently a satisfactory explanation cannot be expected. The questions of transcendental analytic, which

relate to the deduction of our pure cognition, are not to be regarded as of the same kind as those mentioned

above; for we are not at present treating of the certainty of judgements in relation to the origin of our

We cannot, therefore, escape the responsibility of at least a critical solution of the questions of reason, by

complaints of the limited nature of our faculties, and the seemingly humble confession that it is beyond the

power of our reason to decide, whether the world has existed from all eternity or had a beginning whether it

is infinitely extended, or enclosed within certain limits whether anything in the world is simple, or whether

everything must be capable of infinite divisibility whether freedom can originate phenomena, or whether

everything is absolutely dependent on the laws and order of nature and, finally, whether there exists a being

that is completely unconditioned and necessary, or whether the existence of everything is conditioned and

consequently dependent on something external to itself, and therefore in its own nature contingent. For all

these questions relate to an object, which can be given nowhere else than in thought. This object is the

absolutely unconditioned totality of the synthesis of phenomena. If the conceptions in our minds do not assist

us to some certain result in regard to these problems, we must not defend ourselves on the plea that the object

itself remains hidden from and unknown to us. For no such thing or object can be given it is not to be found

out of the idea in our minds. We must seek the cause of our failure in our idea itself, which is an insoluble

problem and in regard to which we obstinately assume that there exists a real object corresponding and

adequate to it. A clear explanation of the dialectic which lies in our conception, will very soon enable us to

The pretext that we are unable to arrive at certainty in regard to these problems may be met with this

question, which requires at least a plain answer: "From what source do the ideas originate, the solution of

which involves you in such difficulties? Are you seeking for an explanation of certain phenomena; and do

you expect these ideas to give you the principles or the rules of this explanation?" Let it be granted, that all

nature was laid open before you; that nothing was hid from your senses and your consciousness. Still, you

could not cognize in concreto the object of your ideas in any experience. For what is demanded is not only

this full and complete intuition, but also a complete synthesis and the consciousness of its absolute totality;

and this is not possible by means of any empirical cognition. It follows that your question your idea is by

no means necessary for the explanation of any phenomenon; and the idea cannot have been in any sense

given by the object itself. For such an object can never be presented to us, because it cannot be given by any

possible experience. Whatever perceptions you may attain to, you are still surrounded by conditions in

space, or in time and you cannot discover anything unconditioned; nor can you decide whether this

unconditioned is to be placed in an absolute beginning of the synthesis, or in an absolute totality of the series

without beginning. A whole, in the empirical signification of the term, is always merely comparative. The

absolute whole of quantity (the universe), of division, of derivation, of the condition of existence, with the

question whether it is to be produced by finite or infinite synthesis, no possible experience can instruct us

concerning. You will not, for example, be able to explain the phenomena of a body in the least degree better,

whether you believe it to consist of simple, or of composite parts; for a simple phenomenon and just as little

an infinite series of composition can never be presented to your perception. Phenomena require and admit of

explanation, only in so far as the conditions of that explanation are given in perception; but the sum total of

SECTION IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its Transcendental Problems. 165

that which is given in phenomena, considered as an absolute whole, is itself a perception and we cannot

therefore seek for explanations of this whole beyond itself, in other perceptions. The explanation of this

Although, therefore, the solution of these problems is unattainable through experience, we must not permit

ourselves to say that it is uncertain how the object of our inquiries is constituted. For the object is in our own

mind and cannot be discovered in experience; and we have only to take care that our thoughts are consistent

with each other, and to avoid falling into the amphiboly of regarding our idea as a representation of an object

empirically given, and therefore to be cognized according to the laws of experience. A dogmatical solution is

therefore not only unsatisfactory but impossible. The critical solution, which may be a perfectly certain one,

does not consider the question objectively, but proceeds by inquiring into the basis of the cognition upon

We should be quite willing to desist from the demand of a dogmatical answer to our questions, if we

understood beforehand that, be the answer what it may, it would only serve to increase our ignorance, to

throw us from one incomprehensibility into another, from one obscurity into another still greater, and perhaps

lead us into irreconcilable contradictions. If a dogmatical affirmative or negative answer is demanded, is it at

all prudent to set aside the probable grounds of a solution which lie before us and to take into consideration

what advantage we shall gain, if the answer is to favour the one side or the other? If it happens that in both

cases the answer is mere nonsense, we have in this an irresistible summons to institute a critical investigation

of the question, for the purpose of discovering whether it is based on a groundless presupposition and relates

to an idea, the falsity of which would be more easily exposed in its application and consequences than in the

mere representation of its content. This is the great utility of the sceptical mode of treating the questions

addressed by pure reason to itself. By this method we easily rid ourselves of the confusions of dogmatism,

and establish in its place a temperate criticism, which, as a genuine cathartic, will successfully remove the

presumptuous notions of philosophy and their consequence the vain pretension to universal science.

If, then, I could understand the nature of a cosmological idea and perceive, before I entered on the discussion

of the subject at all, that, whatever side of the question regarding the unconditioned of the regressive

synthesis of phenomena it favoured it must either be too great or too small for every conception of the

understanding I would be able to comprehend how the idea, which relates to an object of experience an

experience which must be adequate to and in accordance with a possible conception of the understanding

must be completely void and without significance, inasmuch as its object is inadequate, consider it as we

may. And this is actually the case with all cosmological conceptions, which, for the reason above mentioned,

involve reason, so long as it remains attached to them, in an unavoidable antinomy. For suppose:

First, that the world has no beginning in this case it is too large for our conception; for this conception,

which consists in a successive regress, cannot overtake the whole eternity that has elapsed. Grant that it has a

beginning, it is then too small for the conception of the understanding. For, as a beginning presupposes a time

preceding, it cannot be unconditioned; and the law of the empirical employment of the understanding

imposes the necessity of looking for a higher condition of time; and the world is, therefore, evidently too

The same is the case with the double answer to the question regarding the extent, in space, of the world. For,

if it is infinite and unlimited, it must be too large for every possible empirical conception. If it is finite and

limited, we have a right to ask: "What determines these limits?" Void space is not a selfsubsistent correlate

of things, and cannot be a final condition and still less an empirical condition, forming a part of a possible

SECTION V. Sceptical Exposition of the Cosmological Problems presented in the four Transcendental Ideas. 166

experience. For how can we have any experience or perception of an absolute void? But the absolute totality

of the empirical synthesis requires that the unconditioned be an empirical conception. Consequently, a finite

Secondly, if every phenomenon (matter) in space consists of an infinite number of parts, the regress of the

division is always too great for our conception; and if the division of space must cease with some member of

the division (the simple), it is too small for the idea of the unconditioned. For the member at which we have

discontinued our division still admits a regress to many more parts contained in the object.

Thirdly, suppose that every event in the world happens in accordance with the laws of nature; the causality of

a cause must itself be an event and necessitates a regress to a still higher cause, and consequently the

unceasing prolongation of the series of conditions a parte priori. Operative nature is therefore too large for

If we admit the existence of spontaneously produced events, that is, of free agency, we are driven, in our

search for sufficient reasons, on an unavoidable law of nature and are compelled to appeal to the empirical

law of causality, and we find that any such totality of connection in our synthesis is too small for our

Fourthly, if we assume the existence of an absolutely necessary being whether it be the world or something

in the world, or the cause of the world we must place it in a time at an infinite distance from any given

moment; for, otherwise, it must be dependent on some other and higher existence. Such an existence is, in

this case, too large for our empirical conception, and unattainable by the continued regress of any synthesis.

But if we believe that everything in the world be it condition or conditioned is contingent; every given

existence is too small for our conception. For in this case we are compelled to seek for some other existence

We have said that in all these cases the cosmological idea is either too great or too small for the empirical

regress in a synthesis, and consequently for every possible conception of the understanding. Why did we not

express ourselves in a manner exactly the reverse of this and, instead of accusing the cosmological idea of

over stepping or of falling short of its true aim, possible experience, say that, in the first case, the empirical

conception is always too small for the idea, and in the second too great, and thus attach the blame of these

contradictions to the empirical regress? The reason is this. Possible experience can alone give reality to our

conceptions; without it a conception is merely an idea, without truth or relation to an object. Hence a possible

empirical conception must be the standard by which we are to judge whether an idea is anything more than an

idea and fiction of thought, or whether it relates to an object in the world. If we say of a thing that in relation

to some other thing it is too large or too small, the former is considered as existing for the sake of the latter,

and requiring to be adapted to it. Among the trivial subjects of discussion in the old schools of dialectics was

this question: "If a ball cannot pass through a hole, shall we say that the ball is too large or the hole too

small?" In this case it is indifferent what expression we employ; for we do not know which exists for the sake

of the other. On the other hand, we cannot say: "The man is too long for his coat"; but: "The coat is too short

We are thus led to the wellfounded suspicion that the cosmological ideas, and all the conflicting sophistical

assertions connected with them, are based upon a false and fictitious conception of the mode in which the

object of these ideas is presented to us; and this suspicion will probably direct us how to expose the illusion

SECTION V. Sceptical Exposition of the Cosmological Problems presented in the four Transcendental Ideas. 167

In the transcendental aesthetic we proved that everything intuited in space and time, all objects of a possible

experience, are nothing but phenomena, that is, mere representations; and that these, as presented to us as

extended bodies, or as series of changes have no selfsubsistent existence apart from human thought. This

doctrine I call Transcendental Idealism.* The realist in the transcendental sense regards these modifications

of our sensibility, these mere representations, as things subsisting in themselves.

*I have elsewhere termed this theory formal idealism, to distinguish it from material idealism, which doubts

or denies the existence of external things. To avoid ambiguity, it seems advisable in many cases to employ

It would be unjust to accuse us of holding the longdecried theory of empirical idealism, which, while

admitting the reality of space, denies, or at least doubts, the existence of bodies extended in it, and thus leaves

us without a sufficient criterion of reality and illusion. The supporters of this theory find no difficulty in

admitting the reality of the phenomena of the internal sense in time; nay, they go the length of maintaining

that this internal experience is of itself a sufficient proof of the real existence of its object as a thing in itself.

Transcendental idealism allows that the objects of external intuition as intuited in space, and all changes in

time as represented by the internal sense, are real. For, as space is the form of that intuition which we call

external, and, without objects in space, no empirical representation could be given us, we can and ought to

regard extended bodies in it as real. The case is the same with representations in time. But time and space,

with all phenomena therein, are not in themselves things. They are nothing but representations and cannot

exist out of and apart from the mind. Nay, the sensuous internal intuition of the mind (as the object of

consciousness), the determination of which is represented by the succession of different states in time, is not

the real, proper self, as it exists in itself not the transcendental subject but only a phenomenon, which is

presented to the sensibility of this, to us, unknown being. This internal phenomenon cannot be admitted to be

a selfsubsisting thing; for its condition is time, and time cannot be the condition of a thing in itself. But the

empirical truth of phenomena in space and time is guaranteed beyond the possibility of doubt, and

sufficiently distinguished from the illusion of dreams or fancy although both have a proper and thorough

connection in an experience according to empirical laws. The objects of experience then are not things in

themselves, but are given only in experience, and have no existence apart from and independently of

experience. That there may be inhabitants in the moon, although no one has ever observed them, must

certainly be admitted; but this assertion means only, that we may in the possible progress of experience

discover them at some future time. For that which stands in connection with a perception according to the

laws of the progress of experience is real. They are therefore really existent, if they stand in empirical

connection with my actual or real consciousness, although they are not in themselves real, that is, apart from

There is nothing actually given we can be conscious of nothing as real, except a perception and the

empirical progression from it to other possible perceptions. For phenomena, as mere representations, are real

only in perception; and perception is, in fact, nothing but the reality of an empirical representation, that is, a

phenomenon. To call a phenomenon a real thing prior to perception means either that we must meet with this

phenomenon in the progress of experience, or it means nothing at all. For I can say only of a thing in itself

that it exists without relation to the senses and experience. But we are speaking here merely of phenomena in

space and time, both of which are determinations of sensibility, and not of things in themselves. It follows

that phenomena are not things in themselves, but are mere representations, which if not given in us in

SECTION VI. Transcendental Idealism as the Key to the Solution of Pure Cosmological Dialectic. 168

The faculty of sensuous intuition is properly a receptivity a capacity of being affected in a certain manner by

representations, the relation of which to each other is a pure intuition of space and time the pure forms of

sensibility. These representations, in so far as they are connected and determinable in this relation (in space

and time) according to laws of the unity of experience, are called objects. The nonsensuous cause of these

representations is completely unknown to us and hence cannot be intuited as an object. For such an object

could not be represented either in space or in time; and without these conditions intuition or representation is

impossible. We may, at the same time, term the nonsensuous cause of phenomena the transcendental

object but merely as a mental correlate to sensibility, considered as a receptivity. To this transcendental

object we may attribute the whole connection and extent of our possible perceptions, and say that it is given

and exists in itself prior to all experience. But the phenomena, corresponding to it, are not given as things in

themselves, but in experience alone. For they are mere representations, receiving from perceptions alone

significance and relation to a real object, under the condition that this or that perception indicating an

object is in complete connection with all others in accordance with the rules of the unity of experience. Thus

we can say: "The things that really existed in past time are given in the transcendental object of experience."

But these are to me real objects, only in so far as I can represent to my own mind, that a regressive series of

possible perceptions following the indications of history, or the footsteps of cause and effect in accordance

with empirical laws that, in one word, the course of the world conducts us to an elapsed series of time as the

condition of the present time. This series in past time is represented as real, not in itself, but only in

connection with a possible experience. Thus, when I say that certain events occurred in past time, I merely

assert the possibility of prolonging the chain of experience, from the present perception, upwards to the

If I represent to myself all objects existing in all space and time, I do not thereby place these in space and

time prior to all experience; on the contrary, such a representation is nothing more than the notion of a

possible experience, in its absolute completeness. In experience alone are those objects, which are nothing

but representations, given. But, when I say they existed prior to my experience, this means only that I must

begin with the perception present to me and follow the track indicated until I discover them in some part or

region of experience. The cause of the empirical condition of this progression and consequently at what

member therein I must stop, and at what point in the regress I am to find this member is transcendental, and

hence necessarily incognizable. But with this we have not to do; our concern is only with the law of

progression in experience, in which objects, that is, phenomena, are given. It is a matter of indifference,

whether I say, "I may in the progress of experience discover stars, at a hundred times greater distance than the

most distant of those now visible," or, "Stars at this distance may be met in space, although no one has, or

ever will discover them." For, if they are given as things in themselves, without any relation to possible

experience, they are for me nonexistent, consequently, are not objects, for they are not contained in the

regressive series of experience. But, if these phenomena must be employed in the construction or support of

the cosmological idea of an absolute whole, and when we are discussing a question that oversteps the limits

of possible experience, the proper distinction of the different theories of the reality of sensuous objects is of

great importance, in order to avoid the illusion which must necessarily arise from the misinterpretation of our

The antinomy of pure reason is based upon the following dialectical argument: "If that which is conditioned

is given, the whole series of its conditions is also given; but sensuous objects are given as conditioned;

consequently..." This syllogism, the major of which seems so natural and evident, introduces as many

cosmological ideas as there are different kinds of conditions in the synthesis of phenomena, in so far as these

conditions constitute a series. These ideas require absolute totality in the series, and thus place reason in

inextricable embarrassment. Before proceeding to expose the fallacy in this dialectical argument, it will be

necessary to have a correct understanding of certain conceptions that appear in it.

In the first place, the following proposition is evident, and indubitably certain: "If the conditioned is given, a

regress in the series of all its conditions is thereby imperatively required." For the very conception of a

conditioned is a conception of something related to a condition, and, if this condition is itself conditioned, to

another condition and so on through all the members of the series. This proposition is, therefore, analytical

and has nothing to fear from transcendental criticism. It is a logical postulate of reason: to pursue, as far as

If, in the second place, both the conditioned and the condition are things in themselves, and if the former is

given, not only is the regress to the latter requisite, but the latter is really given with the former. Now, as this

is true of all the members of the series, the entire series of conditions, and with them the unconditioned, is at

the same time given in the very fact of the conditioned, the existence of which is possible only in and through

that series, being given. In this case, the synthesis of the conditioned with its condition, is a synthesis of the

understanding merely, which represents things as they are, without regarding whether and how we can

cognize them. But if I have to do with phenomena, which, in their character of mere representations, are not

given, if I do not attain to a cognition of them (in other words, to themselves, for they are nothing more than

empirical cognitions), I am not entitled to say: "If the conditioned is given, all its conditions (as phenomena)

are also given." I cannot, therefore, from the fact of a conditioned being given, infer the absolute totality of

the series of its conditions. For phenomena are nothing but an empirical synthesis in apprehension or

perception, and are therefore given only in it. Now, in speaking of phenomena it does not follow that, if the

conditioned is given, the synthesis which constitutes its empirical condition is also thereby given and

presupposed; such a synthesis can be established only by an actual regress in the series of conditions. But we

are entitled to say in this case that a regress to the conditions of a conditioned, in other words, that a

continuous empirical synthesis is enjoined; that, if the conditions are not given, they are at least required; and

We can now see that the major, in the above cosmological syllogism, takes the conditioned in the

transcendental signification which it has in the pure category, while the minor speaks of it in the empirical

signification which it has in the category as applied to phenomena. There is, therefore, a dialectical fallacy in

the syllogism a sophisma figurae dictionis. But this fallacy is not a consciously devised one, but a perfectly

natural illusion of the common reason of man. For, when a thing is given as conditioned, we presuppose in

the major its conditions and their series, unperceived, as it were, and unseen; because this is nothing more

than the logical requirement of complete and satisfactory premisses for a given conclusion. In this case, time

is altogether left out in the connection of the conditioned with the condition; they are supposed to be given in

themselves, and contemporaneously. It is, moreover, just as natural to regard phenomena (in the minor) as

things in themselves and as objects presented to the pure understanding, as in the major, in which complete

abstraction was made of all conditions of intuition. But it is under these conditions alone that objects are

given. Now we overlooked a remarkable distinction between the conceptions. The synthesis of the

conditioned with its condition, and the complete series of the latter (in the major) are not limited by time, and

do not contain the conception of succession. On the contrary, the empirical synthesis and the series of

conditions in the phenomenal world subsumed in the minor are necessarily successive and given in time

alone. It follows that I cannot presuppose in the minor, as I did in the major, the absolute totality of the

synthesis and of the series therein represented; for in the major all the members of the series are given as

things in themselves without any limitations or conditions of time, while in the minor they are possible only

in and through a successive regress, which cannot exist, except it be actually carried into execution in the

After this proof of the viciousness of the argument commonly employed in maintaining cosmological

assertions, both parties may now be justly dismissed, as advancing claims without grounds or title. But the

process has not been ended by convincing them that one or both were in the wrong and had maintained an

assertion which was without valid grounds of proof. Nothing seems to be clearer than that, if one maintains:

"The world has a beginning," and another: "The world has no beginning," one of the two must be right. But it

is likewise clear that, if the evidence on both sides is equal, it is impossible to discover on what side the truth

lies; and the controversy continues, although the parties have been recommended to peace before the tribunal

of reason. There remains, then, no other means of settling the question than to convince the parties, who

refute each other with such conclusiveness and ability, that they are disputing about nothing, and that a

transcendental illusion has been mocking them with visions of reality where there is none. The mode of

adjusting a dispute which cannot be decided upon its own merits, we shall now proceed to lay before our

Zeno of Elea, a subtle dialectician, was severely reprimanded by Plato as a sophist, who, merely from the

base motive of exhibiting his skill in discussion, maintained and subverted the same proposition by

arguments as powerful and convincing on the one side as on the other. He maintained, for example, that God

(who was probably nothing more, in his view, than the world) is neither finite nor infinite, neither in motion

nor in rest, neither similar nor dissimilar to any other thing. It seemed to those philosophers who criticized his

mode of discussion that his purpose was to deny completely both of two selfcontradictory propositions

which is absurd. But I cannot believe that there is any justice in this accusation. The first of these

propositions I shall presently consider in a more detailed manner. With regard to the others, if by the word of

God he understood merely the Universe, his meaning must have been that it cannot be permanently present

in one place that is, at rest nor be capable of changing its place that is, of moving because all places are

in the universe, and the universe itself is, therefore, in no place. Again, if the universe contains in itself

everything that exists, it cannot be similar or dissimilar to any other thing, because there is, in fact, no other

thing with which it can be compared. If two opposite judgements presuppose a contingent impossible, or

arbitrary condition, both in spite of their opposition (which is, however, not properly or really a

contradiction) fall away; because the condition, which ensured the validity of both, has itself disappeared.

If we say: "Everybody has either a good or a bad smell," we have omitted a third possible judgement it has

no smell at all; and thus both conflicting statements may be false. If we say: "It is either goodsmelling or not

goodsmelling (vel suaveolens vel nonsuaveolens)," both judgements are contradictorily opposed; and the

contradictory opposite of the former judgement some bodies are not goodsmelling embraces also those

bodies which have no smell at all. In the preceding pair of opposed judgements (per disparata), the contingent

condition of the conception of body (smell) attached to both conflicting statements, instead of having been

omitted in the latter, which is consequently not the contradictory opposite of the former.

If, accordingly, we say: "The world is either infinite in extension, or it is not infinite (non est infinitus)"; and

if the former proposition is false, its contradictory opposite the world is not infinite must be true. And thus

I should deny the existence of an infinite, without, however affirming the existence of a finite world. But if

we construct our proposition thus: "The world is either infinite or finite (noninfinite)," both statements may

be false. For, in this case, we consider the world as per se determined in regard to quantity, and while, in the

one judgement, we deny its infinite and consequently, perhaps, its independent existence; in the other, we

append to the world, regarded as a thing in itself, a certain determination that of finitude; and the latter may

be false as well as the former, if the world is not given as a thing in itself, and thus neither as finite nor as

infinite in quantity. This kind of opposition I may be allowed to term dialectical; that of contradictories may

be called analytical opposition. Thus then, of two dialectically opposed judgements both may be false, from

the fact, that the one is not a mere contradictory of the other, but actually enounces more than is requisite for

When we regard the two propositions "The world is infinite in quantity," and, "The world is finite in

quantity," as contradictory opposites, we are assuming that the world the complete series of phenomena is

a thing in itself. For it remains as a permanent quantity, whether I deny the infinite or the finite regress in the

series of its phenomena. But if we dismiss this assumption this transcendental illusion and deny that it is a

thing in itself, the contradictory opposition is metamorphosed into a merely dialectical one; and the world, as

not existing in itself independently of the regressive series of my representations exists in like manner

neither as a whole which is infinite nor as a whole which is finite in itself. The universe exists for me only in

the empirical regress of the series of phenomena and not per se. If, then, it is always conditioned, it is never

completely or as a whole; and it is, therefore, not an unconditioned whole and does not exist as such, either

What we have here said of the first cosmological idea that of the absolute totality of quantity in

phenomena applies also to the others. The series of conditions is discoverable only in the regressive

synthesis itself, and not in the phenomenon considered as a thing in itself given prior to all regress. Hence I

am compelled to say: "The aggregate of parts in a given phenomenon is in itself neither finite nor infinite;

and these parts are given only in the regressive synthesis of decomposition a synthesis which is never given

in absolute completeness, either as finite, or as infinite." The same is the case with the series of subordinated

causes, or of the conditioned up to the unconditioned and necessary existence, which can never be regarded

as in itself, ind in its totality, either as finite or as infinite; because, as a series of subordinate representations,

it subsists only in the dynamical regress and cannot be regarded as existing previously to this regress, or as a

Thus the antinomy of pure reason in its cosmological ideas disappears. For the above demonstration has

established the fact that it is merely the product of a dialectical and illusory opposition, which arises from the

application of the idea of absolute totality admissible only as a condition of things in themselves to

phenomena, which exist only in our representations, and when constituting a series in a successive regress.

This antinomy of reason may, however, be really profitable to our speculative interests, not in the way of

contributing any dogmatical addition, but as presenting to us another material support in our critical

investigations. For it furnishes us with an indirect proof of the transcendental ideality of phenomena, if our

minds were not completely satisfied with the direct proof set forth in the Trancendental Aesthetic. The proof

would proceed in the following dilemma. If the world is a whole existing in itself, it must be either finite or

infinite. But it is neither finite nor infinite as has been shown, on the one side, by the thesis, on the other, by

the antithesis. Therefore the world the content of all phenomena is not a whole existing in itself. It follows

that phenomena are nothing, apart from our representations. And this is what we mean by transcendental

This remark is of some importance. It enables us to see that the proofs of the fourfold antinomy are not mere

sophistries are not fallacious, but grounded on the nature of reason, and valid under the supposition that

phenomena are things in themselves. The opposition of the judgements which follow makes it evident that a

fallacy lay in the initial supposition, and thus helps us to discover the true constitution of objects of sense.

This transcendental dialectic does not favour scepticism, although it presents us with a triumphant

demonstration of the advantages of the sceptical method, the great utility of which is apparent in the

antinomy, where the arguments of reason were allowed to confront each other in undiminished force. And

although the result of these conflicts of reason is not what we expected although we have obtained no

positive dogmatical addition to metaphysical science we have still reaped a great advantage in the correction

The cosmological principle of totality could not give us any certain knowledge in regard to the maximum in

the series of conditions in the world of sense, considered as a thing in itself. The actual regress in the series is

the only means of approaching this maximum. This principle of pure reason, therefore, may still be

considered as valid not as an axiom enabling us to cogitate totality in the object as actual, but as a problem

for the understanding, which requires it to institute and to continue, in conformity with the idea of totality in

the mind, the regress in the series of the conditions of a given conditioned. For in the world of sense, that is,

SECTION VIII. Regulative Principle of Pure Reason in relation to the Cosmological Ideas. 172

in space and time, every condition which we discover in our investigation of phenomena is itself conditioned;

because sensuous objects are not things in themselves (in which case an absolutely unconditioned might be

reached in the progress of cognition), but are merely empirical representations the conditions of which must

always be found in intuition. The principle of reason is therefore properly a mere rule prescribing a regress

in the series of conditions for given phenomena, and prohibiting any pause or rest on an absolutely

unconditioned. It is, therefore, not a principle of the possibility of experience or of the empirical cognition of

sensuous objects consequently not a principle of the understanding; for every experience is confined within

certain proper limits determined by the given intuition. Still less is it a constitutive principle of reason

authorizing us to extend our conception of the sensuous world beyond all possible experience. It is merely a

principle for the enlargement and extension of experience as far as is possible for human faculties. It forbids

us to consider any empirical limits as absolute. It is, hence, a principle of reason, which, as a rule, dictates

how we ought to proceed in our empirical regress, but is unable to anticipate or indicate prior to the empirical

regress what is given in the object itself. I have termed it for this reason a regulative principle of reason;

while the principle of the absolute totality of the series of conditions, as existing in itself and given in the

object, is a constitutive cosmological principle. This distinction will at once demonstrate the falsehood of the

constitutive principle, and prevent us from attributing (by a transcendental subreptio) objective reality to an

In order to understand the proper meaning of this rule of pure reason, we must notice first that it cannot tell us

what the object is, but only how the empirical regress is to be proceeded with in order to attain to the

complete conception of the object. If it gave us any information in respect to the former statement, it would

be a constitutive principle a principle impossible from the nature of pure reason. It will not therefore enable

us to establish any such conclusions as: "The series of conditions for a given conditioned is in itself finite."

or, "It is infinite." For, in this case, we should be cogitating in the mere idea of absolute totality, an object

which is not and cannot be given in experience; inasmuch as we should be attributing a reality objective and

independent of the empirical synthesis, to a series of phenomena. This idea of reason cannot then be regarded

as valid except as a rule for the regressive synthesis in the series of conditions, according to which we must

proceed from the conditioned, through all intermediate and subordinate conditions, up to the unconditioned;

although this goal is unattained and unattainable. For the absolutely unconditioned cannot be discovered in

We now proceed to determine clearly our notion of a synthesis which can never be complete. There are two

terms commonly employed for this purpose. These terms are regarded as expressions of different and

distinguishable notions, although the ground of the distinction has never been clearly exposed. The term

employed by the mathematicians is progressus in infinitum. The philosophers prefer the expression

progressus in indefinitum. Without detaining the reader with an examination of the reasons for such a

distinction, or with remarks on the right or wrong use of the terms, I shall endeavour clearly to determine

We may, with propriety, say of a straight line, that it may be produced to infinity. In this case the distinction

between a progressus in infinitum and a progressus in indefinitum is a mere piece of subtlety. For, although

when we say, "Produce a straight line," it is more correct to say in indefinitum than in infinitum; because the

former means, "Produce it as far as you please," the second, "You must not cease to produce it"; the

expression in infinitum is, when we are speaking of the power to do it, perfectly correct, for we can always

make it longer if we please on to infinity. And this remark holds good in all cases, when we speak of a

progressus, that is, an advancement from the condition to the conditioned; this possible advancement always

proceeds to infinity. We may proceed from a given pair in the descending line of generation from father to

son, and cogitate a neverending line of descendants from it. For in such a case reason does not demand

absolute totality in the series, because it does not presuppose it as a condition and as given (datum), but

SECTION VIII. Regulative Principle of Pure Reason in relation to the Cosmological Ideas. 173

Very different is the case with the problem: "How far the regress, which ascends from the given conditioned

to the conditions, must extend"; whether I can say: "It is a regress in infinitum," or only "in indefinitum"; and

whether, for example, setting out from the human beings at present alive in the world, I may ascend in the

series of their ancestors, in infinitum mr whether all that can be said is, that so far as I have proceeded, I

have discovered no empirical ground for considering the series limited, so that I am justified, and indeed,

compelled to search for ancestors still further back, although I am not obliged by the idea of reason to

My answer to this question is: "If the series is given in empirical intuition as a whole, the regress in the series

of its internal conditions proceeds in infinitum; but, if only one member of the series is given, from which the

regress is to proceed to absolute totality, the regress is possible only in indefinitum." For example, the

division of a portion of matter given within certain limits of a body, that is proceeds in infinitum. For, as

the condition of this whole is its part, and the condition of the part a part of the part, and so on, and as in this

regress of decomposition an unconditioned indivisible member of the series of conditions is not to be found;

there are no reasons or grounds in experience for stopping in the division, but, on the contrary, the more

remote members of the division are actually and empirically given prior to this division. That is to say, the

division proceeds to infinity. On the other hand, the series of ancestors of any given human being is not

given, in its absolute totality, in any experience, and yet the regress proceeds from every genealogical

member of this series to one still higher, and does not meet with any empirical limit presenting an absolutely

unconditioned member of the series. But as the members of such a series are not contained in the empirical

intuition of the whole, prior to the regress, this regress does not proceed to infinity, but only in indefinitum,

that is, we are called upon to discover other and higher members, which are themselves always conditioned.

In neither case the regressus in infinitum, nor the regressus in indefinitum, is the series of conditions to be

considered as actually infinite in the object itself. This might be true of things in themselves, but it cannot be

asserted of phenomena, which, as conditions of each other, are only given in the empirical regress itself.

Hence, the question no longer is, "What is the quantity of this series of conditions in itself is it finite or

infinite?" for it is nothing in itself; but, "How is the empirical regress to be commenced, and how far ought

we to proceed with it?" And here a signal distinction in the application of this rule becomes apparent. If the

whole is given empirically, it is possible to recede in the series of its internal conditions to infinity. But if the

whole is not given, and can only be given by and through the empirical regress, I can only say: "It is possible

to infinity, to proceed to still higher conditions in the series." In the first case, I am justified in asserting that

more members are empirically given in the object than I attain to in the regress (of decomposition). In the

second case, I am justified only in saying, that I can always proceed further in the regress, because no

member of the series. is given as absolutely conditioned, and thus a higher member is possible, and an

inquiry with regard to it is necessary. In the one case it is necessary to find other members of the series, in the

other it is necessary to inquire for others, inasmuch as experience presents no absolute limitation of the

regress. For, either you do not possess a perception which absolutely limits your empirical regress, and in this

case the regress cannot be regarded as complete; or, you do possess such a limitative perception, in which

case it is not a part of your series (for that which limits must be distinct from that which is limited by it), and

These remarks will be placed in their proper light by their application in the following section.

We have shown that no transcendental use can be made either of the conceptions of reason or of

understanding. We have shown, likewise, that the demand of absolute totality in the series of conditions in

the world of sense arises from a transcendental employment of reason, resting on the opinion that phenomena

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are to be regarded as things in themselves. It follows that we are not required to answer the question

respecting the absolute quantity of a series whether it is in itself limited or unlimited. We are only called

upon to determine how far we must proceed in the empirical regress from condition to condition, in order to

discover, in conformity with the rule of reason, a full and correct answer to the questions proposed by reason

This principle of reason is hence valid only as a rule for the extension of a possible experience its invalidity

as a principle constitutive of phenomena in themselves having been sufficiently demonstrated. And thus, too,

the antinomial conflict of reason with itself is completely put an end to; inasmuch as we have not only

presented a critical solution of the fallacy lurking in the opposite statements of reason, but have shown the

true meaning of the ideas which gave rise to these statements. The dialectical principle of reason has,

therefore, been changed into a doctrinal principle. But in fact, if this principle, in the subjective signification

which we have shown to be its only true sense, may be guaranteed as a principle of the unceasing extension

of the employment of our understanding, its influence and value are just as great as if it were an axiom for the

a priori determination of objects. For such an axiom could not exert a stronger influence on the extension and

rectification of our knowledge, otherwise than by procuring for the principles of the understanding the most

Here, as well as in the case of the other cosmological problems, the ground of the regulative principle of

reason is the proposition that in our empirical regress no experience of an absolute limit, and consequently no

experience of a condition, which is itself absolutely unconditioned, is discoverable. And the truth of this

proposition itself rests upon the consideration that such an experience must represent to us phenomena as

limited by nothing or the mere void, on which our continued regress by means of perception must abut

Now this proposition, which declares that every condition attained in the empirical regress must itself be

considered empirically conditioned, contains the rule in terminis, which requires me, to whatever extent I

may have proceeded in the ascending series, always to look for some higher member in the series whether

Nothing further is necessary, then, for the solution of the first cosmological problem, than to decide, whether,

in the regress to the unconditioned quantity of the universe (as regards space and time), this never limited

The general representation which we form in our minds of the series of all past states or conditions of the

world, or of all the things which at present exist in it, is itself nothing more than a possible empirical regress,

which is cogitated although in an undetermined manner in the mind, and which gives rise to the conception

of a series of conditions for a given object.* Now I have a conception of the universe, but not an intuition

that is, not an intuition of it as a whole. Thus I cannot infer the magnitude of the regress from the quantity or

magnitude of the world, and determine the former by means of the latter; on the contrary, I must first of all

form a conception of the quantity or magnitude of the world from the magnitude of the empirical regress. But

of this regress I know nothing more than that I ought to proceed from every given member of the series of

conditions to one still higher. But the quantity of the universe is not thereby determined, and we cannot

affirm that this regress proceeds in infinitum. Such an affirmation would anticipate the members of the series

which have not yet been reached, and represent the number of them as beyond the grasp of any empirical

synthesis; it would consequently determine the cosmical quantity prior to the regress (although only in a

negative manner) which is impossible. For the world is not given in its totality in any intuition:

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consequently, its quantity cannot be given prior to the regress. It follows that we are unable to make any

declaration respecting the cosmical quantity in itself not even that the regress in it is a regress in infinitum;

we must only endeavour to attain to a conception of the quantity of the universe, in conformity with the rule

which determines the empirical regress in it. But this rule merely requires us never to admit an absolute limit

to our series how far soever we may have proceeded in it, but always, on the contrary, to subordinate every

phenomenon to some other as its condition, and consequently to proceed to this higher phenomenon. Such a

regress is, therefore, the regressus in indefinitum, which, as not determining a quantity in the object, is clearly

*The cosmical series can neither be greater nor smaller than the possible empirical regress, upon which its

conception is based. And as this regress cannot be a determinate infinite regress, still less a determinate finite

(absolutely limited), it is evident that we cannot regard the world as either finite or infinite, because the

regress, which gives us the representation of the world, is neither finite nor infinite.

It follows from what we have said that we are not justified in declaring the world to be infinite in space, or as

regards past time. For this conception of an infinite given quantity is empirical; but we cannot apply the

conception of an infinite quantity to the world as an object of the senses. I cannot say, "The regress from a

given perception to everything limited either in space or time, proceeds in infinitum," for this presupposes an

infinite cosmical quantity; neither can I say, "It is finite," for an absolute limit is likewise impossible in

experience. It follows that I am not entitled to make any assertion at all respecting the whole object of

experience the world of sense; I must limit my declarations to the rule according to which experience or

To the question, therefore, respecting the cosmical quantity, the first and negative answer is: "The world has

For, in the contrary case, it would be limited by a void time on the one hand, and by a void space on the

other. Now, since the world, as a phenomenon, cannot be thus limited in itself for a phenomenon is not a

thing in itself; it must be possible for us to have a perception of this limitation by a void time and a void

space. But such a perception such an experience is impossible; because it has no content. Consequently, an

*The reader will remark that the proof presented above is very different from the dogmatical demonstration

given in the antithesis of the first antinomy. In that demonstration, it was taken for granted that the world is a

thing in itself given in its totality prior to all regress, and a determined position in space and time was

denied to it if it was not considered as occupying all time and all space. Hence our conclusion differed from

that given above; for we inferred in the antithesis the actual infinity of the world.

From this follows the affirmative answer: "The regress in the series of phenomena as a determination of the

cosmical quantity, proceeds in indefinitum." This is equivalent to saying: "The world of sense has no absolute

quantity, but the empirical regress (through which alone the world of sense is presented to us on the side of its

conditions) rests upon a rule, which requires it to proceed from every member of the series, as conditioned, to

one still more remote (whether through personal experience, or by means of history, or the chain of cause and

effect), and not to cease at any point in this extension of the possible empirical employment of the

understanding." And this is the proper and only use which reason can make of its principles.

The above rule does not prescribe an unceasing regress in one kind of phenomena. It does not, for example,

forbid us, in our ascent from an individual human being through the line of his ancestors, to expect that we

shall discover at some point of the regress a primeval pair, or to admit, in the series of heavenly bodies, a sun

at the farthest possible distance from some centre. All that it demands is a perpetual progress from

phenomena to phenomena, even although an actual perception is not presented by them (as in the case of our

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perceptions being so weak as that we are unable to become conscious of them), since they, nevertheless,

Every beginning is in time, and all limits to extension are in space. But space and time are in the world of

sense. Consequently phenomena in the world are conditionally limited, but the world itself is not limited,

For this reason, and because neither the world nor the cosmical series of conditions to a given conditioned

can be completely given, our conception of the cosmical quantity is given only in and through the regress and

not prior to it in a collective intuition. But the regress itself is really nothing more than the determining of

the cosmical quantity, and cannot therefore give us any determined conception of it still less a conception of

a quantity which is, in relation to a certain standard, infinite. The regress does not, therefore, proceed to

infinity (an infinity given), but only to an indefinite extent, for or the of presenting to us a quantity realized

When I divide a whole which is given in intuition, I proceed from a conditioned to its conditions. The

division of the parts of the whole (subdivisio or decompositio) is a regress in the series of these conditions.

The absolute totality of this series would be actually attained and given to the mind, if the regress could arrive

at simple parts. But if all the parts in a continuous decomposition are themselves divisible, the division, that

is to say, the regress, proceeds from the conditioned to its conditions in infinitum; because the conditions (the

parts) are themselves contained in the conditioned, and, as the latter is given in a limited intuition, the former

are all given along with it. This regress cannot, therefore, be called a regressus in indefinitum, as happened in

the case of the preceding cosmological idea, the regress in which proceeded from the conditioned to the

conditions not given contemporaneously and along with it, but discoverable only through the empirical

regress. We are not, however, entitled to affirm of a whole of this kind, which is divisible in infinitum, that it

consists of an infinite number of parts. For, although all the parts are contained in the intuition of the whole,

the whole division is not contained therein. The division is contained only in the progressing decomposition

in the regress itself, which is the condition of the possibility and actuality of the series. Now, as this regress is

infinite, all the members (parts) to which it attains must be contained in the given whole as an aggregate. But

the complete series of division is not contained therein. For this series, being infinite in succession and

always incomplete, cannot represent an infinite number of members, and still less a composition of these

To apply this remark to space. Every limited part of space presented to intuition is a whole, the parts of which

are always spaces to whatever extent subdivided. Every limited space is hence divisible to infinity.

Let us again apply the remark to an external phenomenon enclosed in limits, that is, a body. The divisibility

of a body rests upon the divisibility of space, which is the condition of the possibility of the body as an

extended whole. A body is consequently divisible to infinity, though it does not, for that reason, consist of an

It certainly seems that, as a body must be cogitated as substance in space, the law of divisibility would not be

applicable to it as substance. For we may and ought to grant, in the case of space, that division or

decomposition, to any extent, never can utterly annihilate composition (that is to say, the smallest part of

space must still consist of spaces); otherwise space would entirely cease to exist which is impossible. But,

the assertion on the other band that when all composition in matter is annihilated in thought, nothing remains,

does not seem to harmonize with the conception of substance, which must be properly the subject of all

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composition and must remain, even after the conjunction of its attributes in space which constituted a body

is annihilated in thought. But this is not the case with substance in the phenomenal world, which is not a thing

in itself cogitated by the pure category. Phenomenal substance is not an absolute subject; it is merely a

permanent sensuous image, and nothing more than an intuition, in which the unconditioned is not to be

But, although this rule of progress to infinity is legitimate and applicable to the subdivision of a phenomenon,

as a mere occupation or filling of space, it is not applicable to a whole consisting of a number of distinct parts

and constituting a quantum discretum that is to say, an organized body. It cannot be admitted that every part

in an organized whole is itself organized, and that, in analysing it to infinity, we must always meet with

organized parts; although we may allow that the parts of the matter which we decompose in infinitum, may

be organized. For the infinity of the division of a phenomenon in space rests altogether on the fact that the

divisibility of a phenomenon is given only in and through this infinity, that is, an undetermined number of

parts is given, while the parts themselves are given and determined only in and through the subdivision; in a

word, the infinity of the division necessarily presupposes that the whole is not already divided in se. Hence

our division determines a number of parts in the whole a number which extends just as far as the actual

regress in the division; while, on the other hand, the very notion of a body organized to infinity represents the

whole as already and in itself divided. We expect, therefore, to find in it a determinate, but at the same time,

infinite, number of parts which is selfcontradictory. For we should thus have a whole containing a series of

members which could not be completed in any regress which is infinite, and at the same time complete in an

organized composite. Infinite divisibility is applicable only to a quantum continuum, and is based entirely on

the infinite divisibility of space, But in a quantum discretum the multitude of parts or units is always

determined, and hence always equal to some number. To what extent a body may be organized, experience

alone can inform us; and although, so far as our experience of this or that body has extended, we may not

have discovered any inorganic part, such parts must exist in possible experience. But how far the

transcendental division of a phenomenon must extend, we cannot know from experience it is a question

which experience cannot answer; it is answered only by the principle of reason which forbids us to consider

the empirical regress, in the analysis of extended body, as ever absolutely complete.

We presented the antinomy of pure reason in a tabular form, and we endeavoured to show the ground of this

selfcontradiction on the part of reason, and the only means of bringing it to a conclusion znamely, by

declaring both contradictory statements to be false. We represented in these antinomies the conditions of

phenomena as belonging to the conditioned according to relations of space and time which is the usual

supposition of the common understanding. In this respect, all dialectical representations of totality, in the

series of conditions to a given conditioned, were perfectly homogeneous. The condition was always a

member of the series along with the conditioned, and thus the homogeneity of the whole series was assured.

In this case the regress could never be cogitated as complete; or, if this was the case, a member really

conditioned was falsely regarded as a primal member, consequently as unconditioned. In such an antinomy,

therefore, we did not consider the object, that is, the conditioned, but the series of conditions belonging to the

object, and the magnitude of that series. And thus arose the difficulty a difficulty not to be settled by any

decision regarding the claims of the two parties, but simply by cutting the knot by declaring the series

proposed by reason to be either too long or too short for the understanding, which could in neither case make

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But we have overlooked, up to this point, an essential difference existing between the conceptions of the

understanding which reason endeavours to raise to the rank of ideas two of these indicating a mathematical,

and two a dynamical synthesis of phenomena. Hitherto, it was necessary to signalize this distinction; for, just

as in our general representation of all transcendental ideas, we considered them under phenomenal

conditions, so, in the two mathematical ideas, our discussion is concerned solely with an object in the world

of phenomena. But as we are now about to proceed to the consideration of the dynamical conceptions of the

understanding, and their adequateness with ideas, we must not lose sight of this distinction. We shall find that

it opens up to us an entirely new view of the conflict in which reason is involved. For, while in the first two

antinomies, both parties were dismissed, on the ground of having advanced statements based upon false

hypothesis; in the present case the hope appears of discovering a hypothesis which may be consistent with the

demands of reason, and, the judge completing the statement of the grounds of claim, which both parties had

left in an unsatisfactory state, the question may be settled on its own merits, not by dismissing the claimants,

but by a comparison of the arguments on both sides. If we consider merely their extension, and whether they

are adequate with ideas, the series of conditions may be regarded as all homogeneous. But the conception of

the understanding which lies at the basis of these ideas, contains either a synthesis of the homogeneous

(presupposed in every quantity in its composition as well as in its division) or of the heterogeneous, which

is the case in the dynamical synthesis of cause and effect, as well as of the necessary and the contingent.

Thus it happens that in the mathematical series of phenomena no other than a sensuous condition is

admissible a condition which is itself a member of the series; while the dynamical series of sensuous

conditions admits a heterogeneous condition, which is not a member of the series, but, as purely intelligible,

lies out of and beyond it. And thus reason is satisfied, and an unconditioned placed at the head of the series of

phenomena, without introducing confusion into or discontinuing it, contrary to the principles of the

Now, from the fact that the dynamical ideas admit a condition of phenomena which does not form a part of

the series of phenomena, arises a result which we should not have expected from an antinomy. In former

cases, the result was that both contradictory dialectical statements were declared to be false. In the present

case, we find the conditioned in the dynamical series connected with an empirically unconditioned, but

nonsensuous condition; and thus satisfaction is done to the understanding on the one hand and to the reason

on the other.* While, moreover, the dialectical arguments for unconditioned totality in mere phenomena fall

to the ground, both propositions of reason may be shown to be true in their proper signification. This could

not happen in the case of the cosmological ideas which demanded a mathematically unconditioned unity; for

no condition could be placed at the head of the series of phenomena, except one which was itself a

*For the understanding cannot admit among phenomena a condition which is itself empirically

unconditioned. But if it is possible to cogitate an intelligible condition one which is not a member of the

series of phenomena for a conditioned phenomenon, without breaking the series of empirical conditions,

such a condition may be admissible as empirically unconditioned, and the empirical regress continue regular,

There are only two modes of causality cogitable the causality of nature or of freedom. The first is the

conjunction of a particular state with another preceding it in the world of sense, the former following the

latter by virtue of a law. Now, as the causality of phenomena is subject to conditions of time, and the

preceding state, if it had always existed, could not have produced an effect which would make its first

appearance at a particular time, the causality of a cause must itself be an effect must itself have begun to be,

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and therefore, according to the principle of the understanding, itself requires a cause.

We must understand, on the contrary, by the term freedom, in the cosmological sense, a faculty of the

spontaneous origination of a state; the causality of which, therefore, is not subordinated to another cause

determining it in time. Freedom is in this sense a pure transcendental idea, which, in the first place, contains

no empirical element; the object of which, in the second place, cannot be given or determined in any

experience, because it is a universal law of the very possibility of experience, that everything which happens

must have a cause, that consequently the causality of a cause, being itself something that has happened, must

also have a cause. In this view of the case, the whole field of experience, how far soever it may extend,

contains nothing that is not subject to the laws of nature. But, as we cannot by this means attain to an absolute

totality of conditions in reference to the series of causes and effects, reason creates the idea of a spontaneity,

which can begin to act of itself, and without any external cause determining it to action, according to the

It is especially remarkable that the practical conception of freedom is based upon the transcendental idea, and

that the question of the possibility of the former is difficult only as it involves the consideration of the truth of

the latter. Freedom, in the practical sense, is the independence of the will of coercion by sensuous impulses.

A will is sensuous, in so far as it is pathologically affected (by sensuous impulses); it is termed animal

(arbitrium brutum), when it is pathologically necessitated. The human will is certainly an arbitrium

sensitivum, not brutum, but liberum; because sensuousness does not necessitate its action, a faculty existing

It is plain that, if all causality in the world of sense were natural and natural only every event would be

determined by another according to necessary laws, and that, consequently, phenomena, in so far as they

determine the will, must necessitate every action as a natural effect from themselves; and thus all practical

freedom would fall to the ground with the transcendental idea. For the latter presupposes that although a

certain thing has not happened, it ought to have happened, and that, consequently, its phenomenal cause was

not so powerful and determinative as to exclude the causality of our will a causality capable of producing

effects independently of and even in opposition to the power of natural causes, and capable, consequently, of

Here, too, we find it to be the case, as we generally found in the selfcontradictions and perplexities of a

reason which strives to pass the bounds of possible experience, that the problem is properly not physiological,

but transcendental. The question of the possibility of freedom does indeed concern psychology; but, as it rests

upon dialectical arguments of pure reason, its solution must engage the attention of transcendental

philosophy. Before attempting this solution, a task which transcendental philosophy cannot decline, it will be

advisable to make a remark with regard to its procedure in the settlement of the question.

If phenomena were things in themselves, and time and space forms of the existence of things, condition and

conditioned would always be members of the same series; and thus would arise in the present case the

antinomy common to all transcendental ideas that their series is either too great or too small for the

understanding. The dynamical ideas, which we are about to discuss in this and the following section, possess

the peculiarity of relating to an object, not considered as a quantity, but as an existence; and thus, in the

discussion of the present question, we may make abstraction of the quantity of the series of conditions, and

consider merely the dynamical relation of the condition to the conditioned. The question, then, suggests itself,

whether freedom is possible; and, if it is, whether it can consist with the universality of the natural law of

causality; and, consequently, whether we enounce a proper disjunctive proposition when we say: "Every

effect must have its origin either in nature or in freedom," or whether both cannot exist together in the same

event in different relations. The principle of an unbroken connection between all events in the phenomenal

world, in accordance with the unchangeable laws of nature, is a wellestablished principle of transcendental

analytic which admits of no exception. The question, therefore, is: "Whether an effect, determined according

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to the laws of nature, can at the same time be produced by a free agent, or whether freedom and nature

mutually exclude each other?" And here, the common but fallacious hypothesis of the absolute reality of

phenomena manifests its injurious influence in embarrassing the procedure of reason. For if phenomena are

things in themselves, freedom is impossible. In this case, nature is the complete and allsufficient cause of

every event; and condition and conditioned, cause and effect are contained in the same series, and

necessitated by the same law. If, on the contrary, phenomena are held to be, as they are in fact, nothing more

than mere representations, connected with each other in accordance with empirical laws, they must have a

ground which is not phenomenal. But the causality of such an intelligible cause is not determined or

determinable by phenomena; although its effects, as phenomena, must be determined by other phenomenal

existences. This cause and its causality exist therefore out of and apart from the series of phenomena; while

its effects do exist and are discoverable in the series of empirical conditions. Such an effect may therefore be

considered to be free in relation to its intelligible cause, and necessary in relation to the phenomena from

which it is a necessary consequence a distinction which, stated in this perfectly general and abstract manner,

must appear in the highest degree subtle and obscure. The sequel will explain. It is sufficient, at present, to

remark that, as the complete and unbroken connection of phenomena is an unalterable law of nature, freedom

is impossible on the supposition that phenomena are absolutely real. Hence those philosophers who adhere

to the common opinion on this subject can never succeed in reconciling the ideas of nature and freedom.

That element in a sensuous object which is not itself sensuous, I may be allowed to term intelligible. If,

accordingly, an object which must be regarded as a sensuous phenomenon possesses a faculty which is not an

object of sensuous intuition, but by means of which it is capable of being the cause of phenomena, the

causality of an object or existence of this kind may be regarded from two different points of view. It may be

considered to be intelligible, as regards its action the action of a thing which is a thing in itself, and

sensuous, as regards its effects the effects of a phenomenon belonging to the sensuous world. We should

accordingly, have to form both an empirical and an intellectual conception of the causality of such a faculty

or power both, however, having reference to the same effect. This twofold manner of cogitating a power

residing in a sensuous object does not run counter to any of the conceptions which we ought to form of the

world of phenomena or of a possible experience. Phenomena not being things in themselves must have a

transcendental object as a foundation, which determines them as mere representations; and there seems to be

no reason why we should not ascribe to this transcendental object, in addition to the property of

selfphenomenization, a causality whose effects are to be met with in the world of phenomena, although it is

not itself a phenomenon. But every effective cause must possess a character, that is to say, a law of its

causality, without which it would cease to be a cause. In the above case, then, every sensuous object would

possess an empirical character, which guaranteed that its actions, as phenomena, stand in complete and

harmonious connection, conformably to unvarying natural laws, with all other phenomena, and can be

deduced from these, as conditions, and that they do thus, in connection with these, constitute a series in the

order of nature. This sensuous object must, in the second place, possess an intelligible character, which

guarantees it to be the cause of those actions, as phenomena, although it is not itself a phenomenon nor

subordinate to the conditions of the world of sense. The former may be termed the character of the thing as a

Now this active subject would, in its character of intelligible subject, be subordinate to no conditions of time,

for time is only a condition of phenomena, and not of things in themselves. No action would begin or cease to

be in this subject; it would consequently be free from the law of all determination of time the law of change,

namely, that everything which happens must have a cause in the phenomena of a preceding state. In one

word, the causality of the subject, in so far as it is intelligible, would not form part of the series of empirical

conditions which determine and necessitate an event in the world of sense. Again, this intelligible character

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of a thing cannot be immediately cognized, because we can perceive nothing but phenomena, but it must be

capable of being cogitated in harmony with the empirical character; for we always find ourselves compelled

to place, in thought, a transcendental object at the basis of phenomena although we can never know what this

In virtue of its empirical character, this subject would at the same time be subordinate to all the empirical

laws of causality, and, as a phenomenon and member of the sensuous world, its effects would have to be

accounted for by a reference to preceding phenomena. Eternal phenomena must be capable of influencing it;

and its actions, in accordance with natural laws, must explain to us how its empirical character, that is, the

law of its causality, is to be cognized in and by means of experience. In a word, all requisites for a complete

and necessary determination of these actions must be presented to us by experience.

In virtue of its intelligible character, on the other hand (although we possess only a general conception of this

character), the subject must be regarded as free from all sensuous influences, and from all phenomenal

determination. Moreover, as nothing happens in this subject for it is a noumenon, and there does not

consequently exist in it any change, demanding the dynamical determination of time, and for the same reason

no connection with phenomena as causes this active existence must in its actions be free from and

independent of natural necessity, for or necessity exists only in the world of phenomena. It would be quite

correct to say that it originates or begins its effects in the world of sense from itself, although the action

productive of these effects does not begin in itself. We should not be in this case affirming that these

sensuous effects began to exist of themselves, because they are always determined by prior empirical

conditions by virtue of the empirical character, which is the phenomenon of the intelligible character and

are possible only as constituting a continuation of the series of natural causes. And thus nature and freedom,

each in the complete and absolute signification of these terms, can exist, without contradiction or

I have thought it advisable to lay before the reader at first merely a sketch of the solution of this

transcendental problem, in order to enable him to form with greater ease a clear conception of the course

which reason must adopt in the solution. I shall now proceed to exhibit the several momenta of this solution,

The natural law that everything which happens must have a cause, that the causality of this cause, that is, the

action of the cause (which cannot always have existed, but must be itself an event, for it precedes in time

some effect which it has originated), must have itself a phenomenal cause, by which it is determined and,

and, consequently, all events are empirically determined in an order of nature this law, I say, which lies at

the foundation of the possibility of experience, and of a connected system of phenomena or nature is a law of

the understanding, from which no departure, and to which no exception, can be admitted. For to except even

a single phenomenon from its operation is to exclude it from the sphere of possible experience and thus to

Thus we are obliged to acknowledge the existence of a chain of causes, in which, however, absolute totality

cannot be found. But we need not detain ourselves with this question, for it has already been sufficiently

answered in our discussion of the antinomies into which reason falls, when it attempts to reach the

unconditioned in the series of phenomena. If we permit ourselves to be deceived by the illusion of

transcendental idealism, we shall find that neither nature nor freedom exists. Now the question is: "Whether,

admitting the existence of natural necessity in the world of phenomena, it is possible to consider an effect as

at the same time an effect of nature and an effect of freedom or, whether these two modes of causality are

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No phenomenal cause can absolutely and of itself begin a series. Every action, in so far as it is productive of

an event, is itself an event or occurrence, and presupposes another preceding state, in which its cause existed.

Thus everything that happens is but a continuation of a series, and an absolute beginning is impossible in the

sensuous world. The actions of natural causes are, accordingly, themselves effects, and presuppose causes

preceding them in time. A primal action which forms an absolute beginning, is beyond the causal power of

Now, is it absolutely necessary that, granting that all effects are phenomena, the causality of the cause of

these effects must also be a phenomenon and belong to the empirical world? Is it not rather possible that,

although every effect in the phenomenal world must be connected with an empirical cause, according to the

universal law of nature, this empirical causality may be itself the effect of a nonempirical and intelligible

causality its connection with natural causes remaining nevertheless intact? Such a causality would be

considered, in reference to phenomena, as the primal action of a cause, which is in so far, therefore, not

phenomenal, but, by reason of this faculty or power, intelligible; although it must, at the same time, as a link

A belief in the reciprocal causality of phenomena is necessary, if we are required to look for and to present

the natural conditions of natural events, that is to say, their causes. This being admitted as unexceptionably

valid, the requirements of the understanding, which recognizes nothing but nature in the region of

phenomena, are satisfied, and our physical explanations of physical phenomena may proceed in their regular

course, without hindrance and without opposition. But it is no stumblingblock in the way, even assuming

the idea to be a pure fiction, to admit that there are some natural causes in the possession of a faculty which is

not empirical, but intelligible, inasmuch as it is not determined to action by empirical conditions, but purely

and solely upon grounds brought forward by the understanding this action being still, when the cause is

phenomenized, in perfect accordance with the laws of empirical causality. Thus the acting subject, as a causal

phenomenon, would continue to preserve a complete connection with nature and natural conditions; and the

phenomenon only of the subject (with all its phenomenal causality) would contain certain conditions, which,

if we ascend from the empirical to the transcendental object, must necessarily be regarded as intelligible. For,

if we attend, in our inquiries with regard to causes in the world of phenomena, to the directions of nature

alone, we need not trouble ourselves about the relation in which the transcendental subject, which is

completely unknown to us, stands to these phenomena and their connection in nature. The intelligible ground

of phenomena in this subject does not concern empirical questions. It has to do only with pure thought; and,

although the effects of this thought and action of the pure understanding are discoverable in phenomena,

these phenomena must nevertheless be capable of a full and complete explanation, upon purely physical

grounds and in accordance with natural laws. And in this case we attend solely to their empirical and omit all

consideration of their intelligible character (which is the transcendental cause of the former) as completely

unknown, except in so far as it is exhibited by the latter as its empirical symbol. Now let us apply this to

experience. Man is a phenomenon of the sensuous world and, at the same time, therefore, a natural cause, the

causality of which must be regulated by empirical laws. As such, he must possess an empirical character, like

all other natural phenomena. We remark this empirical character in his actions, which reveal the presence of

certain powers and faculties. If we consider inanimate or merely animal nature, we can discover no reason for

ascribing to ourselves any other than a faculty which is determined in a purely sensuous manner. But man, to

whom nature reveals herself only through sense, cognizes himself not only by his senses, but also through

pure apperception; and this in actions and internal determinations, which he cannot regard as sensuous

impressions. He is thus to himself, on the one hand, a phenomenon, but on the other hand, in respect of

certain faculties, a purely intelligible object intelligible, because its action cannot be ascribed to sensuous

receptivity. These faculties are understanding and reason. The latter, especially, is in a peculiar manner

distinct from all empiricallyconditioned faculties, for it employs ideas alone in the consideration of its

objects, and by means of these determines the understanding, which then proceeds to make an empirical use

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of its own conceptions, which, like the ideas of reason, are pure and nonempirical.

That reason possesses the faculty of causality, or that at least we are compelled so to represent it, is evident

from the imperatives, which in the sphere of the practical we impose on many of our executive powers. The

words I ought express a species of necessity, and imply a connection with grounds which nature does not and

cannot present to the mind of man. Understanding knows nothing in nature but that which is, or has been, or

will be. It would be absurd to say that anything in nature ought to be other than it is in the relations of time in

which it stands; indeed, the ought, when we consider merely the course of nature, bas neither application nor

meaning. The question, "What ought to happen in the sphere of nature?" is just as absurd as the question,

"What ought to be the properties of a circle?" All that we are entitled to ask is, "What takes place in nature?"

But the idea of an ought or of duty indicates a possible action, the ground of which is a pure conception;

while the ground of a merely natural action is, on the contrary, always a phenomenon. This action must

certainly be possible under physical conditions, if it is prescribed by the moral imperative ought; but these

physical or natural conditions do not concern the determination of the will itself, they relate to its effects

alone, and the consequences of the effect in the world of phenomena. Whatever number of motives nature

may present to my will, whatever sensuous impulses the moral ought it is beyond their power to produce.

They may produce a volition, which, so far from being necessary, is always conditioned a volition to which

the ought enunciated by reason, sets an aim and a standard, gives permission or prohibition. Be the object

what it may, purely sensuous as pleasure, or presented by pure reason as good, reason will not yield to

grounds which have an empirical origin. Reason will not follow the order of things presented by experience,

but, with perfect spontaneity, rearranges them according to ideas, with which it compels empirical conditions

to agree. It declares, in the name of these ideas, certain actions to be necessary which nevertheless have not

taken place and which perhaps never will take place; and yet presupposes that it possesses the faculty of

causality in relation to these actions. For, in the absence of this supposition, it could not expect its ideas to

Now, let us stop here and admit it to be at least possible that reason does stand in a really causal relation to

phenomena. In this case it must pure reason as it is exhibit an empirical character. For every cause

supposes a rule, according to which certain phenomena follow as effects from the cause, and every rule

requires uniformity in these effects; and this is the proper ground of the conception of a cause as a faculty or

power. Now this conception (of a cause) may be termed the empirical character of reason; and this character

is a permanent one, while the effects produced appear, in conformity with the various conditions which

Thus the volition of every man has an empirical character, which is nothing more than the causality of his

reason, in so far as its effects in the phenomenal world manifest the presence of a rule, according to which we

are enabled to examine, in their several kinds and degrees, the actions of this causality and the rational

grounds for these actions, and in this way to decide upon the subjective principles of the volition. Now we

learn what this empirical character is only from phenomenal effects, and from the rule of these which is

presented by experience; and for this reason all the actions of man in the world of phenomena are determined

by his empirical character, and the cooperative causes of nature. If, then, we could investigate all the

phenomena of human volition to their lowest foundation in the mind, there would be no action which we

could not anticipate with certainty, and recognize to be absolutely necessary from its preceding conditions. So

far as relates to this empirical character, therefore, there can be no freedom; and it is only in the light of this

character that we can consider the human will, when we confine ourselves to simple observation and, as is the

case in anthropology, institute a physiological investigation of the motive causes of human actions.

But when we consider the same actions in relation to reason not for the purpose of explaining their origin,

that is, in relation to speculative reason, but to practical reason, as the producing cause of these actions we

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shall discover a rule and an order very different from those of nature and experience. For the declaration of

this mental faculty may be that what has and could not but take place in the course of nature, ought not to

have taken place. Sometimes, too, we discover, or believe that we discover, that the ideas of reason did

actually stand in a causal relation to certain actions of man; and that these actions have taken place because

they were determined, not by empirical causes, but by the act of the will upon grounds of reason.

Now, granting that reason stands in a causal relation to phenomena; can an action of reason be called free,

when we know that, sensuously, in its empirical character, it is completely determined and absolutely

necessary? But this empirical character is itself determined by the intelligible character. The latter we cannot

cognize; we can only indicate it by means of phenomena, which enable us to have an immediate cognition

only of the empirical character.* An action, then, in so far as it is to be ascribed to an intelligible cause, does

not result from it in accordance with empirical laws. That is to say, not the conditions of pure reason, but only

their effects in the internal sense, precede the act. Pure reason, as a purely intelligible faculty, is not subject to

the conditions of time. The causality of reason in its intelligible character does not begin to be; it does not

make its appearance at a certain time, for the purpose of producing an effect. If this were not the case, the

causality of reason would be subservient to the natural law of phenomena, which determines them according

to time, and as a series of causes and effects in time; it would consequently cease to be freedom and become a

part of nature. We are therefore justified in saying: "If reason stands in a causal relation to phenomena, it is a

faculty which originates the sensuous condition of an empirical series of effects." For the condition, which

resides in the reason, is nonsensuous, and therefore cannot be originated, or begin to be. And thus we find

what we could not discover in any empirical series a condition of a successive series of events itself

empirically unconditioned. For, in the present case, the condition stands out of and beyond the series of

phenomena it is intelligible, and it consequently cannot be subjected to any sensuous condition, or to any

*The real morality of actions their merit or demerit, and even that of our own conduct, is completely

unknown to us. Our estimates can relate only to their empirical character. How much is the result of the

action of free will, how much is to be ascribed to nature and to blameless error, or to a happy constitution of

temperament (merito fortunae), no one can discover, nor, for this reason, determine with perfect justice.

But, in another respect, the same cause belongs also to the series of phenomena. Man is himself a

phenomenon. His will has an empirical character, which is the empirical cause of all his actions. There is no

condition determining man and his volition in conformity with this character which does not itself form

part of the series of effects in nature, and is subject to their law the law according to which an empirically

undetermined cause of an event in time cannot exist. For this reason no given action can have an absolute and

spontaneous origination, all actions being phenomena, and belonging to the world of experience. But it

cannot be said of reason, that the state in which it determines the will is always preceded by some other state

determining it. For reason is not a phenomenon, and therefore not subject to sensuous conditions; and,

consequently, even in relation to its causality, the sequence or conditions of time do not influence reason, nor

can the dynamical law of nature, which determines the sequence of time according to certain rules, be applied

Reason is consequently the permanent condition of all actions of the human will. Each of these is determined

in the empirical character of the man, even before it has taken place. The intelligible character, of which the

former is but the sensuous schema, knows no before or after; and every action, irrespective of the

timerelation in which it stands with other phenomena, is the immediate effect of the intelligible character of

pure reason, which, consequently, enjoys freedom of action, and is not dynamically determined either by

internal or external preceding conditions. This freedom must not be described, in a merely negative manner,

as independence of empirical conditions, for in this case the faculty of reason would cease to be a cause of

phenomena; but it must be regarded, positively, as a faculty which can spontaneously originate a series of

events. At the same time, it must not be supposed that any beginning can take place in reason; on the

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contrary, reason, as the unconditioned condition of all action of the will, admits of no timeconditions,

although its effect does really begin in a series of phenomena a beginning which is not, however, absolutely

I shall illustrate this regulative principle of reason by an example, from its employment in the world of

experience; proved it cannot be by any amount of experience, or by any number of facts, for such arguments

cannot establish the truth of transcendental propositions. Let us take a voluntary action for example, a

falsehood by means of which a man has introduced a certain degree of confusion into the social life of

humanity, which is judged according to the motives from which it originated, and the blame of which and of

the evil consequences arising from it, is imputed to the offender. We at first proceed to examine the empirical

character of the offence, and for this purpose we endeavour to penetrate to the sources of that character, such

as a defective education, bad company, a shameless and wicked disposition, frivolity, and want of reflection

not forgetting also the occasioning causes which prevailed at the moment of the transgression. In this the

procedure is exactly the same as that pursued in the investigation of the series of causes which determine a

given physical effect. Now, although we believe the action to have been determined by all these

circumstances, we do not the less blame the offender. We do not blame him for his unhappy disposition, nor

for the circumstances which influenced him, nay, not even for his former course of life; for we presuppose

that all these considerations may be set aside, that the series of preceding conditions may be regarded as

having never existed, and that the action may be considered as completely unconditioned in relation to any

state preceding, just as if the agent commenced with it an entirely new series of effects. Our blame of the

offender is grounded upon a law of reason, which requires us to regard this faculty as a cause, which could

have and ought to have otherwise determined the behaviour of the culprit, independently of all empirical

conditions. This causality of reason we do not regard as a cooperating agency, but as complete in itself. It

matters not whether the sensuous impulses favoured or opposed the action of this causality, the offence is

estimated according to its intelligible character the offender is decidedly worthy of blame, the moment he

utters a falsehood. It follows that we regard reason, in spite of the empirical conditions of the act, as

The above judgement is complete evidence that we are accustomed to think that reason is not affected by

sensuous conditions, that in it no change takes place although its phenomena, in other words, the mode in

which it appears in its effects, are subject to change that in it no preceding state determines the following,

and, consequently, that it does not form a member of the series of sensuous conditions which necessitate

phenomena according to natural laws. Reason is present and the same in all human actions and at all times;

but it does not itself exist in time, and therefore does not enter upon any state in which it did not formerly

exist. It is, relatively to new states or conditions, determining, but not determinable. Hence we cannot ask:

"Why did not reason determine itself in a different manner?" The question ought to be thus stated: "Why did

not reason employ its power of causality to determine certain phenomena in a different manner?" "But this is

a question which admits of no answer. For a different intelligible character would have exhibited a different

empirical character; and, when we say that, in spite of the course which his whole former life has taken, the

offender could have refrained from uttering the falsehood, this means merely that the act was subject to the

power and authority permissive or prohibitive of reason. Now, reason is not subject in its causality to any

conditions of phenomena or of time; and a difference in time may produce a difference in the relation of

phenomena to each other for these are not things and therefore not causes in themselves but it cannot

produce any difference in the relation in which the action stands to the faculty of reason.

Thus, then, in our investigation into free actions and the causal power which produced them, we arrive at an

intelligible cause, beyond which, however, we cannot go; although we can recognize that it is free, that is,

independent of all sensuous conditions, and that, in this way, it may be the sensuously unconditioned

condition of phenomena. But for what reason the intelligible character generates such and such phenomena

and exhibits such and such an empirical character under certain circumstances, it is beyond the power of our

reason to decide. The question is as much above the power and the sphere of reason as the following would

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be: "Why does the transcendental object of our external sensuous intuition allow of no other form than that of

intuition in space?" But the problem, which we were called upon to solve, does not require us to entertain any

such questions. The problem was merely this whether freedom and natural necessity can exist without

opposition in the same action. To this question we have given a sufficient answer; for we have shown that, as

the former stands in a relation to a different kind of condition from those of the latter, the law of the one does

not affect the law of the other and that, consequently, both can exist together in independence of and without

The reader must be careful to remark that my intention in the above remarks has not been to prove the actual

existence of freedom, as a faculty in which resides the cause of certain sensuous phenomena. For, not to

mention that such an argument would not have a transcendental character, nor have been limited to the

discussion of pure conceptions all attempts at inferring from experience what cannot be cogitated in

accordance with its laws, must ever be unsuccessful. Nay, more, I have not even aimed at demonstrating the

possibility of freedom; for this too would have been a vain endeavour, inasmuch as it is beyond the power of

the mind to cognize the possibility of a reality or of a causal power by the aid of mere a priori conceptions.

Freedom has been considered in the foregoing remarks only as a transcendental idea, by means of which

reason aims at originating a series of conditions in the world of phenomena with the help of that which is

sensuously unconditioned, involving itself, however, in an antinomy with the laws which itself prescribes for

the conduct of the understanding. That this antinomy is based upon a mere illusion, and that nature and

freedom are at least not opposed this was the only thing in our power to prove, and the question which it

In the preceding remarks, we considered the changes in the world of sense as constituting a dynamical series,

in which each member is subordinated to another as its cause. Our present purpose is to avail ourselves of

this series of states or conditions as a guide to an existence which may be the highest condition of all

changeable phenomena, that is, to a necessary being. Our endeavour to reach, not the unconditioned

causality, but the unconditioned existence, of substance. The series before us is therefore a series of

conceptions, and not of intuitions (in which the one intuition is the condition of the other).

But it is evident that, as all phenomena are subject to change and conditioned in their existence, the series of

dependent existences cannot embrace an unconditioned member, the existence of which would be absolutely

necessary. It follows that, if phenomena were things in themselves, and as an immediate consequence from

this supposition condition and conditioned belonged to the same series of phenomena, the existence of a

necessary being, as the condition of the existence of sensuous phenomena, would be perfectly impossible.

An important distinction, however, exists between the dynamical and the mathematical regress. The latter is

engaged solely with the combination of parts into a whole, or with the division of a whole into its parts; and

therefore are the conditions of its series parts of the series, and to be consequently regarded as homogeneous,

and for this reason, as consisting, without exception, of phenomena. If the former regress, on the contrary, the

aim of which is not to establish the possibility of an unconditioned whole consisting of given parts, or of an

unconditioned part of a given whole, but to demonstrate the possibility of the deduction of a certain state

from its cause, or of the contingent existence of substance from that which exists necessarily, it is not

requisite that the condition should form part of an empirical series along with the conditioned.

In the case of the apparent antinomy with which we are at present dealing, there exists a way of escape from

the difficulty; for it is not impossible that both of the contradictory statements may be true in different

relations. All sensuous phenomena may be contingent, and consequently possess only an empirically

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conditioned existence, and yet there may also exist a nonempirical condition of the whole series, or, in other

words, a necessary being. For this necessary being, as an intelligible condition, would not form a member

not even the highest member of the series; the whole world of sense would be left in its empirically

determined existence uninterfered with and uninfluenced. This would also form a ground of distinction

between the modes of solution employed for the third and fourth antinomies. For, while in the consideration

of freedom in the former antinomy, the thing itself the cause (substantia phaenomenon) was regarded as

belonging to the series of conditions, and only its causality to the intelligible world we are obliged in the

present case to cogitate this necessary being as purely intelligible and as existing entirely apart from the

world of sense (as an ens extramundanum); for otherwise it would be subject to the phenomenal law of

In relation to the present problem, therefore, the regulative principle of reason is that everything in the

sensuous world possesses an empirically conditioned existence that no property of the sensuous world

possesses unconditioned necessity that we are bound to expect, and, so far as is possible, to seek for the

empirical condition of every member in the series of conditions and that there is no sufficient reason to

justify us in deducing any existence from a condition which lies out of and beyond the empirical series, or in

regarding any existence as independent and selfsubsistent; although this should not prevent us from

recognizing the possibility of the whole series being based upon a being which is intelligible, and for this

But it has been far from my intention, in these remarks, to prove the existence of this unconditioned and

necessary being, or even to evidence the possibility of a purely intelligible condition of the existence or all

sensuous phenomena. As bounds were set to reason, to prevent it from leaving the guiding thread of empirical

conditions and losing itself in transcendent theories which are incapable of concrete presentation; so it was

my purpose, on the other band, to set bounds to the law of the purely empirical understanding, and to protest

against any attempts on its part at deciding on the possibility of things, or declaring the existence of the

intelligible to be impossible, merely on the ground that it is not available for the explanation and exposition

of phenomena. It has been shown, at the same time, that the contingency of all the phenomena of nature and

their empirical conditions is quite consistent with the arbitrary hypothesis of a necessary, although purely

intelligible condition, that no real contradiction exists between them and that, consequently, both may be true.

The existence of such an absolutely necessary being may be impossible; but this can never be demonstrated

from the universal contingency and dependence of sensuous phenomena, nor from the principle which forbids

us to discontinue the series at some member of it, or to seek for its cause in some sphere of existence beyond

the world of nature. Reason goes its way in the empirical world, and follows, too, its peculiar path in the

The sensuous world contains nothing but phenomena, which are mere representations, and always sensuously

conditioned; things in themselves are not, and cannot be, objects to us. It is not to be wondered at, therefore,

that we are not justified in leaping from some member of an empirical series beyond the world of sense, as if

empirical representations were things in themselves, existing apart from their transcendental ground in the

human mind, and the cause of whose existence may be sought out of the empirical series. This would

certainly be the case with contingent things; but it cannot be with mere representations of things, the

contingency of which is itself merely a phenomenon and can relate to no other regress than that which

determines phenomena, that is, the empirical. But to cogitate an intelligible ground of phenomena, as free,

moreover, from the contingency of the latter, conflicts neither with the unlimited nature of the empirical

regress, nor with the complete contingency of phenomena. And the demonstration of this was the only thing

necessary for the solution of this apparent antinomy. For if the condition of every conditioned as regards its

existence is sensuous, and for this reason a part of the same series, it must be itself conditioned, as was

shown in the antithesis of the fourth antinomy. The embarrassments into which a reason, which postulates the

unconditioned, necessarily falls, must, therefore, continue to exist; or the unconditioned must be placed in the

sphere of the intelligible. In this way, its necessity does not require, nor does it even permit, the presence of

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The empirical employment of reason is not affected by the assumption of a purely intelligible being; it

continues its operations on the principle of the contingency of all phenomena, proceeding from empirical

conditions to still higher and higher conditions, themselves empirical. just as little does this regulative

principle exclude the assumption of an intelligible cause, when the question regards merely the pure

employment of reason in relation to ends or aims. For, in this case, an intelligible cause signifies merely the

transcendental and to us unknown ground of the possibility of sensuous phenomena, and its existence,

necessary and independent of all sensuous conditions, is not inconsistent with the contingency of phenomena,

or with the unlimited possibility of regress which exists in the series of empirical conditions.

So long as the object of our rational conceptions is the totality of conditions in the world of phenomena, and

the satisfaction, from this source, of the requirements of reason, so long are our ideas transcendental and

cosmological. But when we set the unconditioned which is the aim of all our inquiries in a sphere which

lies out of the world of sense and possible experience, our ideas become transcendent. They are then not

merely serviceable towards the completion of the exercise of reason (which remains an idea, never executed,

but always to be pursued); they detach themselves completely from experience and construct for themselves

objects, the material of which has not been presented by experience, and the objective reality of which is not

based upon the completion of the empirical series, but upon pure a priori conceptions. The intelligible object

of these transcendent ideas may be conceded, as a transcendental object. But we cannot cogitate it as a thing

determinable by certain distinct predicates relating to its internal nature, for it has no connection with

empirical conceptions; nor are we justified in affirming the existence of any such object. It is, consequently, a

mere product of the mind alone. Of all the cosmological ideas, however, it is that occasioning the fourth

antinomy which compels us to venture upon this step. For the existence of phenomena, always conditioned

and never selfsubsistent, requires us to look for an object different from phenomena an intelligible object,

with which all contingency must cease. But, as we have allowed ourselves to assume the existence of a

selfsubsistent reality out of the field of experience, and are therefore obliged to regard phenomena as merely

a contingent mode of representing intelligible objects employed by beings which are themselves

intelligences no other course remains for us than to follow an alogy and employ the same mode in forming

some conception of intelligible things, of which we have not the least knowledge, which nature taught us to

use in the formation of empirical conceptions. Experience made us acquainted with the contingent. But we

are at present engaged in the discussion of things which are not objects of experience; and must, therefore,

deduce our knowledge of them from that which is necessary absolutely and in itself, that is, from pure

conceptions. Hence the first step which we take out of the world of sense obliges us to begin our system of

new cognition with the investigation of a necessary being, and to deduce from our conceptions of it all our

conceptions of intelligible things. This we propose to attempt in the following chapter.

We have seen that pure conceptions do not present objects to the mind, except under sensuous conditions;

because the conditions of objective reality do not exist in these conceptions, which contain, in fact, nothing

but the mere form of thought. They may, however, when applied to phenomena, be presented in concreto; for

it is phenomena that present to them the materials for the formation of empirical conceptions, which are

nothing more than concrete forms of the conceptions of the understanding. But ideas are still further removed

from objective reality than categories; for no phenomenon can ever present them to the human mind in

concreto. They contain a certain perfection, attainable by no possible empirical cognition; and they give to

reason a systematic unity, to which the unity of experience attempts to approximate, but can never completely

But still further removed than the idea from objective reality is the Ideal, by which term I understand the idea,

not in concreto, but in individuo as an individual thing, determinable or determined by the idea alone. The

idea of humanity in its complete perfection supposes not only the advancement of all the powers and

faculties, which constitute our conception of human nature, to a complete attainment of their final aims, but

also everything which is requisite for the complete determination of the idea; for of all contradictory

predicates, only one can conform with the idea of the perfect man. What I have termed an ideal was in Plato's

philosophy an idea of the divine mind an individual object present to its pure intuition, the most perfect of

Without rising to these speculative heights, we are bound to confess that human reason contains not only

ideas, but ideals, which possess, not, like those of Plato, creative, but certainly practical power as regulative

principles, and form the basis of the perfectibility of certain actions. Moral conceptions are not perfectly pure

conceptions of reason, because an empirical element of pleasure or pain lies at the foundation of them. In

relation, however, to the principle, whereby reason sets bounds to a freedom which is in itself without law,

and consequently when we attend merely to their form, they may be considered as pure conceptions of

reason. Virtue and wisdom in their perfect purity are ideas. But the wise man of the Stoics is an ideal, that is

to say, a human being existing only in thought and in complete conformity with the idea of wisdom. As the

idea provides a rule, so the ideal serves as an archetype for the perfect and complete determination of the

copy. Thus the conduct of this wise and divine man serves us as a standard of action, with which we may

compare and judge ourselves, which may help us to reform ourselves, although the perfection it demands can

never be attained by us. Although we cannot concede objective reality to these ideals, they are not to be

considered as chimeras; on the contrary, they provide reason with a standard, which enables it to estimate, by

comparison, the degree of incompleteness in the objects presented to it. But to aim at realizing the ideal in an

example in the world of experience to describe, for instance, the character of the perfectly wise man in a

romance is impracticable. Nay more, there is something absurd in the attempt; and the result must be little

edifying, as the natural limitations, which are continually breaking in upon the perfection and completeness

of the idea, destroy the illusion in the story and throw an air of suspicion even on what is good in the idea,

Such is the constitution of the ideal of reason, which is always based upon determinate conceptions, and

serves as a rule and a model for limitation or of criticism. Very different is the nature of the ideals of the

imagination. Of these it is impossible to present an intelligible conception; they are a kind of monogram,

drawn according to no determinate rule, and forming rather a vague picture the production of many diverse

experiences than a determinate image. Such are the ideals which painters and physiognomists profess to

have in their minds, and which can serve neither as a model for production nor as a standard for appreciation.

They may be termed, though improperly, sensuous ideals, as they are declared to be models of certain

possible empirical intuitions. They cannot, however, furnish rules or standards for explanation or examination

In its ideals, reason aims at complete and perfect determination according to a priori rules; and hence it

cogitates an object, which must be completely determinable in conformity with principles, although all

empirical conditions are absent, and the conception of the object is on this account transcendent.

Every conception is, in relation to that which is not contained in it, undetermined and subject to the principle

of determinability. This principle is that, of every two contradictorily opposed predicates, only one can

belong to a conception. It is a purely logical principle, itself based upon the principle of contradiction;

inasmuch as it makes complete abstraction of the content and attends merely to the logical form of the

But again, everything, as regards its possibility, is also subject to the principle of complete determination,

according to which one of all the possible contradictory predicates of things must belong to it. This principle

is not based merely upon that of contradiction; for, in addition to the relation between two contradictory

predicates, it regards everything as standing in a relation to the sum of possibilities, as the sum total of all

predicates of things, and, while presupposing this sum as an a priori condition, presents to the mind

everything as receiving the possibility of its individual existence from the relation it bears to, and the share it

possesses in, the aforesaid sum of possibilities.* The principle of complete determination relates the content

and not to the logical form. It is the principle of the synthesis of all the predicates which are required to

constitute the complete conception of a thing, and not a mere principle analytical representation, which

enounces that one of two contradictory predicates must belong to a conception. It contains, moreover, a

transcendental presupposition that, namely, of the material for all possibility, which must contain a priori

*Thus this principle declares everything to possess a relation to a common correlate the sumtotal of

possibility, which, if discovered to exist in the idea of one individual thing, would establish the affinity of all

possible things, from the identity of the ground of their complete determination. The determinability of every

conception is subordinate to the universality (Allgemeinheit, universalitas) of the principle of excluded

middle; the determination of a thing to the totality (Allheit, universitas) of all possible predicates.

The proposition, Everything which exists is completely determined, means not only that one of every pair of

given contradictory attributes, but that one of all possible attributes, is always predicable of the thing; in it the

predicates are not merely compared logically with each other, but the thing itself is transcendentally

compared with the sumtotal of all possible predicates. The proposition is equivalent to saying: "To attain to

a complete knowledge of a thing, it is necessary to possess a knowledge of everything that is possible, and to

determine it thereby in a positive or negative manner." The conception of complete determination is

consequently a conception which cannot be presented in its totality in concreto, and is therefore based upon

an idea, which has its seat in the reason the faculty which prescribes to the understanding the laws of its

Now, although this idea of the sumtotal of all possibility, in so far as it forms the condition of the complete

determination of everything, is itself undetermined in relation to the predicates which may constitute this

sumtotal, and we cogitate in it merely the sumtotal of all possible predicates we nevertheless find, upon

closer examination, that this idea, as a primitive conception of the mind, excludes a large number of

predicates those deduced and those irreconcilable with others, and that it is evolved as a conception

completely determined a priori. Thus it becomes the conception of an individual object, which is completely

determined by and through the mere idea, and must consequently be termed an ideal of pure reason.

When we consider all possible predicates, not merely logically, but transcendentally, that is to say, with

reference to the content which may be cogitated as existing in them a priori, we shall find that some indicate a

being, others merely a nonbeing. The logical negation expressed in the word not does not properly belong to

a conception, but only to the relation of one conception to another in a judgement, and is consequently quite

insufficient to present to the mind the content of a conception. The expression not mortal does not indicate

that a nonbeing is cogitated in the object; it does not concern the content at all. A transcendental negation,

on the contrary, indicates nonbeing in itself, and is opposed to transcendental affirmation, the conception of

which of itself expresses a being. Hence this affirmation indicates a reality, because in and through it objects

are considered to be something to be things; while the opposite negation, on the other band, indicates a mere

want, or privation, or absence, and, where such negations alone are attached to a representation, the

Now a negation cannot be cogitated as determined, without cogitating at the same time the opposite

affirmation. The man born blind has not the least notion of darkness, because he has none of light; the

vagabond knows nothing of poverty, because he has never known what it is to be in comfort;* the ignorant

man has no conception of his ignorance, because he has no conception of knowledge. All conceptions of

negatives are accordingly derived or deduced conceptions; and realities contain the data, and, so to speak, the

material or transcendental content of the possibility and complete determination of all things.

*The investigations and calculations of astronomers have taught us much that is wonderful; but the most

important lesson we have received from them is the discovery of the abyss of our ignorance in relation to the

universe an ignorance the magnitude of which reason, without the information thus derived, could never

have conceived. This discovery of our deficiencies must produce a great change in the determination of the

If, therefore, a transcendental substratum lies at the foundation of the complete determination of things a

substratum which is to form the fund from which all possible predicates of things are to be supplied, this

substratum cannot be anything else than the idea of a sumtotal of reality (omnitudo realitatis). In this view,

negations are nothing but limitations a term which could not, with propriety, be applied to them, if the

This conception of a sumtotal of reality is the conception of a thing in itself, regarded as completely

determined; and the conception of an ens realissimum is the conception of an individual being, inasmuch as it

is determined by that predicate of all possible contradictory predicates, which indicates and belongs to being.

It is, therefore, a transcendental ideal which forms the basis of the complete determination of everything that

exists, and is the highest material condition of its possibility a condition on which must rest the cogitation of

all objects with respect to their content. Nay, more, this ideal is the only proper ideal of which the human

mind is capable; because in this case alone a general conception of a thing is completely determined by and

The logical determination of a conception is based upon a disjunctive syllogism, the major of which contains

the logical division of the extent of a general conception, the minor limits this extent to a certain part, while

the conclusion determines the conception by this part. The general conception of a reality cannot be divided a

priori, because, without the aid of experience, we cannot know any determinate kinds of reality, standing

under the former as the genus. The transcendental principle of the complete determination of all things is

therefore merely the representation of the sumtotal of all reality; it is not a conception which is the genus of

all predicates under itself, but one which comprehends them all within itself. The complete determination of a

thing is consequently based upon the limitation of this total of reality, so much being predicated of the thing,

while all that remains over is excluded a procedure which is in exact agreement with that of the disjunctive

syllogism and the determination of the objects in the conclusion by one of the members of the division. It

follows that reason, in laying the transcendental ideal at the foundation of its determination of all possible

things, takes a course in exact analogy with that which it pursues in disjunctive syllogisms a proposition

which formed the basis of the systematic division of all transcendental ideas, according to which they are

produced in complete parallelism with the three modes of syllogistic reasoning employed by the human mind.

It is selfevident that reason, in cogitating the necessary complete determination of things, does not

presuppose the existence of a being corresponding to its ideal, but merely the idea of the ideal for the

purpose of deducing from the unconditional totality of complete determination, The ideal is therefore the

prototype of all things, which, as defective copies (ectypa), receive from it the material of their possibility,

and approximate to it more or less, though it is impossible that they can ever attain to its perfection.

The possibility of things must therefore be regarded as derived except that of the thing which contains in

itself all reality, which must be considered to be primitive and original. For all negations and they are the

only predicates by means of which all other things can be distinguished from the ens realissimum are mere

limitations of a greater and a higher nay, the highest reality; and they consequently presuppose this reality,

and are, as regards their content, derived from it. The manifold nature of things is only an infinitely various

mode of limiting the conception of the highest reality, which is their common substratum; just as all figures

are possible only as different modes of limiting infinite space. The object of the ideal of reason an object

existing only in reason itself is also termed the primal being (ens originarium); as having no existence

superior to him, the supreme being (ens summum); and as being the condition of all other beings, which rank

under it, the being of all beings (ens entium). But none of these terms indicate the objective relation of an

actually existing object to other things, but merely that of an idea to conceptions; and all our investigations

into this subject still leave us in perfect uncertainty with regard to the existence of this being.

A primal being cannot be said to consist of many other beings with an existence which is derivative, for the

latter presuppose the former, and therefore cannot be constitutive parts of it. It follows that the ideal of the

The deduction of the possibility of all other things from this primal being cannot, strictly speaking, be

considered as a limitation, or as a kind of division of its reality; for this would be regarding the primal being

as a mere aggregate which has been shown to be impossible, although it was so represented in our first

rough sketch. The highest reality must be regarded rather as the ground than as the sumtotal of the

possibility of all things, and the manifold nature of things be based, not upon the limitation of the primal

being itself, but upon the complete series of effects which flow from it. And thus all our powers of sense, as

well as all phenomenal reality, phenomenal reality, may be with propriety regarded as belonging to this series

of effects, while they could not have formed parts of the idea, considered as an aggregate. Pursuing this track,

and hypostatizing this idea, we shall find ourselves authorized to determine our notion of the Supreme Being

by means of the mere conception of a highest reality, as one, simple, allsufficient, eternal, and so on in one

word, to determine it in its unconditioned completeness by the aid of every possible predicate. The

conception of such a being is the conception of God in its transcendental sense, and thus the ideal of pure

But, by such an employment of the transcendental idea, we should be over stepping the limits of its validity

and purpose. For reason placed it, as the conception of all reality, at the basis of the complete determination

of things, without requiring that this conception be regarded as the conception of an objective existence. Such

an existence would be purely fictitious, and the hypostatizing of the content of the idea into an ideal, as an

individual being, is a step perfectly unauthorized. Nay, more, we are not even called upon to assume the

possibility of such an hypothesis, as none of the deductions drawn from such an ideal would affect the

complete determination of things in general for the sake of which alone is the idea necessary.

It is not sufficient to circumscribe the procedure and the dialectic of reason; we must also endeavour to

discover the sources of this dialectic, that we may have it in our power to give a rational explanation of this

illusion, as a phenomenon of the human mind. For the ideal, of which we are at present speaking, is based,

not upon an arbitrary, but upon a natural, idea. The question hence arises: How happens it that reason regards

the possibility of all things as deduced from a single possibility, that, to wit, of the highest reality, and

The answer is ready; it is at once presented by the procedure of transcendental analytic. The possibility of

sensuous objects is a relation of these objects to thought, in which something (the empirical form) may be

cogitated a priori; while that which constitutes the matter the reality of the phenomenon (that element which

corresponds to sensation) must be given from without, as otherwise it could not even be cogitated by, nor

could its possibility be presentable to the mind. Now, a sensuous object is completely determined, when it has

been compared with all phenomenal predicates, and represented by means of these either positively or

negatively. But, as that which constitutes the thing itself the real in a phenomenon, must be given, and that,

in which the real of all phenomena is given, is experience, one, sole, and allembracing the material of the

possibility of all sensuous objects must be presupposed as given in a whole, and it is upon the limitation of

this whole that the possibility of all empirical objects, their distinction from each other and their complete

determination, are based. Now, no other objects are presented to us besides sensuous objects, and these can

be given only in connection with a possible experience; it follows that a thing is not an object to us, unless it

presupposes the whole or sumtotal of empirical reality as the condition of its possibility. Now, a natural

illusion leads us to consider this principle, which is valid only of sensuous objects, as valid with regard to

things in general. And thus we are induced to hold the empirical principle of our conceptions of the

possibility of things, as phenomena, by leaving out this limitative condition, to be a transcendental principle

We proceed afterwards to hypostatize this idea of the sumtotal of all reality, by changing the distributive

unity of the empirical exercise of the understanding into the collective unity of an empirical whole a

dialectical illusion, and by cogitating this whole or sum of experience as an individual thing, containing in

itself all empirical reality. This individual thing or being is then, by means of the abovementioned

transcendental subreption, substituted for our notion of a thing which stands at the head of the possibility of

*This ideal of the ens realissimum although merely a mental representation is first objectivized, that is, has

an objective existence attributed to it, then hypostatized, and finally, by the natural progress of reason to the

completion of unity, personified, as we shall show presently. For the regulative unity of experience is not

based upon phenomena themselves, but upon the connection of the variety of phenomena by the

understanding in a consciousness, and thus the unity of the supreme reality and the complete determinability

of all things, seem to reside in a supreme understanding, and, consequently, in a conscious intelligence.

Notwithstanding the pressing necessity which reason feels, to form some presupposition that shall serve the

understanding as a proper basis for the complete determination of its conceptions, the idealistic and factitious

nature of such a presupposition is too evident to allow reason for a moment to persuade itself into a belief of

the objective existence of a mere creation of its own thought. But there are other considerations which

compel reason to seek out some resting place in the regress from the conditioned to the unconditioned, which

is not given as an actual existence from the mere conception of it, although it alone can give completeness to

the series of conditions. And this is the natural course of every human reason, even of the most uneducated,

although the path at first entered it does not always continue to follow. It does not begin from conceptions,

but from common experience, and requires a basis in actual existence. But this basis is insecure, unless it

rests upon the immovable rock of the absolutely necessary. And this foundation is itself unworthy of trust, if

it leave under and above it empty space, if it do not fill all, and leave no room for a why or a wherefore, if it

If we admit the existence of some one thing, whatever it may be, we must also admit that there is something

which exists necessarily. For what is contingent exists only under the condition of some other thing, which is

its cause; and from this we must go on to conclude the existence of a cause which is not contingent, and

which consequently exists necessarily and unconditionally. Such is the argument by which reason justifies its

Now reason looks round for the conception of a being that may be admitted, without inconsistency, to be

worthy of the attribute of absolute necessity, not for the purpose of inferring a priori, from the conception of

such a being, its objective existence (for if reason allowed itself to take this course, it would not require a

SECTION III. Of the Arguments employed by Speculative Reason in Proof of the Existence of a Supreme Being. 194

basis in given and actual existence, but merely the support of pure conceptions), but for the purpose of

discovering, among all our conceptions of possible things, that conception which possesses no element

inconsistent with the idea of absolute necessity. For that there must be some absolutely necessary existence, it

regards as a truth already established. Now, if it can remove every existence incapable of supporting the

attribute of absolute necessity, excepting one this must be the absolutely necessary being, whether its

necessity is comprehensible by us, that is, deducible from the conception of it alone, or not.

Now that, the conception of which contains a therefore to every wherefore, which is not defective in any

respect whatever, which is allsufficient as a condition, seems to be the being of which we can justly

predicate absolute necessity for this reason, that, possessing the conditions of all that is possible, it does not

and cannot itself require any condition. And thus it satisfies, in one respect at least, the requirements of the

conception of absolute necessity. In this view, it is superior to all other conceptions, which, as deficient and

incomplete, do not possess the characteristic of independence of all higher conditions. It is true that we

cannot infer from this that what does not contain in itself the supreme and complete condition the condition

of all other things must possess only a conditioned existence; but as little can we assert the contrary, for this

supposed being does not possess the only characteristic which can enable reason to cognize by means of an a

The conception of an ens realissimum is that which best agrees with the conception of an unconditioned and

necessary being. The former conception does not satisfy all the requirements of the latter; but we have no

choice, we are obliged to adhere to it, for we find that we cannot do without the existence of a necessary

being; and even although we admit it, we find it out of our power to discover in the whole sphere of

possibility any being that can advance wellgrounded claims to such a distinction.

The following is, therefore, the natural course of human reason. It begins by persuading itself of the existence

of some necessary being. In this being it recognizes the characteristics of unconditioned existence. It then

seeks the conception of that which is independent of all conditions, and finds it in that which is itself the

sufficient condition of all other things in other words, in that which contains all reality. But the unlimited all

is an absolute unity, and is conceived by the mind as a being one and supreme; and thus reason concludes that

the Supreme Being, as the primal basis of all things, possesses an existence which is absolutely necessary.

This conception must be regarded as in some degree satisfactory, if we admit the existence of a necessary

being, and consider that there exists a necessity for a definite and final answer to these questions. In such a

case, we cannot make a better choice, or rather we have no choice at all, but feel ourselves obliged to declare

in favour of the absolute unity of complete reality, as the highest source of the possibility of things. But if

there exists no motive for coming to a definite conclusion, and we may leave the question unanswered till we

have fully weighed both sides in other words, when we are merely called upon to decide how much we

happen to know about the question, and how much we merely flatter ourselves that we know the above

conclusion does not appear to be so great advantage, but, on the contrary, seems defective in the grounds

For, admitting the truth of all that has been said, that, namely, the inference from a given existence (my own,

for example) to the existence of an unconditioned and necessary being is valid and unassailable; that, in the

second place, we must consider a being which contains all reality, and consequently all the conditions of

other things, to be absolutely unconditioned; and admitting too, that we have thus discovered the conception

of a thing to which may be attributed, without inconsistency, absolute necessity it does not follow from all

this that the conception of a limited being, in which the supreme reality does not reside, is therefore

incompatible with the idea of absolute necessity. For, although I do not discover the element of the

unconditioned in the conception of such a being an element which is manifestly existent in the sumtotal of

all conditions I am not entitled to conclude that its existence is therefore conditioned; just as I am not

entitled to affirm, in a hypothetical syllogism, that where a certain condition does not exist (in the present,

SECTION III. Of the Arguments employed by Speculative Reason in Proof of the Existence of a Supreme Being. 195

completeness, as far as pure conceptions are concerned), the conditioned does not exist either. On the

contrary, we are free to consider all limited beings as likewise unconditionally necessary, although we are

unable to infer this from the general conception which we have of them. Thus conducted, this argument is

incapable of giving us the least notion of the properties of a necessary being, and must be in every respect

This argument continues, however, to possess a weight and an authority, which, in spite of its objective

insufficiency, it has never been divested of. For, granting that certain responsibilities lie upon us, which, as

based on the ideas of reason, deserve to be respected and submitted to, although they are incapable of a real

or practical application to our nature, or, in other words, would be responsibilities without motives, except

upon the supposition of a Supreme Being to give effect and influence to the practical laws: in such a case we

should be bound to obey our conceptions, which, although objectively insufficient, do, according to the

standard of reason, preponderate over and are superior to any claims that may be advanced from any other

quarter. The equilibrium of doubt would in this case be destroyed by a practical addition; indeed, Reason

would be compelled to condemn herself, if she refused to comply with the demands of the judgement, no

superior to which we know however defective her understanding of the grounds of these demands might be.

This argument, although in fact transcendental, inasmuch as it rests upon the intrinsic insufficiency of the

contingent, is so simple and natural, that the commonest understanding can appreciate its value. We see

things around us change, arise, and pass away; they, or their condition, must therefore have a cause. The same

demand must again be made of the cause itself as a datum of experience. Now it is natural that we should

place the highest causality just where we place supreme causality, in that being, which contains the

conditions of all possible effects, and the conception of which is so simple as that of an allembracing reality.

This highest cause, then, we regard as absolutely necessary, because we find it absolutely necessary to rise to

it, and do not discover any reason for proceeding beyond it. Thus, among all nations, through the darkest

polytheism glimmer some faint sparks of monotheism, to which these idolaters have been led, not from

reflection and profound thought, but by the study and natural progress of the common understanding.

There are only three modes of proving the existence of a Deity, on the grounds of speculative reason.

All the paths conducting to this end begin either from determinate experience and the peculiar constitution of

the world of sense, and rise, according to the laws of causality, from it to the highest cause existing apart

from the world or from a purely indeterminate experience, that is, some empirical existence or abstraction

is made of all experience, and the existence of a supreme cause is concluded from a priori conceptions alone.

The first is the physicotheological argument, the second the cosmological, the third the ontological. More

I shall show it is as unsuccessful on the one path the empirical as on the other the transcendental and

that it stretches its wings in vain, to soar beyond the world of sense by the mere might of speculative thought.

As regards the order in which we must discuss those arguments, it will be exactly the reverse of that in which

reason, in the progress of its development, attains to them the order in which they are placed above. For it

will be made manifest to the reader that, although experience presents the occasion and the startingpoint, it

is the transcendental idea of reason which guides it in its pilgrimage and is the goal of all its struggles. I shall

therefore begin with an examination of the transcendental argument, and afterwards inquire what additional

strength has accrued to this mode of proof from the addition of the empirical element.

SECTION IV. Of the Impossibility of an Ontological Proof of the Existence of God. 196

It is evident from what has been said that the conception of an absolutely necessary being is a mere idea, the

objective reality of which is far from being established by the mere fact that it is a need of reason. On the

contrary, this idea serves merely to indicate a certain unattainable perfection, and rather limits the operations

than, by the presentation of new objects, extends the sphere of the understanding. But a strange anomaly

meets us at the very threshold; for the inference from a given existence in general to an absolutely necessary

existence seems to be correct and unavoidable, while the conditions of the understanding refuse to aid us in

Philosophers have always talked of an absolutely necessary being, and have nevertheless declined to take the

trouble of conceiving whether and how a being of this nature is even cogitable, not to mention that its

existence is actually demonstrable. A verbal definition of the conception is certainly easy enough: it is

something the nonexistence of which is impossible. But does this definition throw any light upon the

conditions which render it impossible to cogitate the nonexistence of a thing conditions which we wish to

ascertain, that we may discover whether we think anything in the conception of such a being or not? For the

mere fact that I throw away, by means of the word unconditioned, all the conditions which the understanding

habitually requires in order to regard anything as necessary, is very far from making clear whether by means

of the conception of the unconditionally necessary I think of something, or really of nothing at all.

Nay, more, this chanceconception, now become so current, many have endeavoured to explain by examples

which seemed to render any inquiries regarding its intelligibility quite needless. Every geometrical

proposition a triangle has three angles it was said, is absolutely necessary; and thus people talked of an

object which lay out of the sphere of our understanding as if it were perfectly plain what the conception of

All the examples adduced have been drawn, without exception, from judgements, and not from things. But

the unconditioned necessity of a judgement does not form the absolute necessity of a thing. On the contrary,

the absolute necessity of a judgement is only a conditioned necessity of a thing, or of the predicate in a

judgement. The proposition abovementioned does not enounce that three angles necessarily exist, but, upon

condition that a triangle exists, three angles must necessarily exist in it. And thus this logical necessity has

been the source of the greatest delusions. Having formed an a priori conception of a thing, the content of

which was made to embrace existence, we believed ourselves safe in concluding that, because existence

belongs necessarily to the object of the conception (that is, under the condition of my positing this thing as

given), the existence of the thing is also posited necessarily, and that it is therefore absolutely necessary

If, in an identical judgement, I annihilate the predicate in thought, and retain the subject, a contradiction is the

result; and hence I say, the former belongs necessarily to the latter. But if I suppress both subject and

predicate in thought, no contradiction arises; for there is nothing at all, and therefore no means of forming a

contradiction. To suppose the existence of a triangle and not that of its three angles, is selfcontradictory; but

to suppose the nonexistence of both triangle and angles is perfectly admissible. And so is it with the

conception of an absolutely necessary being. Annihilate its existence in thought, and you annihilate the thing

itself with all its predicates; how then can there be any room for contradiction? Externally, there is nothing to

give rise to a contradiction, for a thing cannot be necessary externally; nor internally, for, by the annihilation

or suppression of the thing itself, its internal properties are also annihilated. God is omnipotent that is a

necessary judgement. His omnipotence cannot be denied, if the existence of a Deity is posited the existence,

that is, of an infinite being, the two conceptions being identical. But when you say, God does not exist,

neither omnipotence nor any other predicate is affirmed; they must all disappear with the subject, and in this

You have thus seen that when the predicate of a judgement is annihilated in thought along with the subject,

no internal contradiction can arise, be the predicate what it may. There is no possibility of evading the

SECTION IV. Of the Impossibility of an Ontological Proof of the Existence of God. 197

conclusion you find yourselves compelled to declare: There are certain subjects which cannot be annihilated

in thought. But this is nothing more than saying: There exist subjects which are absolutely necessary the

very hypothesis which you are called upon to establish. For I find myself unable to form the slightest

conception of a thing which when annihilated in thought with all its predicates, leaves behind a contradiction;

and contradiction is the only criterion of impossibility in the sphere of pure a priori conceptions.

Against these general considerations, the justice of which no one can dispute, one argument is adduced,

which is regarded as furnishing a satisfactory demonstration from the fact. It is affirmed that there is one and

only one conception, in which the nonbeing or annihilation of the object is selfcontradictory, and this is the

conception of an ens realissimum. It possesses, you say, all reality, and you feel yourselves justified in

admitting the possibility of such a being. (This I am willing to grant for the present, although the existence of

a conception which is not selfcontradictory is far from being sufficient to prove the possibility of an

object.)* Now the notion of all reality embraces in it that of existence; the notion of existence lies, therefore,

in the conception of this possible thing. If this thing is annihilated in thought, the internal possibility of the

*A conception is always possible, if it is not selfcontradictory. This is the logical criterion of possibility,

distinguishing the object of such a conception from the nihil negativum. But it may be, notwithstanding, an

empty conception, unless the objective reality of this synthesis, but which it is generated, is demonstrated;

and a proof of this kind must be based upon principles of possible experience, and not upon the principle of

analysis or contradiction. This remark may be serviceable as a warning against concluding, from the

possibility of a conception which is logical the possibility of a thing which is real.

I answer: It is absurd to introduce under whatever term disguised into the conception of a thing, which is to

be cogitated solely in reference to its possibility, the conception of its existence. If this is admitted, you will

have apparently gained the day, but in reality have enounced nothing but a mere tautology. I ask, is the

proposition, this or that thing (which I am admitting to be possible) exists, an analytical or a synthetical

proposition? If the former, there is no addition made to the subject of your thought by the affirmation of its

existence; but then the conception in your minds is identical with the thing itself, or you have supposed the

existence of a thing to be possible, and then inferred its existence from its internal possibility which is but a

miserable tautology. The word reality in the conception of the thing, and the word existence in the conception

of the predicate, will not help you out of the difficulty. For, supposing you were to term all positing of a thing

reality, you have thereby posited the thing with all its predicates in the conception of the subject and assumed

its actual existence, and this you merely repeat in the predicate. But if you confess, as every reasonable

person must, that every existential proposition is synthetical, how can it be maintained that the predicate of

existence cannot be denied without contradiction? a property which is the characteristic of analytical

I should have a reasonable hope of putting an end for ever to this sophistical mode of argumentation, by a

strict definition of the conception of existence, did not my own experience teach me that the illusion arising

from our confounding a logical with a real predicate (a predicate which aids in the determination of a thing)

resists almost all the endeavours of explanation and illustration. A logical predicate may be what you please,

even the subject may be predicated of itself; for logic pays no regard to the content of a judgement. But the

determination of a conception is a predicate, which adds to and enlarges the conception. It must not,

Being is evidently not a real predicate, that is, a conception of something which is added to the conception of

some other thing. It is merely the positing of a thing, or of certain determinations in it. Logically, it is merely

the copula of a judgement. The proposition, God is omnipotent, contains two conceptions, which have a

certain object or content; the word is, is no additional predicate it merely indicates the relation of the

predicate to the subject. Now, if I take the subject (God) with all its predicates (omnipotence being one), and

SECTION IV. Of the Impossibility of an Ontological Proof of the Existence of God. 198

say: God is, or, There is a God, I add no new predicate to the conception of God, I merely posit or affirm the

existence of the subject with all its predicates I posit the object in relation to my conception. The content of

both is the same; and there is no addition made to the conception, which expresses merely the possibility of

the object, by my cogitating the object in the expression, it is as absolutely given or existing. Thus the real

contains no more than the possible. A hundred real dollars contain no more than a hundred possible dollars.

For, as the latter indicate the conception, and the former the object, on the supposition that the content of the

former was greater than that of the latter, my conception would not be an expression of the whole object, and

would consequently be an inadequate conception of it. But in reckoning my wealth there may be said to be

more in a hundred real dollars than in a hundred possible dollars that is, in the mere conception of them. For

the real object the dollars is not analytically contained in my conception, but forms a synthetical addition

to my conception (which is merely a determination of my mental state), although this objective reality this

existence apart from my conceptions, does not in the least degree increase the aforesaid hundred dollars.

By whatever and by whatever number of predicates even to the complete determination of it I may cogitate

a thing, I do not in the least augment the object of my conception by the addition of the statement: This thing

exists. Otherwise, not exactly the same, but something more than what was cogitated in my conception,

would exist, and I could not affirm that the exact object of my conception had real existence. If I cogitate a

thing as containing all modes of reality except one, the mode of reality which is absent is not added to the

conception of the thing by the affirmation that the thing exists; on the contrary, the thing exists if it exist at

all with the same defect as that cogitated in its conception; otherwise not that which was cogitated, but

something different, exists. Now, if I cogitate a being as the highest reality, without defect or imperfection,

the question still remains whether this being exists or not? For, although no element is wanting in the

possible real content of my conception, there is a defect in its relation to my mental state, that is, I am

ignorant whether the cognition of the object indicated by the conception is possible a posteriori. And here the

cause of the present difficulty becomes apparent. If the question regarded an object of sense merely, it would

be impossible for me to confound the conception with the existence of a thing. For the conception merely

enables me to cogitate an object as according with the general conditions of experience; while the existence

of the object permits me to cogitate it as contained in the sphere of actual experience. At the same time, this

connection with the world of experience does not in the least augment the conception, although a possible

perception has been added to the experience of the mind. But if we cogitate existence by the pure category

alone, it is not to be wondered at, that we should find ourselves unable to present any criterion sufficient to

Whatever be the content of our conception of an object, it is necessary to go beyond it, if we wish to predicate

existence of the object. In the case of sensuous objects, this is attained by their connection according to

empirical laws with some one of my perceptions; but there is no means of cognizing the existence of objects

of pure thought, because it must be cognized completely a priori. But all our knowledge of existence (be it

immediately by perception, or by inferences connecting some object with a perception) belongs entirely to

the sphere of experience which is in perfect unity with itself; and although an existence out of this sphere

cannot be absolutely declared to be impossible, it is a hypothesis the truth of which we have no means of

The notion of a Supreme Being is in many respects a highly useful idea; but for the very reason that it is an

idea, it is incapable of enlarging our cognition with regard to the existence of things. It is not even sufficient

to instruct us as to the possibility of a being which we do not know to exist. The analytical criterion of

possibility, which consists in the absence of contradiction in propositions, cannot be denied it. But the

connection of real properties in a thing is a synthesis of the possibility of which an a priori judgement cannot

be formed, because these realities are not presented to us specifically; and even if this were to happen, a

judgement would still be impossible, because the criterion of the possibility of synthetical cognitions must be

sought for in the world of experience, to which the object of an idea cannot belong. And thus the celebrated

Leibnitz has utterly failed in his attempt to establish upon a priori grounds the possibility of this sublime ideal

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The celebrated ontological or Cartesian argument for the existence of a Supreme Being is therefore

insufficient; and we may as well hope to increase our stock of knowledge by the aid of mere ideas, as the

It was by no means a natural course of proceeding, but, on the contrary, an invention entirely due to the

subtlety of the schools, to attempt to draw from a mere idea a proof of the existence of an object

corresponding to it. Such a course would never have been pursued, were it not for that need of reason which

requires it to suppose the existence of a necessary being as a basis for the empirical regress, and that, as this

necessity must be unconditioned and a priori, reason is bound to discover a conception which shall satisfy, if

possible, this requirement, and enable us to attain to the a priori cognition of such a being. This conception

was thought to be found in the idea of an ens realissimum, and thus this idea was employed for the attainment

of a better defined knowledge of a necessary being, of the existence of which we were convinced, or

persuaded, on other grounds. Thus reason was seduced from her natural courage; and, instead of concluding

with the conception of an ens realissimum, an attempt was made to begin with it, for the purpose of inferring

from it that idea of a necessary existence which it was in fact called in to complete. Thus arose that

unfortunate ontological argument, which neither satisfies the healthy common sense of humanity, nor

The cosmological proof, which we are about to examine, retains the connection between absolute necessity

and the highest reality; but, instead of reasoning from this highest reality to a necessary existence, like the

preceding argument, it concludes from the given. unconditioned necessity of some being its unlimited reality.

The track it pursues, whether rational or sophistical, is at least natural, and not only goes far to persuade the

common understanding, but shows itself deserving of respect from the speculative intellect; while it contains,

at the same time, the outlines of all the arguments employed in natural theology arguments which always

have been, and still will be, in use and authority. These, however adorned, and hid under whatever

embellishments of rhetoric and sentiment, are at bottom identical with the arguments we are at present to

discuss. This proof, termed by Leibnitz the argumentum a contingentia mundi, I shall now lay before the

It is framed in the following manner: If something exists, an absolutely necessary being must likewise exist.

Now I, at least, exist. Consequently, there exists an absolutely necessary being. The minor contains an

experience, the major reasons from a general experience to the existence of a necessary being.* Thus this

argument really begins at experience, and is not completely a priori, or ontological. The object of all possible

experience being the world, it is called the cosmological proof. It contains no reference to any peculiar

property of sensuous objects, by which this world of sense might be distinguished from other possible

worlds; and in this respect it differs from the physicotheological proof, which is based upon the

*This inference is too well known to require more detailed discussion. It is based upon the spurious

transcendental law of causality, that everything which is contingent has a cause, which, if itself contingent,

must also have a cause; and so on, till the series of subordinated causes must end with an absolutely

The proof proceeds thus: A necessary being can be determined only in one way, that is, it can be determined

by only one of all possible opposed predicates; consequently, it must be completely determined in and by its

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conception. But there is only a single conception of a thing possible, which completely determines the thing a

priori: that is, the conception of the ens realissimum. It follows that the conception of the ens realissimum is

the only conception by and in which we can cogitate a necessary being. Consequently, a Supreme Being

In this cosmological argument are assembled so many sophistical propositions that speculative reason seems

to have exerted in it all her dialectical skill to produce a transcendental illusion of the most extreme character.

We shall postpone an investigation of this argument for the present, and confine ourselves to exposing the

stratagem by which it imposes upon us an old argument in a new dress, and appeals to the agreement of two

witnesses, the one with the credentials of pure reason, and the other with those of empiricism; while, in fact,

it is only the former who has changed his dress and voice, for the purpose of passing himself off for an

additional witness. That it may possess a secure foundation, it bases its conclusions upon experience, and

thus appears to be completely distinct from the ontological argument, which places its confidence entirely in

pure a priori conceptions. But this experience merely aids reason in making one step to the existence of a

necessary being. What the properties of this being are cannot be learned from experience; and therefore

reason abandons it altogether, and pursues its inquiries in the sphere of pure conception, for the purpose of

discovering what the properties of an absolutely necessary being ought to be, that is, what among all possible

things contain the conditions (requisita) of absolute necessity. Reason believes that it has discovered these

requisites in the conception of an ens realissimum and in it alone, and hence concludes: The ens

realissimum is an absolutely necessary being. But it is evident that reason has here presupposed that the

conception of an ens realissimum is perfectly adequate to the conception of a being of absolute necessity, that

is, that we may infer the existence of the latter from that of the former a proposition which formed the basis

of the ontological argument, and which is now employed in the support of the cosmological argument,

contrary to the wish and professions of its inventors. For the existence of an absolutely necessary being is

given in conceptions alone. But if I say: "The conception of the ens realissimum is a conception of this kind,

and in fact the only conception which is adequate to our idea of a necessary being," I am obliged to admit,

that the latter may be inferred from the former. Thus it is properly the ontological argument which figures in

the cosmological, and constitutes the whole strength of the latter; while the spurious basis of experience has

been of no further use than to conduct us to the conception of absolute necessity, being utterly insufficient to

demonstrate the presence of this attribute in any determinate existence or thing. For when we propose to

ourselves an aim of this character, we must abandon the sphere of experience, and rise to that of pure

conceptions, which we examine with the purpose of discovering whether any one contains the conditions of

the possibility of an absolutely necessary being. But if the possibility of such a being is thus demonstrated, its

existence is also proved; for we may then assert that, of all possible beings there is one which possesses the

attribute of necessity in other words, this being possesses an absolutely necessary existence.

All illusions in an argument are more easily detected when they are presented in the formal manner employed

If the proposition: "Every absolutely necessary being is likewise an ens realissimum," is correct (and it is this

which constitutes the nervus probandi of the cosmological argument), it must, like all affirmative judgements,

be capable of conversion the conversio per accidens, at least. It follows, then, that some entia realissima are

absolutely necessary beings. But no ens realissimum is in any respect different from another, and what is

valid of some is valid of all. In this present case, therefore, I may employ simple conversion, and say: "Every

ens realissimum is a necessary being." But as this proposition is determined a priori by the conceptions

contained in it, the mere conception of an ens realissimum must possess the additional attribute of absolute

necessity. But this is exactly what was maintained in the ontological argument, and not recognized by the

cosmological, although it formed the real ground of its disguised and illusory reasoning.

Thus the second mode employed by speculative reason of demonstrating the existence of a Supreme Being, is

not only, like the first, illusory and inadequate, but possesses the additional blemish of an ignoratio elenchi

SECTION V. Of the Impossibility of a Cosmological Proof of the Existence of God. 201

professing to conduct us by a new road to the desired goal, but bringing us back, after a short circuit, to the

I mentioned above that this cosmological argument contains a perfect nest of dialectical assumptions, which

transcendental criticism does not find it difficult to expose and to dissipate. I shall merely enumerate these,

leaving it to the reader, who must by this time be well practised in such matters, to investigate the fallacies

The following fallacies, for example, are discoverable in this mode of proof: 1. The transcendental principle:

"Everything that is contingent must have a cause" a principle without significance, except in the sensuous

world. For the purely intellectual conception of the contingent cannot produce any synthetical proposition,

like that of causality, which is itself without significance or distinguishing characteristic except in the

phenomenal world. But in the present case it is employed to help us beyond the limits of its sphere. 2. "From

the impossibility of an infinite ascending series of causes in the world of sense a first cause is inferred"; a

conclusion which the principles of the employment of reason do not justify even in the sphere of experience,

and still less when an attempt is made to pass the limits of this sphere. 3. Reason allows itself to be satisfied

upon insufficient grounds, with regard to the completion of this series. It removes all conditions (without

which, however, no conception of Necessity can take place); and, as after this it is beyond our power to form

any other conceptions, it accepts this as a completion of the conception it wishes to form of the series. 4. The

logical possibility of a conception of the total of reality (the criterion of this possibility being the absence of

contradiction) is confound. ed with the transcendental, which requires a principle of the practicability of such

a synthesis a principle which again refers us to the world of experience. And so on.

The aim of the cosmological argument is to avoid the necessity of proving the existence of a necessary being

priori from mere conceptions a proof which must be ontological, and of which we feel ourselves quite

incapable. With this purpose, we reason from an actual existence an experience in general, to an absolutely

necessary condition of that existence. It is in this case unnecessary to demonstrate its possibility. For after

having proved that it exists, the question regarding its possibility is superfluous. Now, when we wish to

define more strictly the nature of this necessary being, we do not look out for some being the conception of

which would enable us to comprehend the necessity of its being for if we could do this, an empirical

presupposition would be unnecessary; no, we try to discover merely the negative condition (conditio sine qua

non), without which a being would not be absolutely necessary. Now this would be perfectly admissible in

every sort of reasoning, from a consequence to its principle; but in the present case it unfortunately happens

that the condition of absolute necessity can be discovered in but a single being, the conception of which must

consequently contain all that is requisite for demonstrating the presence of absolute necessity, and thus entitle

me to infer this absolute necessity a priori. That is, it must be possible to reason conversely, and say: The

thing, to which the conception of the highest reality belongs, is absolutely necessary. But if I cannot reason

thus and I cannot, unless I believe in the sufficiency of the ontological argument I find insurmountable

obstacles in my new path, and am really no farther than the point from which I set out. The conception of a

Supreme Being satisfies all questions a priori regarding the internal determinations of a thing, and is for this

reason an ideal without equal or parallel, the general conception of it indicating it as at the same time an ens

individuum among all possible things. But the conception does not satisfy the question regarding its

existence which was the purpose of all our inquiries; and, although the existence of a necessary being were

admitted, we should find it impossible to answer the question: What of all things in the world must be

It is certainly allowable to admit the existence of an allsufficient being a cause of all possible effects for

the purpose of enabling reason to introduce unity into its mode and grounds of explanation with regard to

phenomena. But to assert that such a being necessarily exists, is no longer the modest enunciation of an

admissible hypothesis, but the boldest declaration of an apodeictic certainty; for the cognition of that which is

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The aim of the transcendental ideal formed by the mind is either to discover a conception which shall

harmonize with the idea of absolute necessity, or a conception which shall contain that idea. If the one is

possible, so is the other; for reason recognizes that alone as absolutely necessary which is necessary from its

conception. But both attempts are equally beyond our power we find it impossible to satisfy the

understanding upon this point, and as impossible to induce it to remain at rest in relation to this incapacity.

Unconditioned necessity, which, as the ultimate support and stay of all existing things, is an indispensable

requirement of the mind, is an abyss on the verge of which human reason trembles in dismay. Even the idea

of eternity, terrible and sublime as it is, as depicted by Haller, does not produce upon the mental vision such a

feeling of awe and terror; for, although it measures the duration of things, it does not support them. We

cannot bear, nor can we rid ourselves of the thought that a being, which we regard as the greatest of all

possible existences, should say to himself: I am from eternity to eternity; beside me there is nothing, except

that which exists by my will; whence then am I? Here all sinks away from under us; and the greatest, as the

smallest, perfection, hovers without stay or footing in presence of the speculative reason, which finds it as

Many physical powers, which evidence their existence by their effects, are perfectly inscrutable in their

nature; they elude all our powers of observation. The transcendental object which forms the basis of

phenomena, and, in connection with it, the reason why our sensibility possesses this rather than that particular

kind of conditions, are and must ever remain hidden from our mental vision; the fact is there, the reason of

the fact we cannot see. But an ideal of pure reason cannot be termed mysterious or inscrutable, because the

only credential of its reality is the need of it felt by reason, for the purpose of giving completeness to the

world of synthetical unity. An ideal is not even given as a cogitable object, and therefore cannot be

inscrutable; on the contrary, it must, as a mere idea, be based on the constitution of reason itself, and on this

account must be capable of explanation and solution. For the very essence of reason consists in its ability to

give an account, of all our conceptions, opinions, and assertions upon objective, or, when they happen to be

Both of the above arguments are transcendental; in other words, they do not proceed upon empirical

principles. For, although the cosmological argument professed to lay a basis of experience for its edifice of

reasoning, it did not ground its procedure upon the peculiar constitution of experience, but upon pure

principles of reason in relation to an existence given by empirical consciousness; utterly abandoning its

guidance, however, for the purpose of supporting its assertions entirely upon pure conceptions. Now what is

the cause, in these transcendental arguments, of the dialectical, but natural, illusion, which connects the

conceptions of necessity and supreme reality, and hypostatizes that which cannot be anything but an idea?

What is the cause of this unavoidable step on the part of reason, of admitting that some one among all

existing things must be necessary, while it falls back from the assertion of the existence of such a being as

from an abyss? And how does reason proceed to explain this anomaly to itself, and from the wavering

condition of a timid and reluctant approbation always again withdrawn arrive at a calm and settled insight

It is something very remarkable that, on the supposition that something exists, I cannot avoid the inference

that something exists necessarily. Upon this perfectly natural but not on that account reliable inference

does the cosmological argument rest. But, let me form any conception whatever of a thing, I find that I cannot

cogitate the existence of the thing as absolutely necessary, and that nothing prevents me be the thing or

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being what it may from cogitating its nonexistence. I may thus be obliged to admit that all existing things

have a necessary basis, while I cannot cogitate any single or individual thing as necessary. In other words, I

can never complete the regress through the conditions of existence, without admitting the existence of a

necessary being; but, on the other hand, I cannot make a commencement from this being.

If I must cogitate something as existing necessarily as the basis of existing things, and yet am not permitted to

cogitate any individual thing as in itself necessary, the inevitable inference is that necessity and contingency

are not properties of things themselves otherwise an internal contradiction would result; that consequently

neither of these principles are objective, but merely subjective principles of reason the one requiring us to

seek for a necessary ground for everything that exists, that is, to be satisfied with no other explanation than

that which is complete a priori, the other forbidding us ever to hope for the attainment of this completeness,

that is, to regard no member of the empirical world as unconditioned. In this mode of viewing them, both

principles, in their purely heuristic and regulative character, and as concerning merely the formal interest of

reason, are quite consistent with each other. The one says: "You must philosophize upon nature," as if there

existed a necessary primal basis of all existing things, solely for the purpose of introducing systematic unity

into your knowledge, by pursuing an idea of this character a foundation which is arbitrarily admitted to be

ultimate; while the other warns you to consider no individual determination, concerning the existence of

things, as such an ultimate foundation, that is, as absolutely necessary, but to keep the way always open for

further progress in the deduction, and to treat every determination as determined by some other. But if all that

we perceive must be regarded as conditionally necessary, it is impossible that anything which is empirically

It follows from this that you must accept the absolutely necessary as out of and beyond the world, inasmuch

as it is useful only as a principle of the highest possible unity in experience, and you cannot discover any such

necessary existence in the would, the second rule requiring you to regard all empirical causes of unity as

The philosophers of antiquity regarded all the forms of nature as contingent; while matter was considered by

them, in accordance with the judgement of the common reason of mankind, as primal and necessary. But if

they had regarded matter, not relatively as the substratum of phenomena, but absolutely and in itself as an

independent existence, this idea of absolute necessity would have immediately disappeared. For there is

nothing absolutely connecting reason with such an existence; on the contrary, it can annihilate it in thought,

always and without selfcontradiction. But in thought alone lay the idea of absolute necessity. A regulative

principle must, therefore, have been at the foundation of this opinion. In fact, extension and impenetrability

which together constitute our conception of matter form the supreme empirical principle of the unity of

phenomena, and this principle, in so far as it is empirically unconditioned, possesses the property of a

regulative principle. But, as every determination of matter which constitutes what is real in it and

consequently impenetrability is an effect, which must have a cause, and is for this reason always derived,

the notion of matter cannot harmonize with the idea of a necessary being, in its character of the principle of

all derived unity. For every one of its real properties, being derived, must be only conditionally necessary,

and can therefore be annihilated in thought; and thus the whole existence of matter can be so annihilated or

suppressed. If this were not the case, we should have found in the world of phenomena the highest ground or

condition of unity which is impossible, according to the second regulative principle. It follows that matter,

and, in general, all that forms part of the world of sense, cannot be a necessary primal being, nor even a

principle of empirical unity, but that this being or principle must have its place assigned without the world.

And, in this way, we can proceed in perfect confidence to deduce the phenomena of the world and their

existence from other phenomena, just as if there existed no necessary being; and we can at the same time,

strive without ceasing towards the attainment of completeness for our deduction, just as if such a being the

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These remarks will have made it evident to the reader that the ideal of the Supreme Being, far from being an

enouncement of the existence of a being in itself necessary, is nothing more than a regulative principle of

reason, requiring us to regard all connection existing between phenomena as if it had its origin from an

allsufficient necessary cause, and basing upon this the rule of a systematic and necessary unity in the

explanation of phenomena. We cannot, at the same time, avoid regarding, by a transcendental subreptio, this

formal principle as constitutive, and hypostatizing this unity. Precisely similar is the case with our notion of

space. Space is the primal condition of all forms, which are properly just so many different limitations of it;

and thus, although it is merely a principle of sensibility, we cannot help regarding it as an absolutely

necessary and selfsubsistent thing as an object given a priori in itself. In the same way, it is quite natural

that, as the systematic unity of nature cannot be established as a principle for the empirical employment of

reason, unless it is based upon the idea of an ens realissimum, as the supreme cause, we should regard this

idea as a real object, and this object, in its character of supreme condition, as absolutely necessary, and that in

this way a regulative should be transformed into a constitutive principle. This interchange becomes evident

when I regard this supreme being, which, relatively to the world, was absolutely (unconditionally) necessary,

as a thing per se. In this case, I find it impossible to represent this necessity in or by any conception, and it

exists merely in my own mind, as the formal condition of thought, but not as a material and hypostatic

If, then, neither a pure conception nor the general experience of an existing being can provide a sufficient

basis for the proof of the existence of the Deity, we can make the attempt by the only other mode that of

grounding our argument upon a determinate experience of the phenomena of the present world, their

constitution and disposition, and discover whether we can thus attain to a sound conviction of the existence of

a Supreme Being. This argument we shall term the physicotheological argument. If it is shown to be

insufficient, speculative reason cannot present us with any satisfactory proof of the existence of a being

It is evident from the remarks that have been made in the preceding sections, that an answer to this question

will be far from being difficult or unconvincing. For how can any experience be adequate with an idea? The

very essence of an idea consists in the fact that no experience can ever be discovered congruent or adequate

with it. The transcendental idea of a necessary and allsufficient being is so immeasurably great, so high

above all that is empirical, which is always conditioned, that we hope in vain to find materials in the sphere

of experience sufficiently ample for our conception, and in vain seek the unconditioned among things that are

conditioned, while examples, nay, even guidance is denied us by the laws of empirical synthesis.

If the Supreme Being forms a link in the chain of empirical conditions, it must be a member of the empirical

series, and, like the lower members which it precedes, have its origin in some higher member of the series. If,

on the other hand, we disengage it from the chain, and cogitate it as an intelligible being, apart from the series

of natural causes how shall reason bridge the abyss that separates the latter from the former? All laws

respecting the regress from effects to causes, all synthetical additions to our knowledge relate solely to

possible experience and the objects of the sensuous world, and, apart from them, are without significance.

The world around us opens before our view so magnificent a spectacle of order, variety, beauty, and

conformity to ends, that whether we pursue our observations into the infinity of space in the one direction, or

into its illimitable divisions in the other, whether we regard the world in its greatest or its least

manifestations even after we have attained to the highest summit of knowledge which our weak minds can

reach, we find that language in the presence of wonders so inconceivable has lost its force, and number its

power to reckon, nay, even thought fails to conceive adequately, and our conception of the whole dissolves

into an astonishment without power of expression all the more eloquent that it is dumb. Everywhere around

us we observe a chain of causes and effects, of means and ends, of death and birth; and, as nothing has

entered of itself into the condition in which we find it, we are constantly referred to some other thing, which

itself suggests the same inquiry regarding its cause, and thus the universe must sink into the abyss of

nothingness, unless we admit that, besides this infinite chain of contingencies, there exists something that is

primal and selfsubsistent something which, as the cause of this phenomenal world, secures its continuance

This highest cause what magnitude shall we attribute to it? Of the content of the world we are ignorant; still

less can we estimate its magnitude by comparison with the sphere of the possible. But this supreme cause

being a necessity of the human mind, what is there to prevent us from attributing to it such a degree of

perfection as to place it above the sphere of all that is possible? This we can easily do, although only by the

aid of the faint outline of an abstract conception, by representing this being to ourselves as containing in

itself, as an individual substance, all possible perfection a conception which satisfies that requirement of

reason which demands parsimony in principles, which is free from selfcontradiction, which even contributes

to the extension of the employment of reason in experience, by means of the guidance afforded by this idea to

This argument always deserves to be mentioned with respect. It is the oldest, the clearest, and that most in

conformity with the common reason of humanity. It animates the study of nature, as it itself derives its

existence and draws ever new strength from that source. It introduces aims and ends into a sphere in which

our observation could not of itself have discovered them, and extends our knowledge of nature, by directing

our attention to a unity, the principle of which lies beyond nature. This knowledge of nature again reacts upon

this idea its cause; and thus our belief in a divine author of the universe rises to the power of an irresistible

For these reasons it would be utterly hopeless to attempt to rob this argument of the authority it has always

enjoyed. The mind, unceasingly elevated by these considerations, which, although empirical, are so

remarkably powerful, and continually adding to their force, will not suffer itself to be depressed by the doubts

suggested by subtle speculation; it tears itself out of this state of uncertainty, the moment it casts a look upon

the wondrous forms of nature and the majesty of the universe, and rises from height to height, from condition

to condition, till it has elevated itself to the supreme and unconditioned author of all.

But although we have nothing to object to the reasonableness and utility of this procedure, but have rather to

commend and encourage it, we cannot approve of the claims which this argument advances to demonstrative

certainty and to a reception upon its own merits, apart from favour or support by other arguments. Nor can it

injure the cause of morality to endeavour to lower the tone of the arrogant sophist, and to teach him that

modesty and moderation which are the properties of a belief that brings calm and content into the mind,

without prescribing to it an unworthy subjection. I maintain, then, that the physicotheological argument is

insufficient of itself to prove the existence of a Supreme Being, that it must entrust this to the ontological

argument to which it serves merely as an introduction, and that, consequently, this argument contains the

only possible ground of proof (possessed by speculative reason) for the existence of this being.

The chief momenta in the physicotheological argument are as follow: 1. We observe in the world manifest

signs of an arrangement full of purpose, executed with great wisdom, and argument in whole of a content

indescribably various, and of an extent without limits. 2. This arrangement of means and ends is entirely

foreign to the things existing in the world it belongs to them merely as a contingent attribute; in other words,

the nature of different things could not of itself, whatever means were employed, harmoniously tend towards

certain purposes, were they not chosen and directed for these purposes by a rational and disposing principle,

in accordance with certain fundamental ideas. 3. There exists, therefore, a sublime and wise cause (or

several), which is not merely a blind, allpowerful nature, producing the beings and events which fill the

world in unconscious fecundity, but a free and intelligent cause of the world. 4. The unity of this cause may

be inferred from the unity of the reciprocal relation existing between the parts of the world, as portions of an

artistic edifice an inference which all our observation favours, and all principles of analogy support.

In the above argument, it is inferred from the analogy of certain products of nature with those of human art,

when it compels Nature to bend herself to its purposes, as in the case of a house, a ship, or a watch, that the

same kind of causality namely, understanding and will resides in nature. It is also declared that the internal

possibility of this freelyacting nature (which is the source of all art, and perhaps also of human reason) is

derivable from another and superhuman art a conclusion which would perhaps be found incapable of

standing the test of subtle transcendental criticism. But to neither of these opinions shall we at present object.

We shall only remark that it must be confessed that, if we are to discuss the subject of cause at all, we cannot

proceed more securely than with the guidance of the analogy subsisting between nature and such products of

design these being the only products whose causes and modes of organization are completely known to us.

Reason would be unable to satisfy her own requirements, if she passed from a causality which she does

know, to obscure and indemonstrable principles of explanation which she does not know.

According to the physicotheological argument, the connection and harmony existing in the world evidence

the contingency of the form merely, but not of the matter, that is, of the substance of the world. To establish

the truth of the latter opinion, it would be necessary to prove that all things would be in themselves incapable

of this harmony and order, unless they were, even as regards their substance, the product of a supreme

wisdom. But this would require very different grounds of proof from those presented by the analogy with

human art. This proof can at most, therefore, demonstrate the existence of an architect of the world, whose

efforts are limited by the capabilities of the material with which he works, but not of a creator of the world, to

whom all things are subject. Thus this argument is utterly insufficient for the task before us a demonstration

of the existence of an allsufficient being. If we wish to prove the contingency of matter, we must have

recourse to a transcendental argument, which the physicotheological was constructed expressly to avoid.

We infer, from the order and design visible in the universe, as a disposition of a thoroughly contingent

character, the existence of a cause proportionate thereto. The conception of this cause must contain certain

determinate qualities, and it must therefore be regarded as the conception of a being which possesses all

power, wisdom, and so on, in one word, all perfection the conception, that is, of an allsufficient being. For

the predicates of very great, astonishing, or immeasurable power and excellence, give us no determinate

conception of the thing, nor do they inform us what the thing may be in itself. They merely indicate the

relation existing between the magnitude of the object and the observer, who compares it with himself and

with his own power of comprehension, and are mere expressions of praise and reverence, by which the object

is either magnified, or the observing subject depreciated in relation to the object. Where we have to do with

the magnitude (of the perfection) of a thing, we can discover no determinate conception, except that which

comprehends all possible perfection or completeness, and it is only the total (omnitudo) of reality which is

Now it cannot be expected that any one will be bold enough to declare that he has a perfect insight into the

relation which the magnitude of the world he contemplates bears (in its extent as well as in its content) to

omnipotence, into that of the order and design in the world to the highest wisdom, and that of the unity of the

world to the absolute unity of a Supreme Being. Physicotheology is therefore incapable of presenting a

determinate conception of a supreme cause of the world, and is therefore insufficient as a principle of

The attainment of absolute totality is completely impossible on the path of empiricism. And yet this is the

path pursued in the physicotheological argument. What means shall we employ to bridge the abyss?

After elevating ourselves to admiration of the magnitude of the power, wisdom, and other attributes of the

author of the world, and finding we can advance no further, we leave the argument on empirical grounds, and

proceed to infer the contingency of the world from the order and conformity to aims that are observable in it.

From this contingency we infer, by the help of transcendental conceptions alone, the existence of something

absolutely necessary; and, still advancing, proceed from the conception of the absolute necessity of the first

cause to the completely determined or determining conception thereof the conception of an allembracing

reality. Thus the physicotheological, failing in its undertaking, recurs in its embarrassment to the

cosmological argument; and, as this is merely the ontological argument in disguise, it executes its design

solely by the aid of pure reason, although it at first professed to have no connection with this faculty and to

The physicotheologians have therefore no reason to regard with such contempt the transcendental mode of

argument, and to look down upon it, with the conceit of clearsighted observers of nature, as the

braincobweb of obscure speculatists. For, if they reflect upon and examine their own arguments, they will

find that, after following for some time the path of nature and experience, and discovering themselves no

nearer their object, they suddenly leave this path and pass into the region of pure possibility, where they hope

to reach upon the wings of ideas what had eluded all their empirical investigations. Gaining, as they think, a

firm footing after this immense leap, they extend their determinate conception into the possession of which

they have come, they know not how over the whole sphere of creation, and explain their ideal, which is

entirely a product of pure reason, by illustrations drawn from experience though in a degree miserably

unworthy of the grandeur of the object, while they refuse to acknowledge that they have arrived at this

Thus the physicotheological is based upon the cosmological, and this upon the ontological proof of the

existence of a Supreme Being; and as besides these three there is no other path open to speculative reason, the

ontological proof, on the ground of pure conceptions of reason, is the only possible one, if any proof of a

proposition so far transcending the empirical exercise of the understanding is possible at all.

If by the term theology I understand the cognition of a primal being, that cognition is based either upon

reason alone (theologia rationalis) or upon revelation (theologia revelata). The former cogitates its object

either by means of pure transcendental conceptions, as an ens originarium, realissimum, ens entium, and is

termed transcendental theology; or, by means of a conception derived from the nature of our own mind, as a

supreme intelligence, and must then be entitled natural theology. The person who believes in a transcendental

theology alone, is termed a deist; he who acknowledges the possibility of a natural theology also, a theist.

The former admits that we can cognize by pure reason alone the existence of a Supreme Being, but at the

same time maintains that our conception of this being is purely transcendental, and that all we can say of it is

that it possesses all reality, without being able to define it more closely. The second asserts that reason is

capable of presenting us, from the analogy with nature, with a more definite conception of this being, and that

its operations, as the cause of all things, are the results of intelligence and free will. The former regards the

Supreme Being as the cause of the world whether by the necessity of his nature, or as a free agent, is left

Transcendental theology aims either at inferring the existence of a Supreme Being from a general experience,

without any closer reference to the world to which this experience belongs, and in this case it is called

cosmotheology; or it endeavours to cognize the existence of such a being, through mere conceptions, without

Natural theology infers the attributes and the existence of an author of the world, from the constitution of, the

order and unity observable in, the world, in which two modes of causality must be admitted to exist those of

nature and freedom. Thus it rises from this world to a supreme intelligence, either as the principle of all

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natural, or of all moral order and perfection. In the former case it is termed physicotheology, in the latter,

*Not theological ethics; for this science contains ethical laws, which presuppose the existence of a Supreme

Governor of the world; while moraltheology, on the contrary, is the expression of a conviction of the

As we are wont to understand by the term God not merely an eternal nature, the operations of which are

insensate and blind, but a Supreme Being, who is the free and intelligent author of all things, and as it is this

latter view alone that can be of interest to humanity, we might, in strict rigour, deny to the deist any belief in

God at all, and regard him merely as a maintainer of the existence of a primal being or thing the supreme

cause of all other things. But, as no one ought to be blamed, merely because he does not feel himself justified

in maintaining a certain opinion, as if he altogether denied its truth and asserted the opposite, it is more

correct as it is less harsh to say, the deist believes in a God, the theist in a living God (summa

intelligentia). We shall now proceed to investigate the sources of all these attempts of reason to establish the

It may be sufficient in this place to define theoretical knowledge or cognition as knowledge of that which is,

and practical knowledge as knowledge of that which ought to be. In this view, the theoretical employment of

reason is that by which I cognize a priori (as necessary) that something is, while the practical is that by which

I cognize a priori what ought to happen. Now, if it is an indubitably certain, though at the same time an

entirely conditioned truth, that something is, or ought to happen, either a certain determinate condition of this

truth is absolutely necessary, or such a condition may be arbitrarily presupposed. In the former case the

condition is postulated (per thesin), in the latter supposed (per hypothesin). There are certain practical laws

those of morality which are absolutely necessary. Now, if these laws necessarily presuppose the existence of

some being, as the condition of the possibility of their obligatory power, this being must be postulated,

because the conditioned, from which we reason to this determinate condition, is itself cognized a priori as

absolutely necessary. We shall at some future time show that the moral laws not merely presuppose the

existence of a Supreme Being, but also, as themselves absolutely necessary in a different relation, demand or

postulate it although only from a practical point of view. The discussion of this argument we postpone for

When the question relates merely to that which is, not to that which ought to be, the conditioned which is

presented in experience is always cogitated as contingent. For this reason its condition cannot be regarded as

absolutely necessary, but merely as relatively necessary, or rather as needful; the condition is in itself and a

priori a mere arbitrary presupposition in aid of the cognition, by reason, of the conditioned. If, then, we are to

possess a theoretical cognition of the absolute necessity of a thing, we cannot attain to this cognition

otherwise than a priori by means of conceptions; while it is impossible in this way to cognize the existence of

Theoretical cognition is speculative when it relates to an object or certain conceptions of an object which is

not given and cannot be discovered by means of experience. It is opposed to the cognition of nature, which

concerns only those objects or predicates which can be presented in a possible experience.

The principle that everything which happens (the empirically contingent) must have a cause, is a principle of

the cognition of nature, but not of speculative cognition. For, if we change it into an abstract principle, and

deprive it of its reference to experience and the empirical, we shall find that it cannot with justice be regarded

any longer as a synthetical proposition, and that it is impossible to discover any mode of transition from that

which exists to something entirely different termed cause. Nay, more, the conception of a cause likewise

that of the contingent loses, in this speculative mode of employing it, all significance, for its objective

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When from the existence of the universe and the things in it the existence of a cause of the universe is

inferred, reason is proceeding not in the natural, but in the speculative method. For the principle of the former

enounces, not that things themselves or substances, but only that which happens or their states as

empirically contingent, have a cause: the assertion that the existence of substance itself is contingent is not

justified by experience, it is the assertion of a reason employing its principles in a speculative manner. If,

again, I infer from the form of the universe, from the way in which all things are connected and act and react

upon each other, the existence of a cause entirely distinct from the universe this would again be a judgement

of purely speculative reason; because the object in this case the cause can never be an object of possible

experience. In both these cases the principle of causality, which is valid only in the field of experience

useless and even meaningless beyond this region, would be diverted from its proper destination.

Now I maintain that all attempts of reason to establish a theology by the aid of speculation alone are fruitless,

that the principles of reason as applied to nature do not conduct us to any theological truths, and,

consequently, that a rational theology can have no existence, unless it is founded upon the laws of morality.

For all synthetical principles of the understanding are valid only as immanent in experience; while the

cognition of a Supreme Being necessitates their being employed transcendentally, and of this the

understanding is quite incapable. If the empirical law of causality is to conduct us to a Supreme Being, this

being must belong to the chain of empirical objects in which case it would be, like all phenomena, itself

conditioned. If the possibility of passing the limits of experience be admitted, by means of the dynamical law

of the relation of an effect to its cause, what kind of conception shall we obtain by this procedure? Certainly

not the conception of a Supreme Being, because experience never presents us with the greatest of all possible

effects, and it is only an effect of this character that could witness to the existence of a corresponding cause.

If, for the purpose of fully satisfying the requirements of Reason, we recognize her right to assert the

existence of a perfect and absolutely necessary being, this can be admitted only from favour, and cannot be

regarded as the result or irresistible demonstration. The physicotheological proof may add weight to others

if other proofs there are by connecting speculation with experience; but in itself it rather prepares the mind

for theological cognition, and gives it a right and natural direction, than establishes a sure foundation for

It is now perfectly evident that transcendental questions admit only of transcendental answers those

presented a priori by pure conceptions without the least empirical admixture. But the question in the present

case is evidently synthetical it aims at the extension of our cognition beyond the bounds of experience it

requires an assurance respecting the existence of a being corresponding with the idea in our minds, to which

no experience can ever be adequate. Now it has been abundantly proved that all a priori synthetical cognition

is possible only as the expression of the formal conditions of a possible experience; and that the validity of all

principles depends upon their immanence in the field of experience, that is, their relation to objects of

empirical cognition or phenomena. Thus all transcendental procedure in reference to speculative theology is

If any one prefers doubting the conclusiveness of the proofs of our analytic to losing the persuasion of the

validity of these old and time honoured arguments, he at least cannot decline answering the question how he

can pass the limits of all possible experience by the help of mere ideas. If he talks of new arguments, or of

improvements upon old arguments, I request him to spare me. There is certainly no great choice in this sphere

of discussion, as all speculative arguments must at last look for support to the ontological, and I have,

therefore, very little to fear from the argumentative fecundity of the dogmatical defenders of a nonsensuous

reason. Without looking upon myself as a remarkably combative person, I shall not decline the challenge to

detect the fallacy and destroy the pretensions of every attempt of speculative theology. And yet the hope of

better fortune never deserts those who are accustomed to the dogmatical mode of procedure. I shall, therefore,

restrict myself to the simple and equitable demand that such reasoners will demonstrate, from the nature of

the human mind as well as from that of the other sources of knowledge, how we are to proceed to extend our

cognition completely a priori, and to carry it to that point where experience abandons us, and no means exist

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 210

of guaranteeing the objective reality of our conceptions. In whatever way the understanding may have

attained to a conception, the existence of the object of the conception cannot be discovered in it by analysis,

because the cognition of the existence of the object depends upon the object's being posited and given in itself

apart from the conception. But it is utterly impossible to go beyond our conception, without the aid of

experience which presents to the mind nothing but phenomena, or to attain by the help of mere conceptions

to a conviction of the existence of new kinds of objects or supernatural beings.

But although pure speculative reason is far from sufficient to demonstrate the existence of a Supreme Being,

it is of the highest utility in correcting our conception of this being on the supposition that we can attain to

the cognition of it by some other means in making it consistent with itself and with all other conceptions of

intelligible objects, clearing it from all that is incompatible with the conception of an ens summun, and

Transcendental theology is still therefore, notwithstanding its objective insufficiency, of importance in a

negative respect; it is useful as a test of the procedure of reason when engaged with pure ideas, no other than

a transcendental standard being in this case admissible. For if, from a practical point of view, the hypothesis

of a Supreme and Allsufficient Being is to maintain its validity without opposition, it must be of the highest

importance to define this conception in a correct and rigorous manner as the transcendental conception of a

necessary being, to eliminate all phenomenal elements (anthropomorphism in its most extended

signification), and at the same time to overflow all contradictory assertions be they atheistic, deistic, or

anthropomorphic. This is of course very easy; as the same arguments which demonstrated the inability of

human reason to affirm the existence of a Supreme Being must be alike sufficient to prove the invalidity of its

denial. For it is impossible to gain from the pure speculation of reason demonstration that there exists no

Supreme Being, as the ground of all that exists, or that this being possesses none of those properties which

we regard as analogical with the dynamical qualities of a thinking being, or that, as the anthropomorphists

would have us believe, it is subject to all the limitations which sensibility imposes upon those intelligences

A Supreme Being is, therefore, for the speculative reason, a mere ideal, though a faultless one a conception

which perfects and crowns the system of human cognition, but the objective reality of which can neither be

proved nor disproved by pure reason. If this defect is ever supplied by a moral theology, the problematic

transcendental theology which has preceded, will have been at least serviceable as demonstrating the mental

necessity existing for the conception, by the complete determination of it which it has furnished, and the

ceaseless testing of the conclusions of a reason often deceived by sense, and not always in harmony with its

own ideas. The attributes of necessity, infinitude, unity, existence apart from the world (and not as a world

soul), eternity (free from conditions of time), omnipresence (free from conditions of space), omnipotence,

and others, are pure transcendental predicates; and thus the accurate conception of a Supreme Being, which

every theology requires, is furnished by transcendental theology alone. APPENDIX

The result of all the dialectical attempts of pure reason not only confirms the truth of what we have already

proved in our Transcendental Analytic, namely, that all inferences which would lead us beyond the limits of

experience are fallacious and groundless, but it at the same time teaches us this important lesson, that human

reason has a natural inclination to overstep these limits, and that transcendental ideas are as much the natural

property of the reason as categories are of the understanding. There exists this difference, however, that while

the categories never mislead us, outward objects being always in perfect harmony therewith, ideas are the

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parents of irresistible illusions, the severest and most subtle criticism being required to save us from the

Whatever is grounded in the nature of our powers will be found to be in harmony with the final purpose and

proper employment of these powers, when once we have discovered their true direction and aim. We are

entitled to suppose, therefore, that there exists a mode of employing transcendental ideas which is proper and

immanent; although, when we mistake their meaning, and regard them as conceptions of actual things, their

mode of application is transcendent and delusive. For it is not the idea itself, but only the employment of the

idea in relation to possible experience, that is transcendent or immanent. An idea is employed transcendently,

when it is applied to an object falsely believed to be adequate with and to correspond to it; imminently, when

it is applied solely to the employment of the understanding in the sphere of experience. Thus all errors of

subreptio of misapplication, are to be ascribed to defects of judgement, and not to understanding or reason.

Reason never has an immediate relation to an object; it relates immediately to the understanding alone. It is

only through the understanding that it can be employed in the field of experience. It does not form

conceptions of objects, it merely arranges them and gives to them that unity which they are capable of

possessing when the sphere of their application has been extended as widely as possible. Reason avails itself

of the conception of the understanding for the sole purpose of producing totality in the different series. This

totality the understanding does not concern itself with; its only occupation is the connection of experiences,

by which series of conditions in accordance with conceptions are established. The object of reason is,

therefore, the understanding and its proper destination. As the latter brings unity into the diversity of objects

by means of its conceptions, so the former brings unity into the diversity of conceptions by means of ideas; as

it sets the final aim of a collective unity to the operations of the understanding, which without this occupies

I accordingly maintain that transcendental ideas can never be employed as constitutive ideas, that they cannot

be conceptions of objects, and that, when thus considered, they assume a fallacious and dialectical character.

But, on the other hand, they are capable of an admirable and indispensably necessary application to objects

as regulative ideas, directing the understanding to a certain aim, the guiding lines towards which all its laws

follow, and in which they all meet in one point. This point though a mere idea (focus imaginarius), that is,

not a point from which the conceptions of the understanding do really proceed, for it lies beyond the sphere

of possible experience serves, notwithstanding, to give to these conceptions the greatest possible unity

combined with the greatest possible extension. Hence arises the natural illusion which induces us to believe

that these lines proceed from an object which lies out of the sphere of empirical cognition, just as objects

reflected in a mirror appear to be behind it. But this illusion which we may hinder from imposing upon us

is necessary and unavoidable, if we desire to see, not only those objects which lie before us, but those which

are at a great distance behind us; that is to say, when, in the present case, we direct the aims of the

understanding, beyond every given experience, towards an extension as great as can possibly be attained.

If we review our cognitions in their entire extent, we shall find that the peculiar business of reason is to

arrange them into a system, that is to say, to give them connection according to a principle. This unity

presupposes an idea the idea of the form of a whole (of cognition), preceding the determinate cognition of

the parts, and containing the conditions which determine a priori to every part its place and relation to the

other parts of the whole system. This idea, accordingly, demands complete unity in the cognition of the

understanding not the unity of a contingent aggregate, but that of a system connected according to necessary

laws. It cannot be affirmed with propriety that this idea is a conception of an object; it is merely a conception

of the complete unity of the conceptions of objects, in so far as this unity is available to the understanding as

a rule. Such conceptions of reason are not derived from nature; on the contrary, we employ them for the

interrogation and investigation of nature, and regard our cognition as defective so long as it is not adequate to

them. We admit that such a thing as pure earth, pure water, or pure air, is not to be discovered. And yet we

require these conceptions (which have their origin in the reason, so far as regards their absolute purity and

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 212

completeness) for the purpose of determining the share which each of these natural causes has in every

phenomenon. Thus the different kinds of matter are all ref erred to earths, as mere weight; to salts and

inflammable bodies, as pure force; and finally, to water and air, as the vehicula of the former, or the machines

employed by them in their operations for the purpose of explaining the chemical action and reaction of

bodies in accordance with the idea of a mechanism. For, although not actually so expressed, the influence of

such ideas of reason is very observable in the procedure of natural philosophers.

If reason is the faculty of deducing the particular from the general, and if the general be certain in se and

given, it is only necessary that the judgement should subsume the particular under the general, the particular

being thus necessarily determined. I shall term this the demonstrative or apodeictic employment of reason. If,

however, the general is admitted as problematical only, and is a mere idea, the particular case is certain, but

the universality of the rule which applies to this particular case remains a problem. Several particular cases,

the certainty of which is beyond doubt, are then taken and examined, for the purpose of discovering whether

the rule is applicable to them; and if it appears that all the particular cases which can be collected follow from

the rule, its universality is inferred, and at the same time, all the causes which have not, or cannot be

presented to our observation, are concluded to be of the same character with those which we have observed.

The hypothetical exercise of reason by the aid of ideas employed as problematical conceptions is properly not

constitutive. That is to say, if we consider the subject strictly, the truth of the rule, which has been employed

as an hypothesis, does not follow from the use that is made of it by reason. For how can we know all the

possible cases that may arise? some of which may, however, prove exceptions to the universality of the rule.

This employment of reason is merely regulative, and its sole aim is the introduction of unity into the

aggregate of our particular cognitions, and thereby the approximating of the rule to universality.

The object of the hypothetical employment of reason is therefore the systematic unity of cognitions; and this

unity is the criterion of the truth of a rule. On the other hand, this systematic unity as a mere idea is in fact

merely a unity projected, not to be regarded as given, but only in the light of a problem a problem which

serves, however, as a principle for the various and particular exercise of the understanding in experience,

directs it with regard to those cases which are not presented to our observation, and introduces harmony and

All that we can be certain of from the above considerations is that this systematic unity is a logical principle,

whose aim is to assist the understanding, where it cannot of itself attain to rules, by means of ideas, to bring

all these various rules under one principle, and thus to ensure the most complete consistency and connection

that can be attained. But the assertion that objects and the understanding by which they are cognized are so

constituted as to be determined to systematic unity, that this may be postulated a priori, without any reference

to the interest of reason, and that we are justified in declaring all possible cognitions empirical and others

to possess systematic unity, and to be subject to general principles from which, notwithstanding their various

character, they are all derivable such an assertion can be founded only upon a transcendental principle of

reason, which would render this systematic unity not subjectively and logically in its character of a method,

We shall illustrate this by an example. The conceptions of the understanding make us acquainted, among

many other kinds of unity, with that of the causality of a substance, which is termed power. The different

phenomenal manifestations of the same substance appear at first view to be so very dissimilar that we are

inclined to assume the existence of just as many different powers as there are different effects as, in the case

of the human mind, we have feeling, consciousness, imagination, memory, wit, analysis, pleasure, desire and

so on. Now we are required by a logical maxim to reduce these differences to as small a number as possible,

by comparing them and discovering the hidden identity which exists. We must inquire, for example, whether

or not imagination (connected with consciousness), memory, wit, and analysis are not merely different forms

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of understanding and reason. The idea of a fundamental power, the existence of which no effort of logic can

assure us of, is the problem to be solved, for the systematic representation of the existing variety of powers.

The logical principle of reason requires us to produce as great a unity as is possible in the system of our

cognitions; and the more the phenomena of this and the other power are found to be identical, the more

probable does it become, that they are nothing but different manifestations of one and the same power, which

may be called, relatively speaking, a fundamental power. And so with other cases.

These relatively fundamental powers must again be compared with each other, to discover, if possible, the

one radical and absolutely fundamental power of which they are but the manifestations. But this unity is

purely hypothetical. It is not maintained, that this unity does really exist, but that we must, in the interest of

reason, that is, for the establishment of principles for the various rules presented by experience, try to

discover and introduce it, so far as is practicable, into the sphere of our cognitions.

But the transcendental employment of the understanding would lead us to believe that this idea of a

fundamental power is not problematical, but that it possesses objective reality, and thus the systematic unity

of the various powers or forces in a substance is demanded by the understanding and erected into an

apodeictic or necessary principle. For, without having attempted to discover the unity of the various powers

existing in nature, nay, even after all our attempts have failed, we notwithstanding presuppose that it does

exist, and may be, sooner or later, discovered. And this reason does, not only, as in the case above adduced,

with regard to the unity of substance, but where many substances, although all to a certain extent

homogeneous, are discoverable, as in the case of matter in general. Here also does reason presuppose the

existence of the systematic unity of various powers inasmuch as particular laws of nature are subordinate to

general laws; and parsimony in principles is not merely an economical principle of reason, but an essential

We cannot understand, in fact, how a logical principle of unity can of right exist, unless we presuppose a

transcendental principle, by which such a systematic unit as a property of objects themselves is regarded as

necessary a priori. For with what right can reason, in its logical exercise, require us to regard the variety of

forces which nature displays, as in effect a disguised unity, and to deduce them from one fundamental force

or power, when she is free to admit that it is just as possible that all forces should be different in kind, and

that a systematic unity is not conformable to the design of nature? In this view of the case, reason would be

proceeding in direct opposition to her own destination, by setting as an aim an idea which entirely conflicts

with the procedure and arrangement of nature. Neither can we assert that reason has previously inferred this

unity from the contingent nature of phenomena. For the law of reason which requires us to seek for this unity

is a necessary law, inasmuch as without it we should not possess a faculty of reason, nor without reason a

consistent and selfaccordant mode of employing the understanding, nor, in the absence of this, any proper

and sufficient criterion of empirical truth. In relation to this criterion, therefore, we must suppose the idea of

We find this transcendental presupposition lurking in different forms in the principles of philosophers,

although they have neither recognized it nor confessed to themselves its presence. That the diversities of

individual things do not exclude identity of species, that the various species must be considered as merely

different determinations of a few genera, and these again as divisions of still higher races, and so on that,

accordingly, a certain systematic unity of all possible empirical conceptions, in so far as they can be deduced

from higher and more general conceptions, must be sought for, is a scholastic maxim or logical principle,

without which reason could not be employed by us. For we can infer the particular from the general, only in

so far as general properties of things constitute the foundation upon which the particular rest.

That the same unity exists in nature is presupposed by philosophers in the wellknown scholastic maxim,

which forbids us unnecessarily to augment the number of entities or principles (entia praeter necessitatem non

esse multiplicanda). This maxim asserts that nature herself assists in the establishment of this unity of reason,

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and that the seemingly infinite diversity of phenomena should not deter us from the expectation of

discovering beneath this diversity a unity of fundamental properties, of which the aforesaid variety is but a

more or less determined form. This unity, although a mere idea, thinkers have found it necessary rather to

moderate the desire than to encourage it. It was considered a great step when chemists were able to reduce all

salts to two main genera acids and alkalis; and they regard this difference as itself a mere variety, or

different manifestation of one and the same fundamental material. The different kinds of earths (stones and

even metals) chemists have endeavoured to reduce to three, and afterwards to two; but still, not content with

this advance, they cannot but think that behind these diversities there lurks but one genus nay, that even

salts and earths have a common principle. It might be conjectured that this is merely an economical plan of

reason, for the purpose of sparing itself trouble, and an attempt of a purely hypothetical character, which,

when successful, gives an appearance of probability to the principle of explanation employed by the reason.

But a selfish purpose of this kind is easily to be distinguished from the idea, according to which every one

presupposes that this unity is in accordance with the laws of nature, and that reason does not in this case

request, but requires, although we are quite unable to determine the proper limits of this unity.

If the diversity existing in phenomena a diversity not of form (for in this they may be similar) but of

content were so great that the subtlest human reason could never by comparison discover in them the least

similarity (which is not impossible), in this case the logical law of genera would be without foundation, the

conception of a genus, nay, all general conceptions would be impossible, and the faculty of the

understanding, the exercise of which is restricted to the world of conceptions, could not exist. The logical

principle of genera, accordingly, if it is to be applied to nature (by which I mean objects presented to our

senses), presupposes a transcendental principle. In accordance with this principle, homogeneity is necessarily

presupposed in the variety of phenomena (although we are unable to determine a priori the degree of this

homogeneity), because without it no empirical conceptions, and consequently no experience, would be

The logical principle of genera, which demands identity in phenomena, is balanced by another principle that

of species, which requires variety and diversity in things, notwithstanding their accordance in the same genus,

and directs the understanding to attend to the one no less than to the other. This principle (of the faculty of

distinction) acts as a check upon the reason and reason exhibits in this respect a double and conflicting

interest on the one hand, the interest in the extent (the interest of generality) in relation to genera; on the

other, that of the content (the interest of individuality) in relation to the variety of species. In the former case,

the understanding cogitates more under its conceptions, in the latter it cogitates more in them. This distinction

manifests itself likewise in the habits of thought peculiar to natural philosophers, some of whom the

remarkably speculative heads may be said to be hostile to heterogeneity in phenomena, and have their eyes

always fixed on the unity of genera, while others with a strong empirical tendency aim unceasingly at the

analysis of phenomena, and almost destroy in us the hope of ever being able to estimate the character of these

The latter mode of thought is evidently based upon a logical principle, the aim of which is the systematic

completeness of all cognitions. This principle authorizes me, beginning at the genus, to descend to the

various and diverse contained under it; and in this way extension, as in the former case unity, is assured to the

system. For if we merely examine the sphere of the conception which indicates a genus, we cannot discover

how far it is possible to proceed in the division of that sphere; just as it is impossible, from the consideration

of the space occupied by matter, to determine how far we can proceed in the division of it. Hence every genus

must contain different species, and these again different subspecies; and as each of the latter must itself

contain a sphere (must be of a certain extent, as a conceptus communis), reason demands that no species or

subspecies is to be considered as the lowest possible. For a species or subspecies, being always a

conception, which contains only what is common to a number of different things, does not completely

determine any individual thing, or relate immediately to it, and must consequently contain other conceptions,

that is, other subspecies under it. This law of specification may be thus expressed: entium varietates non

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But it is easy to see that this logical law would likewise be without sense or application, were it not based

upon a transcendental law of specification, which certainly does not require that the differences existing

phenomena should be infinite in number, for the logical principle, which merely maintains the

indeterminateness of the logical sphere of a conception, in relation to its possible division, does not authorize

this statement; while it does impose upon the understanding the duty of searching for subspecies to every

species, and minor differences in every difference. For, were there no lower conceptions, neither could there

be any higher. Now the understanding cognizes only by means of conceptions; consequently, how far soever

it may proceed in division, never by mere intuition, but always by lower and lower conceptions. The

cognition of phenomena in their complete determination (which is possible only by means of the

understanding) requires an unceasingly continued specification of conceptions, and a progression to ever

smaller differences, of which abstraction bad been made in the conception of the species, and still more in

This law of specification cannot be deduced from experience; it can never present us with a principle of so

universal an application. Empirical specification very soon stops in its distinction of diversities, and requires

the guidance of the transcendental law, as a principle of the reason a law which imposes on us the necessity

of never ceasing in our search for differences, even although these may not present themselves to the senses.

That absorbent earths are of different kinds could only be discovered by obeying the anticipatory law of

reason, which imposes upon the understanding the task of discovering the differences existing between these

earths, and supposes that nature is richer in substances than our senses would indicate. The faculty of the

understanding belongs to us just as much under the presupposition of differences in the objects of nature, as

under the condition that these objects are homogeneous, because we could not possess conceptions, nor make

any use of our understanding, were not the phenomena included under these conceptions in some respects

Reason thus prepares the sphere of the understanding for the operations of this faculty: 1. By the principle of

the homogeneity of the diverse in higher genera; 2. By the principle of the variety of the homogeneous in

lower species; and, to complete the systematic unity, it adds, 3. A law of the affinity of all conceptions which

prescribes a continuous transition from one species to every other by the gradual increase of diversity. We

may term these the principles of the homogeneity, the specification, and the continuity of forms. The latter

results from the union of the two former, inasmuch as we regard the systematic connection as complete in

thought, in the ascent to higher genera, as well as in the descent to lower species. For all diversities must be

related to each other, as they all spring from one highest genus, descending through the different gradations

We may illustrate the systematic unity produced by the three logical principles in the following manner.

Every conception may be regarded as a point, which, as the standpoint of a spectator, has a certain horizon,

which may be said to enclose a number of things that may be viewed, so to speak, from that centre. Within

this horizon there must be an infinite number of other points, each of which has its own horizon, smaller and

more circumscribed; in other words, every species contains subspecies, according to the principle of

specification, and the logical horizon consists of smaller horizons (subspecies), but not of points

(individuals), which possess no extent. But different horizons or genera, which include under them so many

conceptions, may have one common horizon, from which, as from a midpoint, they may be surveyed; and

we may proceed thus, till we arrive at the highest genus, or universal and true horizon, which is determined

by the highest conception, and which contains under itself all differences and varieties, as genera, species,

To this highest standpoint I am conducted by the law of homogeneity, as to all lower and more

variouslydetermined conceptions by the law of specification. Now as in this way there exists no void in the

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whole extent of all possible conceptions, and as out of the sphere of these the mind can discover nothing,

there arises from the presupposition of the universal horizon above mentioned, and its complete division, the

principle: Non datur vacuum formarum. This principle asserts that there are not different primitive and

highest genera, which stand isolated, so to speak, from each other, but all the various genera are mere

divisions and limitations of one highest and universal genus; and hence follows immediately the principle:

Datur continuum formarum. This principle indicates that all differences of species limit each other, and do

not admit of transition from one to another by a saltus, but only through smaller degrees of the difference

between the one species and the other. In one word, there are no species or subspecies which (in the view of

reason) are the nearest possible to each other; intermediate species or subspecies being always possible, the

difference of which from each of the former is always smaller than the difference existing between these.

The first law, therefore, directs us to avoid the notion that there exist different primal genera, and enounces

the fact of perfect homogeneity; the second imposes a check upon this tendency to unity and prescribes the

distinction of subspecies, before proceeding to apply our general conceptions to individuals. The third unites

both the former, by enouncing the fact of homogeneity as existing even in the most various diversity, by

means of the gradual transition from one species to another. Thus it indicates a relationship between the

But this logical law of the continuum specierum (formarum logicarum) presupposes a transcendental

principle (lex continui in natura), without which the understanding might be led into error, by following the

guidance of the former, and thus perhaps pursuing a path contrary to that prescribed by nature. This law must,

consequently, be based upon pure transcendental, and not upon empirical, considerations. For, in the latter

case, it would come later than the system; whereas it is really itself the parent of all that is systematic in our

cognition of nature. These principles are not mere hypotheses employed for the purpose of experimenting

upon nature; although when any such connection is discovered, it forms a solid ground for regarding the

hypothetical unity as valid in the sphere of nature and thus they are in this respect not without their use. But

we go farther, and maintain that it is manifest that these principles of parsimony in fundamental causes,

variety in effects, and affinity in phenomena, are in accordance both with reason and nature, and that they are

not mere methods or plans devised for the purpose of assisting us in our observation of the external world.

But it is plain that this continuity of forms is a mere idea, to which no adequate object can be discovered in

experience. And this for two reasons. First, because the species in nature are really divided, and hence form

quanta discreta; and, if the gradual progression through their affinity were continuous, the intermediate

members lying between two given species must be infinite in number, which is impossible. Secondly,

because we cannot make any determinate empirical use of this law, inasmuch as it does not present us with

any criterion of affinity which could aid us in determining how far we ought to pursue the graduation of

differences: it merely contains a general indication that it is our duty to seek for and, if possible, to discover

When we arrange these principles of systematic unity in the order conformable to their employment in

experience, they will stand thus: Variety, Affinity, Unity, each of them, as ideas, being taken in the highest

degree of their completeness. Reason presupposes the existence of cognitions of the understanding, which

have a direct relation to experience, and aims at the ideal unity of these cognitions a unity which far

transcends all experience or empirical notions. The affinity of the diverse, notwithstanding the differences

existing between its parts, has a relation to things, but a still closer one to the mere properties and powers of

things. For example, imperfect experience may represent the orbits of the planets as circular. But we discover

variations from this course, and we proceed to suppose that the planets revolve in a path which, if not a circle,

is of a character very similar to it. That is to say, the movements of those planets which do not form a circle

will approximate more or less to the properties of a circle, and probably form an ellipse. The paths of comets

exhibit still greater variations, for, so far as our observation extends, they do not return upon their own course

in a circle or ellipse. But we proceed to the conjecture that comets describe a parabola, a figure which is

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 217

closely allied to the ellipse. In fact, a parabola is merely an ellipse, with its longer axis produced to an

indefinite extent. Thus these principles conduct us to a unity in the genera of the forms of these orbits, and,

proceeding farther, to a unity as regards the cause of the motions of the heavenly bodies that is, gravitation.

But we go on extending our conquests over nature, and endeavour to explain all seeming deviations from

these rules, and even make additions to our system which no experience can ever substantiate for example,

the theory, in affinity with that of ellipses, of hyperbolic paths of comets, pursuing which, these bodies leave

our solar system and, passing from sun to sun, unite the most distant parts of the infinite universe, which is

The most remarkable circumstance connected with these principles is that they seem to be transcendental,

and, although only containing ideas for the guidance of the empirical exercise of reason, and although this

empirical employment stands to these ideas in an asymptotic relation alone (to use a mathematical term), that

is, continually approximate, without ever being able to attain to them, they possess, notwithstanding, as a

priori synthetical propositions, objective though undetermined validity, and are available as rules for possible

experience. In the elaboration of our experience, they may also be employed with great advantage, as

heuristic* principles. A transcendental deduction of them cannot be made; such a deduction being always

We distinguished, in the Transcendental Analytic, the dynamical principles of the understanding, which are

regulative principles of intuition, from the mathematical, which are constitutive principles of intuition. These

dynamical laws are, however, constitutive in relation to experience, inasmuch as they render the conceptions

without which experience could not exist possible a priori. But the principles of pure reason cannot be

constitutive even in regard to empirical conceptions, because no sensuous schema corresponding to them can

be discovered, and they cannot therefore have an object in concreto. Now, if I grant that they cannot be

employed in the sphere of experience, as constitutive principles, how shall I secure for them employment and

objective validity as regulative principles, and in what way can they be so employed?

The understanding is the object of reason, as sensibility is the object of the understanding. The production of

systematic unity in all the empirical operations of the understanding is the proper occupation of reason; just

as it is the business of the understanding to connect the various content of phenomena by means of

conceptions, and subject them to empirical laws. But the operations of the understanding are, without the

schemata of sensibility, undetermined; and, in the same manner, the unity of reason is perfectly undetermined

as regards the conditions under which, and the extent to which, the understanding ought to carry the

systematic connection of its conceptions. But, although it is impossible to discover in intuition a schema for

the complete systematic unity of all the conceptions of the understanding, there must be some analogon of

this schema. This analogon is the idea of the maximum of the division and the connection of our cognition in

one principle. For we may have a determinate notion of a maximum and an absolutely perfect, all the

restrictive conditions which are connected with an indeterminate and various content having been abstracted.

Thus the idea of reason is analogous with a sensuous schema, with this difference, that the application of the

categories to the schema of reason does not present a cognition of any object (as is the case with the

application of the categories to sensuous schemata), but merely provides us with a rule or principle for the

systematic unity of the exercise of the understanding. Now, as every principle which imposes upon the

exercise of the understanding a priori compliance with the rule of systematic unity also relates, although only

in an indirect manner, to an object of experience, the principles of pure reason will also possess objective

reality and validity in relation to experience. But they will not aim at determining our knowledge in regard to

any empirical object; they will merely indicate the procedure, following which the empirical and determinate

exercise of the understanding may be in complete harmony and connection with itself a result which is

produced by its being brought into harmony with the principle of systematic unity, so far as that is possible,

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I term all subjective principles, which are not derived from observation of the constitution of an object, but

from the interest which Reason has in producing a certain completeness in her cognition of that object,

maxims of reason. Thus there are maxims of speculative reason, which are based solely upon its speculative

When principles which are really regulative are regarded as constitutive, and employed as objective

principles, contradictions must arise; but if they are considered as mere maxims, there is no room for

contradictions of any kind, as they then merely indicate the different interests of reason, which occasion

differences in the mode of thought. In effect, Reason has only one single interest, and the seeming

contradiction existing between her maxims merely indicates a difference in, and a reciprocal limitation of, the

This reasoner has at heart the interest of diversity in accordance with the principle of specification; another,

the interest of unity in accordance with the principle of aggregation. Each believes that his judgement rests

upon a thorough insight into the subject he is examining, and yet it has been influenced solely by a greater or

less degree of adherence to some one of the two principles, neither of which are objective, but originate

solely from the interest of reason, and on this account to be termed maxims rather than principles. When I

observe intelligent men disputing about the distinctive characteristics of men, animals, or plants, and even of

minerals, those on the one side assuming the existence of certain national characteristics, certain

welldefined and hereditary distinctions of family, race, and so on, while the other side maintain that nature

has endowed all races of men with the same faculties and dispositions, and that all differences are but the

result of external and accidental circumstances I have only to consider for a moment the real nature of the

subject of discussion, to arrive at the conclusion that it is a subject far too deep for us to judge of, and that

there is little probability of either party being able to speak from a perfect insight into and understanding of

the nature of the subject itself. Both have, in reality, been struggling for the twofold interest of reason; the

one maintaining the one interest, the other the other. But this difference between the maxims of diversity and

unity may easily be reconciled and adjusted; although, so long as they are regarded as objective principles,

they must occasion not only contradictions and polemic, but place hinderances in the way of the advancement

of truth, until some means is discovered of reconciling these conflicting interests, and bringing reason into

The same is the case with the socalled law discovered by Leibnitz, and supported with remarkable ability by

Bonnet the law of the continuous gradation of created beings, which is nothing more than an inference from

the principle of affinity; for observation and study of the order of nature could never present it to the mind as

an objective truth. The steps of this ladder, as they appear in experience, are too far apart from each other,

and the socalled petty differences between different kinds of animals are in nature commonly so wide

separations that no confidence can be placed in such views (particularly when we reflect on the great variety

of things, and the ease with which we can discover resemblances), and no faith in the laws which are said to

express the aims and purposes of nature. On the other hand, the method of investigating the order of nature in

the light of this principle, and the maxim which requires us to regard this order it being still undetermined

how far it extends as really existing in nature, is beyond doubt a legitimate and excellent principle of

reason a principle which extends farther than any experience or observation of ours and which, without

giving us any positive knowledge of anything in the region of experience, guides us to the goal of systematic

The ideas of pure reason cannot be, of themselves and in their own nature, dialectical; it is from their

misemployment alone that fallacies and illusions arise. For they originate in the nature of reason itself, and it

is impossible that this supreme tribunal for all the rights and claims of speculation should be itself

undeserving of confidence and promotive of error. It is to be expected, therefore, that these ideas have a

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genuine and legitimate aim. It is true, the mob of sophists raise against reason the cry of inconsistency and

contradiction, and affect to despise the government of that faculty, because they cannot understand its

constitution, while it is to its beneficial influences alone that they owe the position and the intelligence which

We cannot employ an a priori conception with certainty, until we have made a transcendental deduction

therefore. The ideas of pure reason do not admit of the same kind of deduction as the categories. But if they

are to possess the least objective validity, and to represent anything but mere creations of thought (entia

rationis ratiocinantis), a deduction of them must be possible. This deduction will complete the critical task

imposed upon pure reason; and it is to this part Of our labours that we now proceed.

There is a great difference between a thing's being presented to the mind as an object in an absolute sense, or

merely as an ideal object. In the former case I employ my conceptions to determine the object; in the latter

case nothing is present to the mind but a mere schema, which does not relate directly to an object, not even in

a hypothetical sense, but which is useful only for the purpose of representing other objects to the mind, in a

mediate and indirect manner, by means of their relation to the idea in the intellect. Thus I say the conception

of a supreme intelligence is a mere idea; that is to say, its objective reality does not consist in the fact that it

has an immediate relation to an object (for in this sense we have no means of establishing its objective

validity), it is merely a schema constructed according to the necessary conditions of the unity of reason the

schema of a thing in general, which is useful towards the production of the highest degree of systematic unity

in the empirical exercise of reason, in which we deduce this or that object of experience from the imaginary

object of this idea, as the ground or cause of the said object of experience. In this way, the idea is properly a

heuristic, and not an ostensive, conception; it does not give us any information respecting the constitution of

an object, it merely indicates how, under the guidance of the idea, we ought to investigate the constitution and

the relations of objects in the world of experience. Now, if it can be shown that the three kinds of

transcendental ideas (psychological, cosmological, and theological), although not relating directly to any

object nor determining it, do nevertheless, on the supposition of the existence of an ideal object, produce

systematic unity in the laws of the empirical employment of the reason, and extend our empirical cognition,

without ever being inconsistent or in opposition with it it must be a necessary maxim of reason to regulate

its procedure according to these ideas. And this forms the transcendental deduction of all speculative ideas,

not as constitutive principles of the extension of our cognition beyond the limits of our experience, but as

regulative principles of the systematic unity of empirical cognition, which is by the aid of these ideas

arranged and emended within its own proper limits, to an extent unattainable by the operation of the

I shall make this plainer. Guided by the principles involved in these ideas, we must, in the first place, so

connect all the phenomena, actions, and feelings of the mind, as if it were a simple substance, which,

endowed with personal identity, possesses a permanent existence (in this life at least), while its states, among

which those of the body are to be included as external conditions, are in continual change. Secondly, in

cosmology, we must investigate the conditions of all natural phenomena, internal as well as external, as if

they belonged to a chain infinite and without any prime or supreme member, while we do not, on this

account, deny the existence of intelligible grounds of these phenomena, although we never employ them to

explain phenomena, for the simple reason that they are not objects of our cognition. Thirdly, in the sphere of

theology, we must regard the whole system of possible experience as forming an absolute, but dependent and

sensuouslyconditioned unity, and at the same time as based upon a sole, supreme, and allsufficient ground

existing apart from the world itself a ground which is a selfsubsistent, primeval and creative reason, in

relation to which we so employ our reason in the field of experience, as if all objects drew their origin from

that archetype of all reason. In other words, we ought not to deduce the internal phenomena of the mind from

a simple thinking substance, but deduce them from each other under the guidance of the regulative idea of a

simple being; we ought not to deduce the phenomena, order, and unity of the universe from a supreme

intelligence, but merely draw from this idea of a supremely wise cause the rules which must guide reason in

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Now there is nothing to hinder us from admitting these ideas to possess an objective and hyperbolic

existence, except the cosmological ideas, which lead reason into an antinomy: the psychological and

theological ideas are not antinomial. They contain no contradiction; and how, then, can any one dispute their

objective reality, since he who denies it knows as little about their possibility as we who affirm? And yet,

when we wish to admit the existence of a thing, it is not sufficient to convince ourselves that there is no

positive obstacle in the way; for it cannot be allowable to regard mere creations of thought, which transcend,

though they do not contradict, all our conceptions, as real and determinate objects, solely upon the authority

of a speculative reason striving to compass its own aims. They cannot, therefore, be admitted to be real in

themselves; they can only possess a comparative reality that of a schema of the regulative principle of the

systematic unity of all cognition. They are to be regarded not as actual things, but as in some measure

analogous to them. We abstract from the object of the idea all the conditions which limit the exercise of our

understanding, but which, on the other hand, are the sole conditions of our possessing a determinate

conception of any given thing. And thus we cogitate a something, of the real nature of which we have not the

least conception, but which we represent to ourselves as standing in a relation to the whole system of

By admitting these ideal beings, we do not really extend our cognitions beyond the objects of possible

experience; we extend merely the empirical unity of our experience, by the aid of systematic unity, the

schema of which is furnished by the idea, which is therefore valid not as a constitutive, but as a regulative

principle. For although we posit a thing corresponding to the idea a something, an actual existence we do

not on that account aim at the extension of our cognition by means of transcendent conceptions. This

existence is purely ideal, and not objective; it is the mere expression of the systematic unity which is to be the

guide of reason in the field of experience. There are no attempts made at deciding what the ground of this

Thus the transcendental and only determinate conception of God, which is presented to us by speculative

reason, is in the strictest sense deistic. In other words, reason does not assure us of the objective validity of

the conception; it merely gives us the idea of something, on which the supreme and necessary unity of all

experience is based. This something we cannot, following the analogy of a real substance, cogitate otherwise

than as the cause of all things operating in accordance with rational laws, if we regard it as an individual

object; although we should rest contented with the idea alone as a regulative principle of reason, and make no

attempt at completing the sum of the conditions imposed by thought. This attempt is, indeed, inconsistent

with the grand aim of complete systematic unity in the sphere of cognition a unity to which no bounds are

Hence it happens that, admitting a divine being, I can have no conception of the internal possibility of its

perfection, or of the necessity of its existence. The only advantage of this admission is that it enables me to

answer all other questions relating to the contingent, and to give reason the most complete satisfaction as

regards the unity which it aims at attaining in the world of experience. But I cannot satisfy reason with regard

to this hypothesis itself; and this proves that it is not its intelligence and insight into the subject, but its

speculative interest alone which induces it to proceed from a point lying far beyond the sphere of our

cognition, for the purpose of being able to consider all objects as parts of a systematic whole.

Here a distinction presents itself, in regard to the way in which we may cogitate a presupposition a

distinction which is somewhat subtle, but of great importance in transcendental philosophy. I may have

sufficient grounds to admit something, or the existence of something, in a relative point of view (suppositio

relativa), without being justified in admitting it in an absolute sense (suppositio absoluta). This distinction is

undoubtedly requisite, in the case of a regulative principle, the necessity of which we recognize, though we

are ignorant of the source and cause of that necessity, and which we assume to be based upon some ultimate

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ground, for the purpose of being able to cogitate the universality of the principle in a more determinate way.

For example, I cogitate the existence of a being corresponding to a pure transcendental idea. But I cannot

admit that this being exists absolutely and in itself, because all of the conceptions by which I can cogitate an

object in a determinate manner fall short of assuring me of its existence; nay, the conditions of the objective

validity of my conceptions are excluded by the idea by the very fact of its being an idea. The conceptions of

reality, substance, causality, nay, even that of necessity in existence, have no significance out of the sphere of

empirical cognition, and cannot, beyond that sphere, determine any object. They may, accordingly, be

employed to explain the possibility of things in the world of sense, but they are utterly inadequate to explain

the possibility of the universe itself considered as a whole; because in this case the ground of explanation

must lie out of and beyond the world, and cannot, therefore, be an object of possible experience. Now, I may

admit the existence of an incomprehensible being of this nature the object of a mere idea, relatively to the

world of sense; although I have no ground to admit its existence absolutely and in itself. For if an idea (that of

a systematic and complete unity, of which I shall presently speak more particularly) lies at the foundation of

the most extended empirical employment of reason, and if this idea cannot be adequately represented in

concreto, although it is indispensably necessary for the approximation of empirical unity to the highest

possible degree I am not only authorized, but compelled, to realize this idea, that is, to posit a real object

corresponding thereto. But I cannot profess to know this object; it is to me merely a something, to which, as

the ground of systematic unity in cognition, I attribute such properties as are analogous to the conceptions

employed by the understanding in the sphere of experience. Following the analogy of the notions of reality,

substance, causality, and necessity, I cogitate a being, which possesses all these attributes in the highest

degree; and, as this idea is the offspring of my reason alone, I cogitate this being as selfsubsistent reason,

and as the cause of the universe operating by means of ideas of the greatest possible harmony and unity. Thus

I abstract all conditions that would limit my idea, solely for the purpose of rendering systematic unity

possible in the world of empirical diversity, and thus securing the widest possible extension for the exercise

of reason in that sphere. This I am enabled to do, by regarding all connections and relations in the world of

sense, as if they were the dispositions of a supreme reason, of which our reason is but a faint image. I then

proceed to cogitate this Supreme Being by conceptions which have, properly, no meaning or application,

except in the world of sense. But as I am authorized to employ the transcendental hypothesis of such a being

in a relative respect alone, that is, as the substratum of the greatest possible unity in experience I may

attribute to a being which I regard as distinct from the world, such properties as belong solely to the sphere of

sense and experience. For I do not desire, and am not justified in desiring, to cognize this object of my idea,

as it exists in itself; for I possess no conceptions sufficient for or task, those of reality, substance, causality,

nay, even that of necessity in existence, losing all significance, and becoming merely the signs of

conceptions, without content and without applicability, when I attempt to carry them beyond the limits of the

world of sense. I cogitate merely the relation of a perfectly unknown being to the greatest possible systematic

unity of experience, solely for the purpose of employing it as the schema of the regulative principle which

It is evident, at the first view, that we cannot presuppose the reality of this transcendental object, by means of

the conceptions of reality, substance, causality, and so on, because these conceptions cannot be applied to

anything that is distinct from the world of sense. Thus the supposition of a Supreme Being or cause is purely

relative; it is cogitated only in behalf of the systematic unity of experience; such a being is but a something,

of whose existence in itself we have not the least conception. Thus, too, it becomes sufficiently manifest why

we required the idea of a necessary being in relation to objects given by sense, although we can never have

And now we can clearly perceive the result of our transcendental dialectic, and the proper aim of the ideas of

pure reason which become dialectical solely from misunderstanding and inconsiderateness. Pure reason is,

in fact, occupied with itself, and not with any object. Objects are not presented to it to be embraced in the

unity of an empirical conception; it is only the cognitions of the understanding that are presented to it, for the

purpose of receiving the unity of a rational conception, that is, of being connected according to a principle.

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 222

The unity of reason is the unity of system; and this systematic unity is not an objective principle, extending

its dominion over objects, but a subjective maxim, extending its authority over the empirical cognition of

objects. The systematic connection which reason gives to the empirical employment of the understanding not

only advances the extension of that employment, but ensures its correctness, and thus the principle of a

systematic unity of this nature is also objective, although only in an indefinite respect (principium vagum). It

is not, however, a constitutive principle, determining an object to which it directly relates; it is merely a

regulative principle or maxim, advancing and strengthening the empirical exercise of reason, by the opening

up of new paths of which the understanding is ignorant, while it never conflicts with the laws of its exercise

But reason cannot cogitate this systematic unity, without at the same time cogitating an object of the idea an

object that cannot be presented in any experience, which contains no concrete example of a complete

systematic unity. This being (ens rationis ratiocinatae) is therefore a mere idea and is not assumed to be a

thing which is real absolutely and in itself. On the contrary, it forms merely the problematical foundation of

the connection which the mind introduces among the phenomena of the sensuous world. We look upon this

connection, in the light of the abovementioned idea, as if it drew its origin from the supposed being which

corresponds to the idea. And yet all we aim at is the possession of this idea as a secure foundation for the

systematic unity of experience a unity indispensable to reason, advantageous to the understanding, and

We mistake the true meaning of this idea when we regard it as an enouncement, or even as a hypothetical

declaration of the existence of a real thing, which we are to regard as the origin or ground of a systematic

constitution of the universe. On the contrary, it is left completely undetermined what the nature or properties

of this socalled ground may be. The idea is merely to be adopted as a point of view, from which this unity,

so essential to reason and so beneficial to the understanding, may be regarded as radiating. In one word, this

transcendental thing is merely the schema of a regulative principle, by means of which Reason, so far as in

her lies, extends the dominion of systematic unity over the whole sphere of experience.

The first object of an idea of this kind is the ego, considered merely as a thinking nature or soul. If I wish to

investigate the properties of a thinking being, I must interrogate experience. But I find that I can apply none

of the categories to this object, the schema of these categories, which is the condition of their application,

being given only in sensuous intuition. But I cannot thus attain to the cognition of a systematic unity of all the

phenomena of the internal sense. Instead, therefore, of an empirical conception of what the soul really is,

reason takes the conception of the empirical unity of all thought, and, by cogitating this unity as

unconditioned and primitive, constructs the rational conception or idea of a simple substance which is in

itself unchangeable, possessing personal identity, and in connection with other real things external to it; in

one word, it constructs the idea of a simple selfsubsistent intelligence. But the real aim of reason in this

procedure is the attainment of principles of systematic unity for the explanation of the phenomena of the soul.

That is, reason desires to be able to represent all the determinations of the internal sense as existing in one

subject, all powers as deduced from one fundamental power, all changes as mere varieties in the condition of

a being which is permanent and always the same, and all phenomena in space as entirely different in their

nature from the procedure of thought. Essential simplicity (with the other attributes predicated of the ego) is

regarded as the mere schema of this regulative principle; it is not assumed that it is the actual ground of the

properties of the soul. For these properties may rest upon quite different grounds, of which we are completely

ignorant; just as the above predicates could not give us any knowledge of the soul as it is in itself, even if we

regarded them as valid in respect of it, inasmuch as they constitute a mere idea, which cannot be represented

in concreto. Nothing but good can result from a psychological idea of this kind, if we only take proper care

not to consider it as more than an idea; that is, if we regard it as valid merely in relation to the employment of

reason, in the sphere of the phenomena of the soul. Under the guidance of this idea, or principle, no empirical

laws of corporeal phenomena are called in to explain that which is a phenomenon of the internal sense alone;

no windy hypotheses of the generation, annihilation, and palingenesis of souls are admitted. Thus the

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consideration of this object of the internal sense is kept pure, and unmixed with heterogeneous elements;

while the investigation of reason aims at reducing all the grounds of explanation employed in this sphere of

knowledge to a single principle. All this is best effected, nay, cannot be effected otherwise than by means of

such a schema, which requires us to regard this ideal thing as an actual existence. The psychological idea is,

therefore, meaningless and inapplicable, except as the schema of a regulative conception. For, if I ask

whether the soul is not really of a spiritual nature it is a question which has no meaning. From such a

conception has been abstracted, not merely all corporeal nature, but all nature, that is, all the predicates of a

possible experience; and consequently, all the conditions which enable us to cogitate an object to this

conception have disappeared. But, if these conditions are absent, it is evident that the conception is

The second regulative idea of speculative reason is the conception of the universe. For nature is properly the

only object presented to us, in regard to which reason requires regulative principles. Nature is twofold

thinking and corporeal nature. To cogitate the latter in regard to its internal possibility, that is, to determine

the application of the categories to it, no idea is required no representation which transcends experience. In

this sphere, therefore, an idea is impossible, sensuous intuition being our only guide; while, in the sphere of

psychology, we require the fundamental idea (I), which contains a priori a certain form of thought namely,

the unity of the ego. Pure reason has, therefore, nothing left but nature in general, and the completeness of

conditions in nature in accordance with some principle. The absolute totality of the series of these conditions

is an idea, which can never be fully realized in the empirical exercise of reason, while it is serviceable as a

rule for the procedure of reason in relation to that totality. It requires us, in the explanation of given

phenomena (in the regress or ascent in the series), to proceed as if the series were infinite in itself, that is,

were prolonged in indefinitum,; while on the other hand, where reason is regarded as itself the determining

cause (in the region of freedom), we are required to proceed as if we had not before us an object of sense, but

of the pure understanding. In this latter case, the conditions do not exist in the series of phenomena, but may

be placed quite out of and beyond it, and the series of conditions may be regarded as if it had an absolute

beginning from an intelligible cause. All this proves that the cosmological ideas are nothing but regulative

principles, and not constitutive; and that their aim is not to realize an actual totality in such series. The full

discussion of this subject will be found in its proper place in the chapter on the antinomy of pure reason.

The third idea of pure reason, containing the hypothesis of a being which is valid merely as a relative

hypothesis, is that of the one and allsufficient cause of all cosmological series, in other words, the idea of

God. We have not the slightest ground absolutely to admit the existence of an object corresponding to this

idea; for what can empower or authorize us to affirm the existence of a being of the highest perfection a

being whose existence is absolutely necessary merely because we possess the conception of such a being?

The answer is: It is the existence of the world which renders this hypothesis necessary. But this answer makes

it perfectly evident that the idea of this being, like all other speculative ideas, is essentially nothing more than

a demand upon reason that it shall regulate the connection which it and its subordinate faculties introduce into

the phenomena of the world by principles of systematic unity and, consequently, that it shall regard all

phenomena as originating from one allembracing being, as the supreme and allsufficient cause. From this

it is plain that the only aim of reason in this procedure is the establishment of its own formal rule for the

extension of its dominion in the world of experience; that it does not aim at an extension of its cognition

beyond the limits of experience; and that, consequently, this idea does not contain any constitutive principle.

The highest formal unity, which is based upon ideas alone, is the unity of all things a unity in accordance

with an aim or purpose; and the speculative interest of reason renders it necessary to regard all order in the

world as if it originated from the intention and design of a supreme reason. This principle unfolds to the view

of reason in the sphere of experience new and enlarged prospects, and invites it to connect the phenomena of

the world according to teleological laws, and in this way to attain to the highest possible degree of systematic

unity. The hypothesis of a supreme intelligence, as the sole cause of the universe an intelligence which has

for us no more than an ideal existence is accordingly always of the greatest service to reason. Thus, if we

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presuppose, in relation to the figure of the earth (which is round, but somewhat flattened at the poles),* or

that of mountains or seas, wise designs on the part of an author of the universe, we cannot fail to make, by the

light of this supposition, a great number of interesting discoveries. If we keep to this hypothesis, as a

principle which is purely regulative, even error cannot be very detrimental. For, in this case, error can have

no more serious consequences than that, where we expected to discover a teleological connection (nexus

finalis), only a mechanical or physical connection appears. In such a case, we merely fail to find the

additional form of unity we expected, but we do not lose the rational unity which the mind requires in its

procedure in experience. But even a miscarriage of this sort cannot affect the law in its general and

teleological relations. For although we may convict an anatomist of an error, when he connects the limb of

some animal with a certain purpose, it is quite impossible to prove in a single case that any arrangement of

nature, be it what it may, is entirely without aim or design. And thus medical physiology, by the aid of a

principle presented to it by pure reason, extends its very limited empirical knowledge of the purposes of the

different parts of an organized body so far that it may be asserted with the utmost confidence, and with the

approbation of all reflecting men, that every organ or bodily part of an animal has its use and answers a

certain design. Now, this is a supposition which, if regarded as of a constitutive character, goes much farther

than any experience or observation of ours can justify. Hence it is evident that it is nothing more than a

regulative principle of reason, which aims at the highest degree of systematic unity, by the aid of the idea of a

causality according to design in a supreme cause a cause which it regards as the highest intelligence.

*The advantages which a circular form, in the case of the earth, has over every other, are well known. But

few are aware that the slight flattening at the poles, which gives it the figure of a spheroid, is the only cause

which prevents the elevations of continents or even of mountains, perhaps thrown up by some internal

convulsion, from continually altering the position of the axis of the earth and that to some considerable

degree in a short time. The great protuberance of the earth under the Equator serves to overbalance the

impetus of all other masses of earth, and thus to preserve the axis of the earth, so far as we can observe, in its

present position. And yet this wise arrangement has been unthinkingly explained from the equilibrium of the

If, however, we neglect this restriction of the idea to a purely regulative influence, reason is betrayed into

numerous errors. For it has then left the ground of experience, in which alone are to be found the criteria of

truth, and has ventured into the region of the incomprehensible and unsearchable, on the heights of which it

loses its power and collectedness, because it has completely severed its connection with experience.

The first error which arises from our employing the idea of a Supreme Being as a constitutive (in repugnance

to the very nature of an idea), and not as a regulative principle, is the error of inactive reason (ignava ratio).*

We may so term every principle which requires us to regard our investigations of nature as absolutely

complete, and allows reason to cease its inquiries, as if it had fully executed its task. Thus the psychological

idea of the ego, when employed as a constitutive principle for the explanation of the phenomena of the soul,

and for the extension of our knowledge regarding this subject beyond the limits of experience even to the

condition of the soul after death is convenient enough for the purposes of pure reason, but detrimental and

even ruinous to its interests in the sphere of nature and experience. The dogmatizing spiritualist explains the

unchanging unity of our personality through all changes of condition from the unity of a thinking substance,

the interest which we take in things and events that can happen only after our death, from a consciousness of

the immaterial nature of our thinking subject, and so on. Thus he dispenses with all empirical investigations

into the cause of these internal phenomena, and with all possible explanations of them upon purely natural

grounds; while, at the dictation of a transcendent reason, he passes by the immanent sources of cognition in

experience, greatly to his own ease and convenience, but to the sacrifice of all, genuine insight and

intelligence. These prejudicial consequences become still more evident, in the case of the dogmatical

treatment of our idea of a Supreme Intelligence, and the theological system of nature (physicotheology)

which is falsely based upon it. For, in this case, the aims which we observe in nature, and often those which

we merely fancy to exist, make the investigation of causes a very easy task, by directing us to refer such and

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 225

such phenomena immediately to the unsearchable will and counsel of the Supreme Wisdom, while we ought

to investigate their causes in the general laws of the mechanism of matter. We are thus recommended to

consider the labour of reason as ended, when we have merely dispensed with its employment, which is

guided surely and safely only by the order of nature and the series of changes in the world which are

arranged according to immanent and general laws. This error may be avoided, if we do not merely consider

from the viewpoint of final aims certain parts of nature, such as the division and structure of a continent, the

constitution and direction of certain mountainchains, or even the organization existing in the vegetable and

animal kingdoms, but look upon this systematic unity of nature in a perfectly general way, in relation to the

idea of a Supreme Intelligence. If we pursue this advice, we lay as a foundation for all investigation the

conformity to aims of all phenomena of nature in accordance with universal laws, for which no particular

arrangement of nature is exempt, but only cognized by us with more or less difficulty; and we possess a

regulative principle of the systematic unity of a teleological connection, which we do not attempt to anticipate

or predetermine. All that we do, and ought to do, is to follow out the physicomechanical connection in

nature according to general laws, with the hope of discovering, sooner or later, the teleological connection

also. Thus, and thus only, can the principle of final unity aid in the extension of the employment of reason in

the sphere of experience, without being in any case detrimental to its interests.

*This was the term applied by the old dialecticians to a sophistical argument, which ran thus: If it is your fate

to die of this disease, you will die, whether you employ a physician or not. Cicero says that this mode of

reasoning has received this appellation, because, if followed, it puts an end to the employment of reason in

the affairs of life. For a similar reason, I have applied this designation to the sophistical argument of pure

The second error which arises from the misconception of the principle of systematic unity is that of perverted

reason (perversa ratio, usteron roteron rationis). The idea of systematic unity is available as a regulative

principle in the connection of phenomena according to general natural laws; and, how far soever we have to

travel upon the path of experience to discover some fact or event, this idea requires us to believe that we have

approached all the more nearly to the completion of its use in the sphere of nature, although that completion

can never be attained. But this error reverses the procedure of reason. We begin by hypostatizing the principle

of systematic unity, and by giving an anthropomorphic determination to the conception of a Supreme

Intelligence, and then proceed forcibly to impose aims upon nature. Thus not only does teleology, which

ought to aid in the completion of unity in accordance with general laws, operate to the destruction of its

influence, but it hinders reason from attaining its proper aim, that is, the proof, upon natural grounds, of the

existence of a supreme intelligent cause. For, if we cannot presuppose supreme finality in nature a priori, that

is, as essentially belonging to nature, how can we be directed to endeavour to discover this unity and, rising

gradually through its different degrees, to approach the supreme perfection of an author of all a perfection

which is absolutely necessary, and therefore cognizable a priori? The regulative principle directs us to

presuppose systematic unity absolutely and, consequently, as following from the essential nature of things

but only as a unity of nature, not merely cognized empirically, but presupposed a priori, although only in an

indeterminate manner. But if I insist on basing nature upon the foundation of a supreme ordaining Being, the

unity of nature is in effect lost. For, in this case, it is quite foreign and unessential to the nature of things, and

cannot be cognized from the general laws of nature. And thus arises a vicious circular argument, what ought

To take the regulative principle of systematic unity in nature for a constitutive principle, and to hypostatize

and make a cause out of that which is properly the ideal ground of the consistent and harmonious exercise of

reason, involves reason in inextricable embarrassments. The investigation of nature pursues its own path

under the guidance of the chain of natural causes, in accordance with the general laws of nature, and ever

follows the light of the idea of an author of the universe not for the purpose of deducing the finality, which

it constantly pursues, from this Supreme Being, but to attain to the cognition of his existence from the finality

which it seeks in the existence of the phenomena of nature, and, if possible, in that of all things to cognize

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 226

this being, consequently, as absolutely necessary. Whether this latter purpose succeed or not, the idea is and

must always be a true one, and its employment, when merely regulative, must always be accompanied by

Complete unity, in conformity with aims, constitutes absolute perfection. But if we do not find this unity in

the nature of the things which go to constitute the world of experience, that is, of objective cognition,

consequently in the universal and necessary laws of nature, how can we infer from this unity the idea of the

supreme and absolutely necessary perfection of a primal being, which is the origin of all causality? The

greatest systematic unity, and consequently teleological unity, constitutes the very foundation of the

possibility of the most extended employment of human reason. The idea of unity is therefore essentially and

indissolubly connected with the nature of our reason. This idea is a legislative one; and hence it is very

natural that we should assume the existence of a legislative reason corresponding to it, from which the

systematic unity of nature the object of the operations of reason must be derived.

In the course of our discussion of the antinomies, we stated that it is always possible to answer all the

questions which pure reason may raise; and that the plea of the limited nature of our cognition, which is

unavoidable and proper in many questions regarding natural phenomena, cannot in this case be admitted,

because the questions raised do not relate to the nature of things, but are necessarily originated by the nature

of reason itself, and relate to its own internal constitution. We can now establish this assertion, which at first

sight appeared so rash, in relation to the two questions in which reason takes the greatest interest, and thus

If, then, the question is asked, in relation to transcendental theology,* first, whether there is anything distinct

from the world, which contains the ground of cosmical order and connection according to general laws? The

answer is: Certainly. For the world is a sum of phenomena; there must, therefore, be some transcendental

basis of these phenomena, that is, a basis cogitable by the pure understanding alone. If, secondly, the question

is asked whether this being is substance, whether it is of the greatest reality, whether it is necessary, and so

forth? I answer that this question is utterly without meaning. For all the categories which aid me in forming a

conception of an object cannot be employed except in the world of sense, and are without meaning when not

applied to objects of actual or possible experience. Out of this sphere, they are not properly conceptions, but

the mere marks or indices of conceptions, which we may admit, although they cannot, without the help of

experience, help us to understand any subject or thing. If, thirdly, the question is whether we may not cogitate

this being, which is distinct from the world, in analogy with the objects of experience? The answer is:

Undoubtedly, but only as an ideal, and not as a real object. That is, we must cogitate it only as an unknown

substratum of the systematic unity, order, and finality of the world a unity which reason must employ as the

regulative principle of its investigation of nature. Nay, more, we may admit into the idea certain

anthropomorphic elements, which are promotive of the interests of this regulative principle. For it is no more

than an idea, which does not relate directly to a being distinct from the world, but to the regulative principle

of the systematic unity of the world, by means, however, of a schema of this unity the schema of a Supreme

Intelligence, who is the wiselydesigning author of the universe. What this basis of cosmical unity may be in

itself, we know not we cannot discover from the idea; we merely know how we ought to employ the idea of

this unity, in relation to the systematic operation of reason in the sphere of experience.

*After what has been said of the psychological idea of the ego and its proper employment as a regulative

principle of the operations of reason, I need not enter into details regarding the transcendental illusion by

which the systematic unity of all the various phenomena of the internal sense is hypostatized. The procedure

is in this case very similar to that which has been discussed in our remarks on the theological ideal.

But, it will be asked again, can we on these grounds, admit the existence of a wise and omnipotent author of

the world? Without doubt; and not only so, but we must assume the existence of such a being. But do we thus

extend the limits of our knowledge beyond the field of possible experience? By no means. For we have

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merely presupposed a something, of which we have no conception, which we do not know as it is in itself;

but, in relation to the systematic disposition of the universe, which we must presuppose in all our observation

of nature, we have cogitated this unknown being in analogy with an intelligent existence (an empirical

conception), that is to say, we have endowed it with those attributes, which, judging from the nature of our

own reason, may contain the ground of such a systematic unity. This idea is therefore valid only relatively to

the employment in experience of our reason. But if we attribute to it absolute and objective validity, we

overlook the fact that it is merely an ideal being that we cogitate; and, by setting out from a basis which is not

determinable by considerations drawn from experience, we place ourselves in a position which incapacitates

But, it will be asked further, can I make any use of this conception and hypothesis in my investigations into

the world and nature? Yes, for this very purpose was the idea established by reason as a fundamental basis.

But may I regard certain arrangements, which seemed to have been made in conformity with some fixed aim,

as the arrangements of design, and look upon them as proceeding from the divine will, with the intervention,

however, of certain other particular arrangements disposed to that end? Yes, you may do so; but at the same

time you must regard it as indifferent, whether it is asserted that divine wisdom has disposed all things in

conformity with his highest aims, or that the idea of supreme wisdom is a regulative principle in the

investigation of nature, and at the same time a principle of the systematic unity of nature according to general

laws, even in those cases where we are unable to discover that unity. In other words, it must be perfectly

indifferent to you whether you say, when you have discovered this unity: God has wisely willed it so; or:

Nature has wisely arranged this. For it was nothing but the systematic unity, which reason requires as a basis

for the investigation of nature, that justified you in accepting the idea of a supreme intelligence as a schema

for a regulative principle; and, the farther you advance in the discovery of design and finality, the more

certain the validity of your idea. But, as the whole aim of this regulative principle was the discovery of a

necessary and systematic unity in nature, we have, in so far as we attain this, to attribute our success to the

idea of a Supreme Being; while, at the same time, we cannot, without involving ourselves in contradictions,

overlook the general laws of nature, as it was in reference to them alone that this idea was employed. We

cannot, I say, overlook the general laws of nature, and regard this conformity to aims observable in nature as

contingent or hyperphysical in its origin; inasmuch as there is no ground which can justify us in the

admission of a being with such properties distinct from and above nature. All that we are authorized to assert

is that this idea may be employed as a principle, and that the properties of the being which is assumed to

correspond to it may be regarded as systematically connected in analogy with the causal determination of

For the same reasons we are justified in introducing into the idea of the supreme cause other anthropomorphic

elements (for without these we could not predicate anything of it); we may regard it as allowable to cogitate

this cause as a being with understanding, the feelings of pleasure and displeasure, and faculties of desire and

will corresponding to these. At the same time, we may attribute to this being infinite perfection a perfection

which necessarily transcends that which our knowledge of the order and design in the world authorize us to

predicate of it. For the regulative law of systematic unity requires us to study nature on the supposition that

systematic and final unity in infinitum is everywhere discoverable, even in the highest diversity. For,

although we may discover little of this cosmical perfection, it belongs to the legislative prerogative of reason

to require us always to seek for and to expect it; while it must always be beneficial to institute all inquiries

into nature in accordance with this principle. But it is evident that, by this idea of a supreme author of all,

which I place as the foundation of all inquiries into nature, I do not mean to assert the existence of such a

being, or that I have any knowledge of its existence; and, consequently, I do not really deduce anything from

the existence of this being, but merely from its idea, that is to say, from the nature of things in this world, in

accordance with this idea. A certain dim consciousness of the true use of this idea seems to have dictated to

the philosophers of all times the moderate language used by them regarding the cause of the world. We find

them employing the expressions wisdom and care of nature, and divine wisdom, as synonymous nay, in

purely speculative discussions, preferring the former, because it does not carry the appearance of greater

SECTION VII. Critique of all Theology based upon Speculative Principles of Reason. 228

pretensions than such as we are entitled to make, and at the same time directs reason to its proper field of

Thus, pure reason, which at first seemed to promise us nothing less than the extension of our cognition

beyond the limits of experience, is found, when thoroughly examined, to contain nothing but regulative

principles, the virtue and function of which is to introduce into our cognition a higher degree of unity than the

understanding could of itself. These principles, by placing the goal of all our struggles at so great a distance,

realize for us the most thorough connection between the different parts of our cognition, and the highest

degree of systematic unity. But, on the other hand, if misunderstood and employed as constitutive principles

of transcendent cognition, they become the parents of illusions and contradictions, while pretending to

Thus all human cognition begins with intuitions, proceeds from thence to conceptions, and ends with ideas.

Although it possesses, in relation to all three elements, a priori sources of cognition, which seemed to

transcend the limits of all experience, a thoroughgoing criticism demonstrates that speculative reason can

never, by the aid of these elements, pass the bounds of possible experience, and that the proper destination of

this highest faculty of cognition is to employ all methods, and all the principles of these methods, for the

purpose of penetrating into the innermost secrets of nature, by the aid of the principles of unity (among all

kinds of which teleological unity is the highest), while it ought not to attempt to soar above the sphere of

experience, beyond which there lies nought for us but the void inane. The critical examination, in our

Transcendental Analytic, of all the propositions which professed to extend cognition beyond the sphere of

experience, completely demonstrated that they can only conduct us to a possible experience. If we were not

distrustful even of the clearest abstract theorems, if we were not allured by specious and inviting prospects to

escape from the constraining power of their evidence, we might spare ourselves the laborious examination of

all the dialectical arguments which a transcendent reason adduces in support of its pretensions; for we should

know with the most complete certainty that, however honest such professions might be, they are null and

valueless, because they relate to a kind of knowledge to which no man can by any possibility attain. But, as

there is no end to discussion, if we cannot discover the true cause of the illusions by which even the wisest

are deceived, and as the analysis of all our transcendent cognition into its elements is of itself of no slight

value as a psychological study, while it is a duty incumbent on every philosopher it was found necessary to

investigate the dialectical procedure of reason in its primary sources. And as the inferences of which this

dialectic is the parent are not only deceitful, but naturally possess a profound interest for humanity, it was

advisable at the same time, to give a full account of the momenta of this dialectical procedure, and to deposit

it in the archives of human reason, as a warning to all future metaphysicians to avoid these causes of

If we regard the sum of the cognition of pure speculative reason as an edifice, the idea of which, at least,

exists in the human mind, it may be said that we have in the Transcendental Doctrine of Elements examined

the materials and determined to what edifice these belong, and what its height and stability. We have found,

indeed, that, although we had purposed to build for ourselves a tower which should reach to Heaven, the

supply of materials sufficed merely for a habitation, which was spacious enough for all terrestrial purposes,

and high enough to enable us to survey the level plain of experience, but that the bold undertaking designed

necessarily failed for want of materials not to mention the confusion of tongues, which gave rise to endless

disputes among the labourers on the plan of the edifice, and at last scattered them over all the world, each to

erect a separate building for himself, according to his own plans and his own inclinations. Our present task

relates not to the materials, but to the plan of an edifice; and, as we have had sufficient warning not to venture

blindly upon a design which may be found to transcend our natural powers, while, at the same time, we

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cannot give up the intention of erecting a secure abode for the mind, we must proportion our design to the

material which is presented to us, and which is, at the same time, sufficient for all our wants.

I understand, then, by the transcendental doctrine of method, the determination of the formal conditions of a

complete system of pure reason. We shall accordingly have to treat of the discipline, the canon, the

architectonic, and, finally, the history of pure reason. This part of our Critique will accomplish, from the

transcendental point of view, what has been usually attempted, but miserably executed, under the name of

practical logic. It has been badly executed, I say, because general logic, not being limited to any particular

kind of cognition (not even to the pure cognition of the understanding) nor to any particular objects, it cannot,

without borrowing from other sciences, do more than present merely the titles or signs of possible methods

and the technical expressions, which are employed in the systematic parts of all sciences; and thus the pupil is

made acquainted with names, the meaning and application of which he is to learn only at some future time.

Negative judgements those which are so not merely as regards their logical form, but in respect of their

content are not commonly held in especial respect. They are, on the contrary, regarded as jealous enemies of

our insatiable desire for knowledge; and it almost requires an apology to induce us to tolerate, much less to

All propositions, indeed, may be logically expressed in a negative form; but, in relation to the content of our

cognition, the peculiar province of negative judgements is solely to prevent error. For this reason, too,

negative propositions, which are framed for the purpose of correcting false cognitions where error is

absolutely impossible, are undoubtedly true, but inane and senseless; that is, they are in reality purposeless

and, for this reason, often very ridiculous. Such is the proposition of the schoolman that Alexander could not

But where the limits of our possible cognition are very much contracted, the attraction to new fields of

knowledge great, the illusions to which the mind is subject of the most deceptive character, and the evil

consequences of error of no inconsiderable magnitude the negative element in knowledge, which is useful

only to guard us against error, is of far more importance than much of that positive instruction which makes

additions to the sum of our knowledge. The restraint which is employed to repress, and finally to extirpate the

constant inclination to depart from certain rules, is termed discipline. It is distinguished from culture, which

aims at the formation of a certain degree of skill, without attempting to repress or to destroy any other mental

power, already existing. In the cultivation of a talent, which has given evidence of an impulse towards

selfdevelopment, discipline takes a negative,* culture and doctrine a positive, part.

*I am well aware that, in the language of the schools, the term discipline is usually employed as synonymous

with instruction. But there are so many cases in which it is necessary to distinguish the notion of the former,

as a course of corrective training, from that of the latter, as the communication of knowledge, and the nature

of things itself demands the appropriation of the most suitable expressions for this distinction, that it is my

desire that the former terms should never be employed in any other than a negative signification.

That natural dispositions and talents (such as imagination and with, which ask a free and unlimited

development, require in many respects the corrective influence of discipline, every one will readily grant. But

it may well appear strange that reason, whose proper duty it is to prescribe rules of discipline to all the other

powers of the mind, should itself require this corrective. It has, in fact, hitherto escaped this humiliation, only

because, in presence of its magnificent pretensions and high position, no one could readily suspect it to be

Reason, when employed in the field of experience, does not stand in need of criticism, because its principles

are subjected to the continual test of empirical observations. Nor is criticism requisite in the sphere of

mathematics, where the conceptions of reason must always be presented in concreto in pure intuition, and

baseless or arbitrary assertions are discovered without difficulty. But where reason is not held in a plain track

by the influence of empirical or of pure intuition, that is, when it is employed in the transcendental sphere of

pure conceptions, it stands in great need of discipline, to restrain its propensity to overstep the limits of

possible experience and to keep it from wandering into error. In fact, the utility of the philosophy of pure

reason is entirely of this negative character. Particular errors may be corrected by particular animadversions,

and the causes of these errors may be eradicated by criticism. But where we find, as in the case of pure

reason, a complete system of illusions and fallacies, closely connected with each other and depending upon

grand general principles, there seems to be required a peculiar and negative code of mental legislation, which,

under the denomination of a discipline, and founded upon the nature of reason and the objects of its exercise,

shall constitute a system of thorough examination and testing, which no fallacy will be able to withstand or

But the reader must remark that, in this the second division of our transcendental Critique the discipline of

pure reason is not directed to the content, but to the method of the cognition of pure reason. The former task

has been completed in the doctrine of elements. But there is so much similarity in the mode of employing the

faculty of reason, whatever be the object to which it is applied, while, at the same time, its employment in the

transcendental sphere is so essentially different in kind from every other, that, without the warning negative

influence of a discipline specially directed to that end, the errors are unavoidable which spring from the

unskillful employment of the methods which are originated by reason but which are out of place in this

The science of mathematics presents the most brilliant example of the extension of the sphere of pure reason

without the aid of experience. Examples are always contagious; and they exert an especial influence on the

same faculty, which naturally flatters itself that it will have the same good fortune in other case as fell to its

lot in one fortunate instance. Hence pure reason hopes to be able to extend its empire in the transcendental

sphere with equal success and security, especially when it applies the same method which was attended with

such brilliant results in the science of mathematics. It is, therefore, of the highest importance for us to know

whether the method of arriving at demonstrative certainty, which is termed mathematical, be identical with

that by which we endeavour to attain the same degree of certainty in philosophy, and which is termed in that

Philosophical cognition is the cognition of reason by means of conceptions; mathematical cognition is

cognition by means of the construction of conceptions. The construction of a conception is the presentation a

priori of the intuition which corresponds to the conception. For this purpose a nonempirical intuition is

requisite, which, as an intuition, is an individual object; while, as the construction of a conception (a general

representation), it must be seen to be universally valid for all the possible intuitions which rank under that

conception. Thus I construct a triangle, by the presentation of the object which corresponds to this

conception, either by mere imagination, in pure intuition, or upon paper, in empirical intuition, in both cases

completely a priori, without borrowing the type of that figure from any experience. The individual figure

drawn upon paper is empirical; but it serves, notwithstanding, to indicate the conception, even in its

universality, because in this empirical intuition we keep our eye merely on the act of the construction of the

conception, and pay no attention to the various modes of determining it, for example, its size, the length of its

sides, the size of its angles, these not in the least affecting the essential character of the conception.

Philosophical cognition, accordingly, regards the particular only in the general; mathematical the general in

the particular, nay, in the individual. This is done, however, entirely a priori and by means of pure reason, so

that, as this individual figure is determined under certain universal conditions of construction, the object of

the conception, to which this individual figure corresponds as its schema, must be cogitated as universally

The essential difference of these two modes of cognition consists, therefore, in this formal quality; it does not

regard the difference of the matter or objects of both. Those thinkers who aim at distinguishing philosophy

from mathematics by asserting that the former has to do with quality merely, and the latter with quantity,

have mistaken the effect for the cause. The reason why mathematical cognition can relate only to quantity is

to be found in its form alone. For it is the conception of quantities only that is capable of being constructed,

that is, presented a priori in intuition; while qualities cannot be given in any other than an empirical intuition.

Hence the cognition of qualities by reason is possible only through conceptions. No one can find an intuition

which shall correspond to the conception of reality, except in experience; it cannot be presented to the mind a

priori and antecedently to the empirical consciousness of a reality. We can form an intuition, by means of the

mere conception of it, of a cone, without the aid of experience; but the colour of the cone we cannot know

except from experience. I cannot present an intuition of a cause, except in an example which experience

offers to me. Besides, philosophy, as well as mathematics, treats of quantities; as, for example, of totality,

infinity, and so on. Mathematics, too, treats of the difference of lines and surfaces as spaces of different

quality, of the continuity of extension as a quality thereof. But, although in such cases they have a common

object, the mode in which reason considers that object is very different in philosophy from what it is in

mathematics. The former confines itself to the general conceptions; the latter can do nothing with a mere

conception, it hastens to intuition. In this intuition it regards the conception in concreto, not empirically, but

in an a priori intuition, which it has constructed; and in which, all the results which follow from the general

conditions of the construction of the conception are in all cases valid for the object of the constructed

Suppose that the conception of a triangle is given to a philosopher and that he is required to discover, by the

philosophical method, what relation the sum of its angles bears to a right angle. He has nothing before him

but the conception of a figure enclosed within three right lines, and, consequently, with the same number of

angles. He may analyse the conception of a right line, of an angle, or of the number three as long as he

pleases, but he will not discover any properties not contained in these conceptions. But, if this question is

proposed to a geometrician, he at once begins by constructing a triangle. He knows that two right angles are

equal to the sum of all the contiguous angles which proceed from one point in a straight line; and he goes on

to produce one side of his triangle, thus forming two adjacent angles which are together equal to two right

angles. He then divides the exterior of these angles, by drawing a line parallel with the opposite side of the

triangle, and immediately perceives that be has thus got an exterior adjacent angle which is equal to the

interior. Proceeding in this way, through a chain of inferences, and always on the ground of intuition, he

But mathematics does not confine itself to the construction of quantities (quanta), as in the case of geometry;

it occupies itself with pure quantity also (quantitas), as in the case of algebra, where complete abstraction is

made of the properties of the object indicated by the conception of quantity. In algebra, a certain method of

notation by signs is adopted, and these indicate the different possible constructions of quantities, the

extraction of roots, and so on. After having thus denoted the general conception of quantities, according to

their different relations, the different operations by which quantity or number is increased or diminished are

presented in intuition in accordance with general rules. Thus, when one quantity is to be divided by another,

the signs which denote both are placed in the form peculiar to the operation of division; and thus algebra, by

means of a symbolical construction of quantity, just as geometry, with its ostensive or geometrical

construction (a construction of the objects themselves), arrives at results which discursive cognition cannot

Now, what is the cause of this difference in the fortune of the philosopher and the mathematician, the former

of whom follows the path of conceptions, while the latter pursues that of intuitions, which he represents, a

priori, in correspondence with his conceptions? The cause is evident from what has been already

demonstrated in the introduction to this Critique. We do not, in the present case, want to discover analytical

propositions, which may be produced merely by analysing our conceptions for in this the philosopher would

have the advantage over his rival; we aim at the discovery of synthetical propositions such synthetical

propositions, moreover, as can be cognized a priori. I must not confine myself to that which I actually

cogitate in my conception of a triangle, for this is nothing more than the mere definition; I must try to go

beyond that, and to arrive at properties which are not contained in, although they belong to, the conception.

Now, this is impossible, unless I determine the object present to my mind according to the conditions, either

of empirical, or of pure, intuition. In the former case, I should have an empirical proposition (arrived at by

actual measurement of the angles of the triangle), which would possess neither universality nor necessity; but

that would be of no value. In the latter, I proceed by geometrical construction, by means of which I collect, in

a pure intuition, just as I would in an empirical intuition, all the various properties which belong to the

schema of a triangle in general, and consequently to its conception, and thus construct synthetical

It would be vain to philosophize upon the triangle, that is, to reflect on it discursively; I should get no further

than the definition with which I had been obliged to set out. There are certainly transcendental synthetical

propositions which are framed by means of pure conceptions, and which form the peculiar distinction of

philosophy; but these do not relate to any particular thing, but to a thing in general, and enounce the

conditions under which the perception of it may become a part of possible experience. But the science of

mathematics has nothing to do with such questions, nor with the question of existence in any fashion; it is

concerned merely with the properties of objects in themselves, only in so far as these are connected with the

In the above example, we merely attempted to show the great difference which exists between the discursive

employment of reason in the sphere of conceptions, and its intuitive exercise by means of the construction of

conceptions. The question naturally arises: What is the cause which necessitates this twofold exercise of

reason, and how are we to discover whether it is the philosophical or the mathematical method which reason

All our knowledge relates, finally, to possible intuitions, for it is these alone that present objects to the mind.

An a priori or nonempirical conception contains either a pure intuition and in this case it can be

constructed; or it contains nothing but the synthesis of possible intuitions, which are not given a priori. In this

latter case, it may help us to form synthetical a priori judgements, but only in the discursive method, by

The only a priori intuition is that of the pure form of phenomena space and time. A conception of space and

time as quanta may be presented a priori in intuition, that is, constructed, either alone with their quality

(figure), or as pure quantity (the mere synthesis of the homogeneous), by means of number. But the matter of

phenomena, by which things are given in space and time, can be presented only in perception, a posteriori.

The only conception which represents a priori this empirical content of phenomena is the conception of a

thing in general; and the a priori synthetical cognition of this conception can give us nothing more than the

rule for the synthesis of that which may be contained in the corresponding a posteriori perception; it is utterly

inadequate to present an a priori intuition of the real object, which must necessarily be empirical.

Synthetical propositions, which relate to things in general, an a priori intuition of which is impossible, are

transcendental. For this reason transcendental propositions cannot be framed by means of the construction of

conceptions; they are a priori, and based entirely on conceptions themselves. They contain merely the rule, by

which we are to seek in the world of perception or experience the synthetical unity of that which cannot be

intuited a priori. But they are incompetent to present any of the conceptions which appear in them in an a

priori intuition; these can be given only a posteriori, in experience, which, however, is itself possible only

If we are to form a synthetical judgement regarding a conception, we must go beyond it, to the intuition in

which it is given. If we keep to what is contained in the conception, the judgement is merely analytical it is

merely an explanation of what we have cogitated in the conception. But I can pass from the conception to the

pure or empirical intuition which corresponds to it. I can proceed to examine my conception in concreto, and

to cognize, either a priori or a posterio, what I find in the object of the conception. The former a priori

cognition is rationalmathematical cognition by means of the construction of the conception; the latter a

posteriori cognition is purely empirical cognition, which does not possess the attributes of necessity and

universality. Thus I may analyse the conception I have of gold; but I gain no new information from this

analysis, I merely enumerate the different properties which I had connected with the notion indicated by the

word. My knowledge has gained in logical clearness and arrangement, but no addition has been made to it.

But if I take the matter which is indicated by this name, and submit it to the examination of my senses, I am

enabled to form several synthetical although still empirical propositions. The mathematical conception of a

triangle I should construct, that is, present a priori in intuition, and in this way attain to rationalsynthetical

cognition. But when the transcendental conception of reality, or substance, or power is presented to my mind,

I find that it does not relate to or indicate either an empirical or pure intuition, but that it indicates merely the

synthesis of empirical intuitions, which cannot of course be given a priori. The synthesis in such a conception

cannot proceed a priori without the aid of experience to the intuition which corresponds to the conception;

and, for this reason, none of these conceptions can produce a determinative synthetical proposition, they can

never present more than a principle of the synthesis* of possible empirical intuitions. A transcendental

proposition is, therefore, a synthetical cognition of reason by means of pure conceptions and the discursive

method, and it renders possible all synthetical unity in empirical cognition, though it cannot present us with

*In the case of the conception of cause, I do really go beyond the empirical conception of an event but not

to the intuition which presents this conception in concreto, but only to the timeconditions, which may be

found in experience to correspond to the conception. My procedure is, therefore, strictly according to

conceptions; I cannot in a case of this kind employ the construction of conceptions, because the conception is

merely a rule for the synthesis of perceptions, which are not pure intuitions, and which, therefore, cannot be

There is thus a twofold exercise of reason. Both modes have the properties of universality and an a priori

origin in common, but are, in their procedure, of widely different character. The reason of this is that in the

world of phenomena, in which alone objects are presented to our minds, there are two main elements the

form of intuition (space and time), which can be cognized and determined completely a priori, and the matter

or content that which is presented in space and time, and which, consequently, contains a something an

existence corresponding to our powers of sensation. As regards the latter, which can never be given in a

determinate mode except by experience, there are no a priori notions which relate to it, except the

undetermined conceptions of the synthesis of possible sensations, in so far as these belong (in a possible

experience) to the unity of consciousness. As regards the former, we can determine our conceptions a priori

in intuition, inasmuch as we are ourselves the creators of the objects of the conceptions in space and time

these objects being regarded simply as quanta. In the one case, reason proceeds according to conceptions and

can do nothing more than subject phenomena to these which can only be determined empirically, that is, a

posteriori in conformity, however, with those conceptions as the rules of all empirical synthesis. In the other

case, reason proceeds by the construction of conceptions; and, as these conceptions relate to an a priori

intuition, they may be given and determined in pure intuition a priori, and without the aid of empirical data.

The examination and consideration of everything that exists in space or time whether it is a quantum or not,

in how far the particular something (which fills space or time) is a primary substratum, or a mere

determination of some other existence, whether it relates to anything else either as cause or effect, whether

its existence is isolated or in reciprocal connection with and dependence upon others, the possibility of this

existence, its reality and necessity or opposites all these form part of the cognition of reason on the ground

of conceptions, and this cognition is termed philosophical. But to determine a priori an intuition in space (its

figure), to divide time into periods, or merely to cognize the quantity of an intuition in space and time, and to

determine it by number all this is an operation of reason by means of the construction of conceptions, and is

The success which attends the efforts of reason in the sphere of mathematics naturally fosters the expectation

that the same good fortune will be its lot, if it applies the mathematical method in other regions of mental

endeavour besides that of quantities. Its success is thus great, because it can support all its conceptions by a

priori intuitions and, in this way, make itself a master, as it were, over nature; while pure philosophy, with its

a priori discursive conceptions, bungles about in the world of nature, and cannot accredit or show any a priori

evidence of the reality of these conceptions. Masters in the science of mathematics are confident of the

success of this method; indeed, it is a common persuasion that it is capable of being applied to any subject of

human thought. They have hardly ever reflected or philosophized on their favourite science a task of great

difficulty; and the specific difference between the two modes of employing the faculty of reason has never

entered their thoughts. Rules current in the field of common experience, and which common sense stamps

everywhere with its approval, are regarded by them as axiomatic. From what source the conceptions of space

and time, with which (as the only primitive quanta) they have to deal, enter their minds, is a question which

they do not trouble themselves to answer; and they think it just as unnecessary to examine into the origin of

the pure conceptions of the understanding and the extent of their validity. All they have to do with them is to

employ them. In all this they are perfectly right, if they do not overstep the limits of the sphere of nature. But

they pass, unconsciously, from the world of sense to the insecure ground of pure transcendental conceptions

(instabilis tellus, innabilis unda), where they can neither stand nor swim, and where the tracks of their

footsteps are obliterated by time; while the march of mathematics is pursued on a broad and magnificent

highway, which the latest posterity shall frequent without fear of danger or impediment.

As we have taken upon us the task of determining, clearly and certainly, the limits of pure reason in the

sphere of transcendentalism, and as the efforts of reason in this direction are persisted in, even after the

plainest and most expressive warnings, hope still beckoning us past the limits of experience into the

splendours of the intellectual world it becomes necessary to cut away the last anchor of this fallacious and

fantastic hope. We shall, accordingly, show that the mathematical method is unattended in the sphere of

philosophy by the least advantage except, perhaps, that it more plainly exhibits its own inadequacy that

geometry and philosophy are two quite different things, although they go band in hand in hand in the field of

natural science, and, consequently, that the procedure of the one can never be imitated by the other.

The evidence of mathematics rests upon definitions, axioms, and demonstrations. I shall be satisfied with

showing that none of these forms can be employed or imitated in philosophy in the sense in which they are

understood by mathematicians; and that the geometrician, if he employs his method in philosophy, will

succeed only in building cardcastles, while the employment of the philosophical method in mathematics can

result in nothing but mere verbiage. The essential business of philosophy, indeed, is to mark out the limits of

the science; and even the mathematician, unless his talent is naturally circumscribed and limited to this

particular department of knowledge, cannot turn a deaf ear to the warnings of philosophy, or set himself

I. Of Definitions. A definition is, as the term itself indicates, the representation, upon primary grounds, of the

complete conception of a thing within its own limits.* Accordingly, an empirical conception cannot be

defined, it can only be explained. For, as there are in such a conception only a certain number of marks or

signs, which denote a certain class of sensuous objects, we can never be sure that we do not cogitate under

the word which indicates the same object, at one time a greater, at another a smaller number of signs. Thus,

one person may cogitate in his conception of gold, in addition to its properties of weight, colour, malleability,

that of resisting rust, while another person may be ignorant of this quality. We employ certain signs only so

long as we require them for the sake of distinction; new observations abstract some and add new ones, so that

an empirical conception never remains within permanent limits. It is, in fact, useless to define a conception of

this kind. If, for example, we are speaking of water and its properties, we do not stop at what we actually

think by the word water, but proceed to observation and experiment; and the word, with the few signs

attached to it, is more properly a designation than a conception of the thing. A definition in this case would

evidently be nothing more than a determination of the word. In the second place, no a priori conception, such

as those of substance, cause, right, fitness, and so on, can be defined. For I can never be sure, that the clear

representation of a given conception (which is given in a confused state) has been fully developed, until I

know that the representation is adequate with its object. But, inasmuch as the conception, as it is presented to

the mind, may contain a number of obscure representations, which we do not observe in our analysis,

although we employ them in our application of the conception, I can never be sure that my analysis is

complete, while examples may make this probable, although they can never demonstrate the fact. instead of

the word definition, I should rather employ the term exposition a more modest expression, which the critic

may accept without surrendering his doubts as to the completeness of the analysis of any such conception.

As, therefore, neither empirical nor a priori conceptions are capable of definition, we have to see whether the

only other kind of conceptions arbitrary conceptions can be subjected to this mental operation. Such a

conception can always be defined; for I must know thoroughly what I wished to cogitate in it, as it was I who

created it, and it was not given to my mind either by the nature of my understanding or by experience. At the

same time, I cannot say that, by such a definition, I have defined a real object. If the conception is based upon

empirical conditions, if, for example, I have a conception of a clock for a ship, this arbitrary conception does

not assure me of the existence or even of the possibility of the object. My definition of such a conception

would with more propriety be termed a declaration of a project than a definition of an object. There are no

other conceptions which can bear definition, except those which contain an arbitrary synthesis, which can be

constructed a priori. Consequently, the science of mathematics alone possesses definitions. For the object

here thought is presented a priori in intuition; and thus it can never contain more or less than the conception,

because the conception of the object has been given by the definition and primarily, that is, without deriving

the definition from any other source. Philosophical definitions are, therefore, merely expositions of given

conceptions, while mathematical definitions are constructions of conceptions originally formed by the mind

itself; the former are produced by analysis, the completeness of which is never demonstratively certain, the

latter by a synthesis. In a mathematical definition the conception is formed, in a philosophical definition it is

*The definition must describe the conception completely that is, omit none of the marks or signs of which it

composed; within its own limits, that is, it must be precise, and enumerate no more signs than belong to the

conception; and on primary grounds, that is to say, the limitations of the bounds of the conception must not

be deduced from other conceptions, as in this case a proof would be necessary, and the socalled definition

would be incapable of taking its place at the bead of all the judgements we have to form regarding an object.

(a) That we must not imitate, in philosophy, the mathematical usage of commencing with definitions except

by way of hypothesis or experiment. For, as all socalled philosophical definitions are merely analyses of

given conceptions, these conceptions, although only in a confused form, must precede the analysis; and the

incomplete exposition must precede the complete, so that we may be able to draw certain inferences from the

characteristics which an incomplete analysis has enabled us to discover, before we attain to the complete

exposition or definition of the conception. In one word, a full and clear definition ought, in philosophy, rather

to form the conclusion than the commencement of our labours.* In mathematics, on the contrary, we cannot

have a conception prior to the definition; it is the definition which gives us the conception, and it must for

*Philosophy abounds in faulty definitions, especially such as contain some of the elements requisite to form a

complete definition. If a conception could not be employed in reasoning before it had been defined, it would

fare ill with all philosophical thought. But, as incompletely defined conceptions may always be employed

without detriment to truth, so far as our analysis of the elements contained in them proceeds, imperfect

definitions, that is, propositions which are properly not definitions, but merely approximations thereto, may

be used with great advantage. In mathematics, definition belongs ad esse, in philosophy ad melius esse. It is a

difficult task to construct a proper definition. Jurists are still without a complete definition of the idea of right.

(b) Mathematical definitions cannot be erroneous. For the conception is given only in and through the

definition, and thus it contains only what has been cogitated in the definition. But although a definition

cannot be incorrect, as regards its content, an error may sometimes, although seldom, creep into the form.

This error consists in a want of precision. Thus the common definition of a circle that it is a curved line,

every point in which is equally distant from another point called the centre is faulty, from the fact that the

determination indicated by the word curved is superfluous. For there ought to be a particular theorem, which

may be easily proved from the definition, to the effect that every line, which has all its points at equal

distances from another point, must be a curved line that is, that not even the smallest part of it can be

straight. Analytical definitions, on the other hand, may be erroneous in many respects, either by the

introduction of signs which do not actually exist in the conception, or by wanting in that completeness which

forms the essential of a definition. In the latter case, the definition is necessarily defective, because we can

never be fully certain of the completeness of our analysis. For these reasons, the method of definition

2. Of Axioms. These, in so far as they are immediately certain, are a priori synthetical principles. Now, one

conception cannot be connected synthetically and yet immediately with another; because, if we wish to

proceed out of and beyond a conception, a third mediating cognition is necessary. And, as philosophy is a

cognition of reason by the aid of conceptions alone, there is to be found in it no principle which deserves to

be called an axiom. Mathematics, on the other hand, may possess axioms, because it can always connect the

predicates of an object a priori, and without any mediating term, by means of the construction of conceptions

in intuition. Such is the case with the proposition: Three points can always lie in a plane. On the other hand,

no synthetical principle which is based upon conceptions, can ever be immediately certain (for example, the

proposition: Everything that happens has a cause), because I require a mediating term to connect the two

conceptions of event and cause namely, the condition of timedetermination in an experience, and I cannot

cognize any such principle immediately and from conceptions alone. Discursive principles are, accordingly,

very different from intuitive principles or axioms. The former always require deduction, which in the case of

the latter may be altogether dispensed with. Axioms are, for this reason, always selfevident, while

philosophical principles, whatever may be the degree of certainty they possess, cannot lay any claim to such a

distinction. No synthetical proposition of pure transcendental reason can be so evident, as is often rashly

enough declared, as the statement, twice two are four. It is true that in the Analytic I introduced into the list of

principles of the pure understanding, certain axioms of intuition; but the principle there discussed was not

itself an axiom, but served merely to present the principle of the possibility of axioms in general, while it was

really nothing more than a principle based upon conceptions. For it is one part of the duty of transcendental

philosophy to establish the possibility of mathematics itself. Philosophy possesses, then, no axioms, and has

no right to impose its a priori principles upon thought, until it has established their authority and validity by a

3. Of Demonstrations. Only an apodeictic proof, based upon intuition, can be termed a demonstration.

Experience teaches us what is, but it cannot convince us that it might not have been otherwise. Hence a proof

upon empirical grounds cannot be apodeictic. A priori conceptions, in discursive cognition, can never

produce intuitive certainty or evidence, however certain the judgement they present may be. Mathematics

alone, therefore, contains demonstrations, because it does not deduce its cognition from conceptions, but

from the construction of conceptions, that is, from intuition, which can be given a priori in accordance with

conceptions. The method of algebra, in equations, from which the correct answer is deduced by reduction, is

a kind of construction not geometrical, but by symbols in which all conceptions, especially those of the

relations of quantities, are represented in intuition by signs; and thus the conclusions in that science are

secured from errors by the fact that every proof is submitted to ocular evidence. Philosophical cognition does

not possess this advantage, it being required to consider the general always in abstracto (by means of

conceptions), while mathematics can always consider it in concreto (in an individual intuition), and at the

same time by means of a priori representation, whereby all errors are rendered manifest to the senses. The

former discursive proofs ought to be termed acroamatic proofs, rather than demonstrations, as only words

are employed in them, while demonstrations proper, as the term itself indicates, always require a reference to

It follows from all these considerations that it is not consonant with the nature of philosophy, especially in the

sphere of pure reason, to employ the dogmatical method, and to adorn itself with the titles and insignia of

mathematical science. It does not belong to that order, and can only hope for a fraternal union with that

science. Its attempts at mathematical evidence are vain pretensions, which can only keep it back from its true

aim, which is to detect the illusory procedure of reason when transgressing its proper limits, and by fully

explaining and analysing our conceptions, to conduct us from the dim regions of speculation to the clear

region of modest selfknowledge. Reason must not, therefore, in its transcendental endeavours, look forward

with such confidence, as if the path it is pursuing led straight to its aim, nor reckon with such security upon

its premisses, as to consider it unnecessary to take a step back, or to keep a strict watch for errors, which,

overlooked in the principles, may be detected in the arguments themselves in which case it may be requisite

either to determine these principles with greater strictness, or to change them entirely.

I divide all apodeictic propositions, whether demonstrable or immediately certain, into dogmata and

mathemata. A direct synthetical proposition, based on conceptions, is a dogma; a proposition of the same

kind, based on the construction of conceptions, is a mathema. Analytical judgements do not teach us any

more about an object than what was contained in the conception we had of it; because they do not extend our

cognition beyond our conception of an object, they merely elucidate the conception. They cannot therefore be

with propriety termed dogmas. Of the two kinds of a priori synthetical propositions above mentioned, only

those which are employed in philosophy can, according to the general mode of speech, bear this name; those

of arithmetic or geometry would not be rightly so denominated. Thus the customary mode of speaking

confirms the explanation given above, and the conclusion arrived at, that only those judgements which are

based upon conceptions, not on the construction of conceptions, can be termed dogmatical.

Thus, pure reason, in the sphere of speculation, does not contain a single direct synthetical judgement based

upon conceptions. By means of ideas, it is, as we have shown, incapable of producing synthetical judgements,

which are objectively valid; by means of the conceptions of the understanding, it establishes certain

indubitable principles, not, however, directly on the basis of conceptions, but only indirectly by means of the

relation of these conceptions to something of a purely contingent nature, namely, possible experience. When

experience is presupposed, these principles are apodeictically certain, but in themselves, and directly, they

cannot even be cognized a priori. Thus the given conceptions of cause and event will not be sufficient for the

demonstration of the proposition: Every event has a cause. For this reason, it is not a dogma; although from

another point of view, that of experience, it is capable of being proved to demonstration. The proper term for

such a proposition is principle, and not theorem (although it does require to be proved), because it possesses

the remarkable peculiarity of being the condition of the possibility of its own ground of proof, that is,

experience, and of forming a necessary presupposition in all empirical observation.

If then, in the speculative sphere of pure reason, no dogmata are to be found; all dogmatical methods, whether

borrowed from mathematics, or invented by philosophical thinkers, are alike inappropriate and inefficient.

They only serve to conceal errors and fallacies, and to deceive philosophy, whose duty it is to see that reason

pursues a safe and straight path. A philosophical method may, however, be systematical. For our reason is,

subjectively considered, itself a system, and, in the sphere of mere conceptions, a system of investigation

according to principles of unity, the material being supplied by experience alone. But this is not the proper

place for discussing the peculiar method of transcendental philosophy, as our present task is simply to

examine whether our faculties are capable of erecting an edifice on the basis of pure reason, and how far they

Reason must be subject, in all its operations, to criticism, which must always be permitted to exercise its

functions without restraint; otherwise its interests are imperilled and its influence obnoxious to suspicion.

There is nothing, however useful, however sacred it may be, that can claim exemption from the searching

examination of this supreme tribunal, which has no respect of persons. The very existence of reason depends

upon this freedom; for the voice of reason is not that of a dictatorial and despotic power, it is rather like the

vote of the citizens of a free state, every member of which must have the privilege of giving free expression

But while reason can never decline to submit itself to the tribunal of criticism, it has not always cause to

dread the judgement of this court. Pure reason, however, when engaged in the sphere of dogmatism, is not so

thoroughly conscious of a strict observance of its highest laws, as to appear before a higher judicial reason

with perfect confidence. On the contrary, it must renounce its magnificent dogmatical pretensions in

Very different is the case when it has to defend itself, not before a judge, but against an equal. If dogmatical

assertions are advanced on the negative side, in opposition to those made by reason on the positive side, its

justification kat authrhopon is complete, although the proof of its propositions is kat aletheian unsatisfactory.

By the polemic of pure reason I mean the defence of its propositions made by reason, in opposition to the

dogmatical counterpropositions advanced by other parties. The question here is not whether its own

statements may not also be false; it merely regards the fact that reason proves that the opposite cannot be

established with demonstrative certainty, nor even asserted with a higher degree of probability. Reason does

not hold her possessions upon sufferance; for, although she cannot show a perfectly satisfactory title to them,

It is a melancholy reflection that reason, in its highest exercise, falls into an antithetic; and that the supreme

tribunal for the settlement of differences should not be at union with itself. It is true that we had to discuss the

question of an apparent antithetic, but we found that it was based upon a misconception. In conformity with

the common prejudice, phenomena were regarded as things in themselves, and thus an absolute completeness

in their synthesis was required in the one mode or in the other (it was shown to be impossible in both); a

demand entirely out of place in regard to phenomena. There was, then, no real selfcontradiction of reason in

the propositions: The series of phenomena given in themselves has an absolutely first beginning; and: This

series is absolutely and in itself without beginning. The two propositions are perfectly consistent with each

other, because phenomena as phenomena are in themselves nothing, and consequently the hypothesis that

But there are cases in which a similar misunderstanding cannot be provided against, and the dispute must

remain unsettled. Take, for example, the theistic proposition: There is a Supreme Being; and on the other

hand, the atheistic counterstatement: There exists no Supreme Being; or, in psychology: Everything that

thinks possesses the attribute of absolute and permanent unity, which is utterly different from the transitory

unity of material phenomena; and the counterproposition: The soul is not an immaterial unity, and its nature

is transitory, like that of phenomena. The objects of these questions contain no heterogeneous or

contradictory elements, for they relate to things in themselves, and not to phenomena. There would arise,

indeed, a real contradiction, if reason came forward with a statement on the negative side of these questions

alone. As regards the criticism to which the grounds of proof on the affirmative side must be subjected, it

may be freely admitted, without necessitating the surrender of the affirmative propositions, which have, at

least, the interest of reason in their favour an advantage which the opposite party cannot lay claim to.

I cannot agree with the opinion of several admirable thinkers Sulzer among the rest that, in spite of the

weakness of the arguments hitherto in use, we may hope, one day, to see sufficient demonstrations of the two

cardinal propositions of pure reason the existence of a Supreme Being, and the immortality of the soul. I am

certain, on the contrary, that this will never be the case. For on what ground can reason base such synthetical

propositions, which do not relate to the objects of experience and their internal possibility? But it is also

demonstratively certain that no one will ever be able to maintain the contrary with the least show of

probability. For, as he can attempt such a proof solely upon the basis of pure reason, he is bound to prove that

a Supreme Being, and a thinking subject in the character of a pure intelligence, are impossible. But where

will he find the knowledge which can enable him to enounce synthetical judgements in regard to things which

transcend the region of experience? We may, therefore, rest assured that the opposite never will be

demonstrated. We need not, then, have recourse to scholastic arguments; we may always admit the truth of

those propositions which are consistent with the speculative interests of reason in the sphere of experience,

and form, moreover, the only means of uniting the speculative with the practical interest. Our opponent, who

must not be considered here as a critic solely, we can be ready to meet with a non liquet which cannot fail to

disconcert him; while we cannot deny his right to a similar retort, as we have on our side the advantage of the

support of the subjective maxim of reason, and can therefore look upon all his sophistical arguments with

From this point of view, there is properly no antithetic of pure reason. For the only arena for such a struggle

would be upon the field of pure theology and psychology; but on this ground there can appear no combatant

whom we need to fear. Ridicule and boasting can be his only weapons; and these may be laughed at, as mere

child's play. This consideration restores to Reason her courage; for what source of confidence could be found,

if she, whose vocation it is to destroy error, were at variance with herself and without any reasonable hope of

Everything in nature is good for some purpose. Even poisons are serviceable; they destroy the evil effects of

other poisons generated in our system, and must always find a place in every complete pharmacopoeia. The

objections raised against the fallacies and sophistries of speculative reason, are objections given by the nature

of this reason itself, and must therefore have a destination and purpose which can only be for the good of

humanity. For what purpose has Providence raised many objects, in which we have the deepest interest, so far

above us, that we vainly try to cognize them with certainty, and our powers of mental vision are rather

excited than satisfied by the glimpses we may chance to seize? It is very doubtful whether it is for our benefit

to advance bold affirmations regarding subjects involved in such obscurity; perhaps it would even be

detrimental to our best interests. But it is undoubtedly always beneficial to leave the investigating, as well as

the critical reason, in perfect freedom, and permit it to take charge of its own interests, which are advanced as

much by its limitation, as by its extension of its views, and which always suffer by the interference of foreign

powers forcing it, against its natural tendencies, to bend to certain preconceived designs.

Allow your opponent to say what he thinks reasonable, and combat him only with the weapons of reason.

Have no anxiety for the practical interests of humanity these are never imperilled in a purely speculative

dispute. Such a dispute serves merely to disclose the antinomy of reason, which, as it has its source in the

nature of reason, ought to be thoroughly investigated. Reason is benefited by the examination of a subject on

both sides, and its judgements are corrected by being limited. It is not the matter that may give occasion to

dispute, but the manner. For it is perfectly permissible to employ, in the presence of reason, the language of a

firmly rooted faith, even after we have been obliged to renounce all pretensions to knowledge.

If we were to ask the dispassionate David Hume a philosopher endowed, in a degree that few are, with a

wellbalanced judgement: What motive induced you to spend so much labour and thought in undermining

the consoling and beneficial persuasion that reason is capable of assuring us of the existence, and presenting

us with a determinate conception of a Supreme Being? his answer would be: Nothing but the desire of

teaching reason to know its own powers better, and, at the same time, a dislike of the procedure by which that

faculty was compelled to support foregone conclusions, and prevented from confessing the internal

weaknesses which it cannot but feel when it enters upon a rigid selfexamination. If, on the other hand, we

were to ask Priestley a philosopher who had no taste for transcendental speculation, but was entirely

devoted to the principles of empiricism what his motives were for overturning those two main pillars of

religion the doctrines of the freedom of the will and the immortality of the soul (in his view the hope of a

future life is but the expectation of the miracle of resurrection) this philosopher, himself a zealous and pious

teacher of religion, could give no other answer than this: I acted in the interest of reason, which always

suffers, when certain objects are explained and judged by a reference to other supposed laws than those of

material nature the only laws which we know in a determinate manner. It would be unfair to decry the latter

philosopher, who endeavoured to harmonize his paradoxical opinions with the interests of religion, and to

undervalue an honest and reflecting man, because he finds himself at a loss the moment he has left the field

of natural science. The same grace must be accorded to Hume, a man not less welldisposed, and quite as

blameless in his moral character, and who pushed his abstract speculations to an extreme length, because, as

he rightly believed, the object of them lies entirely beyond the bounds of natural science, and within the

What is to be done to provide against the danger which seems in the present case to menace the best interests

of humanity? The course to be pursued in reference to this subject is a perfectly plain and natural one. Let

each thinker pursue his own path; if he shows talent, if be gives evidence of profound thought, in one word, if

he shows that he possesses the power of reasoning reason is always the gainer. If you have recourse to other

means, if you attempt to coerce reason, if you raise the cry of treason to humanity, if you excite the feelings

of the crowd, which can neither understand nor sympathize with such subtle speculations you will only

make yourselves ridiculous. For the question does not concern the advantage or disadvantage which we are

expected to reap from such inquiries; the question is merely how far reason can advance in the field of

speculation, apart from all kinds of interest, and whether we may depend upon the exertions of speculative

reason, or must renounce all reliance on it. Instead of joining the combatants, it is your part to be a tranquil

spectator of the struggle a laborious struggle for the parties engaged, but attended, in its progress as well as

in its result, with the most advantageous consequences for the interests of thought and knowledge. It is absurd

to expect to be enlightened by Reason, and at the same time to prescribe to her what side of the question she

must adopt. Moreover, reason is sufficiently held in check by its own power, the limits imposed on it by its

own nature are sufficient; it is unnecessary for you to place over it additional guards, as if its power were

dangerous to the constitution of the intellectual state. In the dialectic of reason there is no victory gained

The strife of dialectic is a necessity of reason, and we cannot but wish that it had been conducted long ere this

with that perfect freedom which ought to be its essential condition. In this case, we should have had at an

earlier period a matured and profound criticism, which must have put an end to all dialectical disputes, by

There is in human nature an unworthy propensity a propensity which, like everything that springs from

nature, must in its final purpose be conducive to the good of humanity to conceal our real sentiments, and to

give expression only to certain received opinions, which are regarded as at once safe and promotive of the

common good. It is true, this tendency, not only to conceal our real sentiments, but to profess those which

may gain us favour in the eyes of society, has not only civilized, but, in a certain measure, moralized us; as no

one can break through the outward covering of respectability, honour, and morality, and thus the

seeminglygood examples which we which we see around us form an excellent school for moral

improvement, so long as our belief in their genuineness remains unshaken. But this disposition to represent

ourselves as better than we are, and to utter opinions which are not our own, can be nothing more than a kind

of provisionary arrangement of nature to lead us from the rudeness of an uncivilized state, and to teach us

how to assume at least the appearance and manner of the good we see. But when true principles have been

developed, and have obtained a sure foundation in our habit of thought, this conventionalism must be

attacked with earnest vigour, otherwise it corrupts the heart, and checks the growth of good dispositions with

I am sorry to remark the same tendency to misrepresentation and hypocrisy in the sphere of speculative

discussion, where there is less temptation to restrain the free expression of thought. For what can be more

prejudicial to the interests of intelligence than to falsify our real sentiments, to conceal the doubts which we

feel in regard to our statements, or to maintain the validity of grounds of proof which we well know to be

insufficient? So long as mere personal vanity is the source of these unworthy artifices and this is generally

the case in speculative discussions, which are mostly destitute of practical interest, and are incapable of

complete demonstration the vanity of the opposite party exaggerates as much on the other side; and thus the

result is the same, although it is not brought about so soon as if the dispute had been conducted in a sincere

and upright spirit. But where the mass entertains the notion that the aim of certain subtle speculators is

nothing less than to shake the very foundations of public welfare and morality it seems not only prudent, but

even praise worthy, to maintain the good cause by illusory arguments, rather than to give to our supposed

opponents the advantage of lowering our declarations to the moderate tone of a merely practical conviction,

and of compelling us to confess our inability to attain to apodeictic certainty in speculative subjects. But we

ought to reflect that there is nothing, in the world more fatal to the maintenance of a good cause than deceit,

misrepresentation, and falsehood. That the strictest laws of honesty should be observed in the discussion of a

purely speculative subject is the least requirement that can be made. If we could reckon with security even

upon so little, the conflict of speculative reason regarding the important questions of God, immortality, and

freedom, would have been either decided long ago, or would very soon be brought to a conclusion. But, in

general, the uprightness of the defence stands in an inverse ratio to the goodness of the cause; and perhaps

more honesty and fairness are shown by those who deny than by those who uphold these doctrines.

I shall persuade myself, then, that I have readers who do not wish to see a righteous cause defended by unfair

arguments. Such will now recognize the fact that, according to the principles of this Critique, if we consider

not what is, but what ought to be the case, there can be really no polemic of pure reason. For how can two

persons dispute about a thing, the reality of which neither can present in actual or even in possible

experience? Each adopts the plan of meditating on his idea for the purpose of drawing from the idea, if he

can, what is more than the idea, that is, the reality of the object which it indicates. How shall they settle the

dispute, since neither is able to make his assertions directly comprehensible and certain, but must restrict

himself to attacking and confuting those of his opponent? All statements enounced by pure reason transcend

the conditions of possible experience, beyond the sphere of which we can discover no criterion of truth, while

they are at the same time framed in accordance with the laws of the understanding, which are applicable only

to experience; and thus it is the fate of all such speculative discussions that while the one party attacks the

The critique of pure reason may be regarded as the highest tribunal for all speculative disputes; for it is not

involved in these disputes, which have an immediate relation to certain objects and not to the laws of the

mind, but is instituted for the purpose of determining the rights and limits of reason.

Without the control of criticism, reason is, as it were, in a state of nature, and can only establish its claims and

assertions by war. Criticism, on the contrary, deciding all questions according to the fundamental laws of its

own institution, secures to us the peace of law and order, and enables us to discuss all differences in the more

tranquil manner of a legal process. In the former case, disputes are ended by victory, which both sides may

claim and which is followed by a hollow armistice; in the latter, by a sentence, which, as it strikes at the root

of all speculative differences, ensures to all concerned a lasting peace. The endless disputes of a dogmatizing

reason compel us to look for some mode of arriving at a settled decision by a critical investigation of reason

itself; just as Hobbes maintains that the state of nature is a state of injustice and violence, and that we must

leave it and submit ourselves to the constraint of law, which indeed limits individual freedom, but only that it

This freedom will, among other things, permit of our openly stating the difficulties and doubts which we are

ourselves unable to solve, without being decried on that account as turbulent and dangerous citizens. This

privilege forms part of the native rights of human reason, which recognizes no other judge than the universal

reason of humanity; and as this reason is the source of all progress and improvement, such a privilege is to be

held sacred and inviolable. It is unwise, moreover, to denounce as dangerous any bold assertions against, or

rash attacks upon, an opinion which is held by the largest and most moral class of the community; for that

would be giving them an importance which they do not deserve. When I hear that the freedom of the will, the

hope of a future life, and the existence of God have been overthrown by the arguments of some able writer, I

feel a strong desire to read his book; for I expect that he will add to my knowledge and impart greater

clearness and distinctness to my views by the argumentative power shown in his writings. But I am perfectly

certain, even before I have opened the book, that he has not succeeded in a single point, not because I believe

I am in possession of irrefutable demonstrations of these important propositions, but because this

transcendental critique, which has disclosed to me the power and the limits of pure reason, has fully

convinced me that, as it is insufficient to establish the affirmative, it is as powerless, and even more so, to

assure us of the truth of the negative answer to these questions. From what source does this freethinker

derive his knowledge that there is, for example, no Supreme Being? This proposition lies out of the field of

possible experience, and, therefore, beyond the limits of human cognition. But I would not read at, all the

answer which the dogmatical maintainer of the good cause makes to his opponent, because I know well

beforehand, that he will merely attack the fallacious grounds of his adversary, without being able to establish

his own assertions. Besides, a new illusory argument, in the construction of which talent and acuteness are

shown, is suggestive of new ideas and new trains of reasoning, and in this respect the old and everyday

sophistries are quite useless. Again, the dogmatical opponent of religion gives employment to criticism, and

enables us to test and correct its principles, while there is no occasion for anxiety in regard to the influence

But, it will be said, must we not warn the youth entrusted to academical care against such writings, must we

not preserve them from the knowledge of these dangerous assertions, until their judgement is ripened, or

rather until the doctrines which we wish to inculcate are so firmly rooted in their minds as to withstand all

attempts at instilling the contrary dogmas, from whatever quarter they may come?

If we are to confine ourselves to the dogmatical procedure in the sphere of pure reason, and find ourselves

unable to settle such disputes otherwise than by becoming a party in them, and setting counterassertions

against the statements advanced by our opponents, there is certainly no plan more advisable for the moment,

but, at the same time, none more absurd and inefficient for the future, than this retaining of the youthful mind

under guardianship for a time, and thus preserving it for so long at least from seduction into error. But

when, at a later period, either curiosity, or the prevalent fashion of thought places such writings in their

hands, will the socalled convictions of their youth stand firm? The young thinker, who has in his armoury

none but dogmatical weapons with which to resist the attacks of his opponent, and who cannot detect the

latent dialectic which lies in his own opinions as well as in those of the opposite party, sees the advance of

illusory arguments and grounds of proof which have the advantage of novelty, against as illusory grounds of

proof destitute of this advantage, and which, perhaps, excite the suspicion that the natural credulity of his

youth has been abused by his instructors. He thinks he can find no better means of showing that he has out

grown the discipline of his minority than by despising those wellmeant warnings, and, knowing no system

of thought but that of dogmatism, he drinks deep draughts of the poison that is to sap the principles in which

Exactly the opposite of the system here recommended ought to be pursued in academical instruction. This can

only be effected, however, by a thorough training in the critical investigation of pure reason. For, in order to

bring the principles of this critique into exercise as soon as possible, and to demonstrate their perfect even in

the presence of the highest degree of dialectical illusion, the student ought to examine the assertions made on

both sides of speculative questions step by step, and to test them by these principles. It cannot be a difficult

task for him to show the fallacies inherent in these propositions, and thus he begins early to feel his own

power of securing himself against the influence of such sophistical arguments, which must finally lose, for

him, all their illusory power. And, although the same blows which overturn the edifice of his opponent are as

fatal to his own speculative structures, if such he has wished to rear; he need not feel any sorrow in regard to

this seeming misfortune, as he has now before him a fair prospect into the practical region in which he may

There is, accordingly, no proper polemic in the sphere of pure reason. Both parties beat the air and fight with

their own shadows, as they pass beyond the limits of nature, and can find no tangible point of attack no firm

footing for their dogmatical conflict. Fight as vigorously as they may, the shadows which they hew down,

immediately start up again, like the heroes in Walhalla, and renew the bloodless and unceasing contest.

But neither can we admit that there is any proper sceptical employment of pure reason, such as might be

based upon the principle of neutrality in all speculative disputes. To excite reason against itself, to place

weapons in the hands of the party on the one side as well as in those of the other, and to remain an

undisturbed and sarcastic spectator of the fierce struggle that ensues, seems, from the dogmatical point of

view, to be a part fitting only a malevolent disposition. But, when the sophist evidences an invincible

obstinacy and blindness, and a pride which no criticism can moderate, there is no other practicable course

than to oppose to this pride and obstinacy similar feelings and pretensions on the other side, equally well or

ill founded, so that reason, staggered by the reflections thus forced upon it, finds it necessary to moderate its

confidence in such pretensions and to listen to the advice of criticism. But we cannot stop at these doubts,

much less regard the conviction of our ignorance, not only as a cure for the conceit natural to dogmatism, but

as the settlement of the disputes in which reason is involved with itself. On the contrary, scepticism is merely

a means of awakening reason from its dogmatic dreams and exciting it to a more careful investigation into its

own powers and pretensions. But, as scepticism appears to be the shortest road to a permanent peace in the

domain of philosophy, and as it is the track pursued by the many who aim at giving a philosophical colouring

to their contemptuous dislike of all inquiries of this kind, I think it necessary to present to my readers this

The consciousness of ignorance unless this ignorance is recognized to be absolutely necessary ought,

instead of forming the conclusion of my inquiries, to be the strongest motive to the pursuit of them. All

ignorance is either ignorance of things or of the limits of knowledge. If my ignorance is accidental and not

necessary, it must incite me, in the first case, to a dogmatical inquiry regarding the objects of which I am

ignorant; in the second, to a critical investigation into the bounds of all possible knowledge. But that my

ignorance is absolutely necessary and unavoidable, and that it consequently absolves from the duty of all

further investigation, is a fact which cannot be made out upon empirical grounds from observation but

upon critical grounds alone, that is, by a thoroughgoing investigation into the primary sources of cognition. It

follows that the determination of the bounds of reason can be made only on a priori grounds; while the

empirical limitation of reason, which is merely an indeterminate cognition of an ignorance that can never be

completely removed, can take place only a posteriori. In other words, our empirical knowledge is limited by

that which yet remains for us to know. The former cognition of our ignorance, which is possible only on a

rational basis, is a science; the latter is merely a perception, and we cannot say how far the inferences drawn

from it may extend. If I regard the earth, as it really appears to my senses, as a flat surface, I am ignorant how

far this surface extends. But experience teaches me that, how far soever I go, I always see before me a space

in which I can proceed farther; and thus I know the limits merely visual of my actual knowledge of the

earth, although I am ignorant of the limits of the earth itself. But if I have got so far as to know that the earth

is a sphere, and that its surface is spherical, I can cognize a priori and determine upon principles, from my

knowledge of a small part of this surface say to the extent of a degree the diameter and circumference of

the earth; and although I am ignorant of the objects which this surface contains, I have a perfect knowledge of

The sum of all the possible objects of our cognition seems to us to be a level surface, with an apparent

horizon that which forms the limit of its extent, and which has been termed by us the idea of unconditioned

totality. To reach this limit by empirical means is impossible, and all attempts to determine it a priori

according to a principle, are alike in vain. But all the questions raised by pure reason relate to that which lies

The celebrated David Hume was one of those geographers of human reason who believe that they have given

a sufficient answer to all such questions by declaring them to lie beyond the horizon of our knowledge a

horizon which, however, Hume was unable to determine. His attention especially was directed to the

principle of causality; and he remarked with perfect justice that the truth of this principle, and even the

objective validity of the conception of a cause, was not commonly based upon clear insight, that is, upon a

priori cognition. Hence he concluded that this law does not derive its authority from its universality and

necessity, but merely from its general applicability in the course of experience, and a kind of subjective

necessity thence arising, which he termed habit. From the inability of reason to establish this principle as a

necessary law for the acquisition of all experience, he inferred the nullity of all the attempts of reason to pass

This procedure of subjecting the facta of reason to examination, and, if necessary, to disapproval, may be

termed the censura of reason. This censura must inevitably lead us to doubts regarding all transcendent

employment of principles. But this is only the second step in our inquiry. The first step in regard to the

subjects of pure reason, and which marks the infancy of that faculty, is that of dogmatism. The second, which

we have just mentioned, is that of scepticism, and it gives evidence that our judgement has been improved by

experience. But a third step is necessary indicative of the maturity and manhood of the judgement, which

now lays a firm foundation upon universal and necessary principles. This is the period of criticism, in which

we do not examine the facta of reason, but reason itself, in the whole extent of its powers, and in regard to its

capability of a priori cognition; and thus we determine not merely the empirical and evershifting bounds of

our knowledge, but its necessary and eternal limits. We demonstrate from indubitable principles, not merely

our ignorance in respect to this or that subject, but in regard to all possible questions of a certain class. Thus

scepticism is a resting place for reason, in which it may reflect on its dogmatical wanderings and gain some

knowledge of the region in which it happens to be, that it may pursue its way with greater certainty; but it

cannot be its permanent dwellingplace. It must take up its abode only in the region of complete certitude,

whether this relates to the cognition of objects themselves, or to the limits which bound all our cognition.

Reason is not to be considered as an indefinitely extended plane, of the bounds of which we have only a

general knowledge; it ought rather to be compared to a sphere, the radius of which may be found from the

curvature of its surface that is, the nature of a priori synthetical propositions and, consequently, its

circumference and extent. Beyond the sphere of experience there are no objects which it can cognize; nay,

even questions regarding such supposititious objects relate only to the subjective principles of a complete

determination of the relations which exist between the understandingconceptions which lie within this

We are actually in possession of a priori synthetical cognitions, as is proved by the existence of the principles

of the understanding, which anticipate experience. If any one cannot comprehend the possibility of these

principles, he may have some reason to doubt whether they are really a priori; but he cannot on this account

declare them to be impossible, and affirm the nullity of the steps which reason may have taken under their

guidance. He can only say: If we perceived their origin and their authenticity, we should be able to determine

the extent and limits of reason; but, till we can do this, all propositions regarding the latter are mere random

assertions. In this view, the doubt respecting all dogmatical philosophy, which proceeds without the guidance

of criticism, is well grounded; but we cannot therefore deny to reason the ability to construct a sound

philosophy, when the way has been prepared by a thorough critical investigation. All the conceptions

produced, and all the questions raised, by pure reason, do not lie in the sphere of experience, but in that of

reason itself, and hence they must be solved, and shown to be either valid or inadmissible, by that faculty. We

have no right to decline the solution of such problems, on the ground that the solution can be discovered only

from the nature of things, and under pretence of the limitation of human faculties, for reason is the sole

creator of all these ideas, and is therefore bound either to establish their validity or to expose their illusory

The polemic of scepticism is properly directed against the dogmatist, who erects a system of philosophy

without having examined the fundamental objective principles on which it is based, for the purpose of

evidencing the futility of his designs, and thus bringing him to a knowledge of his own powers. But, in itself,

scepticism does not give us any certain information in regard to the bounds of our knowledge. All

unsuccessful dogmatical attempts of reason are facia, which it is always useful to submit to the censure of the

sceptic. But this cannot help us to any decision regarding the expectations which reason cherishes of better

success in future endeavours; the investigations of scepticism cannot, therefore, settle the dispute regarding

Hume is perhaps the ablest and most ingenious of all sceptical philosophers, and his writings have,

undoubtedly, exerted the most powerful influence in awakening reason to a thorough investigation into its

own powers. It will, therefore, well repay our labours to consider for a little the course of reasoning which he

followed and the errors into which he strayed, although setting out on the path of truth and certitude.

Hume was probably aware, although he never clearly developed the notion, that we proceed in judgements of

a certain class beyond our conception if the object. I have termed this kind of judgement synthetical. As

regard the manner in which I pass beyond my conception by the aid of experience, no doubts can be

entertained. Experience is itself a synthesis of perceptions; and it employs perceptions to increment the

conception, which I obtain by means of another perception. But we feel persuaded that we are able to proceed

beyond a conception, and to extend our cognition a priori. We attempt this in two ways either, through the

pure understanding, in relation to that which may become an object of experience, or, through pure reason, in

relation to such properties of things, or of the existence of things, as can never be presented in any

experience. This sceptical philosopher did not distinguish these two kinds of judgements, as he ought to have

done, but regarded this augmentation of conceptions, and, if we may so express ourselves, the spontaneous

generation of understanding and reason, independently of the impregnation of experience, as altogether

impossible. The socalled a priori principles of these faculties he consequently held to be invalid and

imaginary, and regarded them as nothing but subjective habits of thought originating in experience, and

therefore purely empirical and contingent rules, to which we attribute a spurious necessity and universality. In

support of this strange assertion, he referred us to the generally acknowledged principle of the relation

between cause and effect. No faculty of the mind can conduct us from the conception of a thing to the

existence of something else; and hence he believed he could infer that, without experience, we possess no

source from which we can augment a conception, and no ground sufficient to justify us in framing a

judgement that is to extend our cognition a priori. That the light of the sun, which shines upon a piece of wax,

at the same time melts it, while it hardens clay, no power of the understanding could infer from the

conceptions which we previously possessed of these substances; much less is there any a priori law that could

conduct us to such a conclusion, which experience alone can certify. On the other hand, we have seen in our

discussion of transcendental logic, that, although we can never proceed immediately beyond the content of

the conception which is given us, we can always cognize completely a priori in relation, however, to a third

term, namely, possible experience the law of its connection with other things. For example, if I observe that

a piece of wax melts, I can cognize a priori that there must have been something (the sun's heat) preceding,

which this law; although, without the aid of experience, I could not cognize a priori and in a determinate

manner either the cause from the effect, or the effect from the cause. Hume was, therefore, wrong in

inferring, from the contingency of the determination according to law, the contingency of the law itself; and

the passing beyond the conception of a thing to possible experience (which is an a priori proceeding,

constituting the objective reality of the conception), he confounded with our synthesis of objects in actual

experience, which is always, of course, empirical. Thus, too, he regarded the principle of affinity, which has

its seat in the understanding and indicates a necessary connection, as a mere rule of association, lying in the

imitative faculty of imagination, which can present only contingent, and not objective connections.

The sceptical errors of this remarkably acute thinker arose principally from a defect, which was common to

him with the dogmatists, namely, that he had never made a systematic review of all the different kinds of a

priori synthesis performed by the understanding. Had he done so, he would have found, to take one example

among many, that the principle of permanence was of this character, and that it, as well as the principle of

causality, anticipates experience. In this way he might have been able to describe the determinate limits of the

a priori operations of understanding and reason. But he merely declared the understanding to be limited,

instead of showing what its limits were; he created a general mistrust in the power of our faculties, without

giving us any determinate knowledge of the bounds of our necessary and unavoidable ignorance; he

examined and condemned some of the principles of the understanding, without investigating all its powers

with the completeness necessary to criticism. He denies, with truth, certain powers to the understanding, but

he goes further, and declares it to be utterly inadequate to the a priori extension of knowledge, although he

has not fully examined all the powers which reside in the faculty; and thus the fate which always overtakes

scepticism meets him too. That is to say, his own declarations are doubted, for his objections were based

upon facta, which are contingent, and not upon principles, which can alone demonstrate the necessary

As Hume makes no distinction between the wellgrounded claims of the understanding and the dialectical

pretensions of reason, against which, however, his attacks are mainly directed, reason does not feel itself shut

out from all attempts at the extension of a priori cognition, and hence it refuses, in spite of a few checks in

this or that quarter, to relinquish such efforts. For one naturally arms oneself to resist an attack, and becomes

more obstinate in the resolve to establish the claims he has advanced. But a complete review of the powers of

reason, and the conviction thence arising that we are in possession of a limited field of action, while we must

admit the vanity of higher claims, puts an end to all doubt and dispute, and induces reason to rest satisfied

To the uncritical dogmatist, who has not surveyed the sphere of his understanding, nor determined, in

accordance with principles, the limits of possible cognition, who, consequently, is ignorant of his own

powers, and believes he will discover them by the attempts he makes in the field of cognition, these attacks of

scepticism are not only dangerous, but destructive. For if there is one proposition in his chain of reasoning

which be he cannot prove, or the fallacy in which be cannot evolve in accordance with a principle, suspicion

And thus scepticism, the bane of dogmatical philosophy, conducts us to a sound investigation into the

understanding and the reason. When we are thus far advanced, we need fear no further attacks; for the limits

of our domain are clearly marked out, and we can make no claims nor become involved in any disputes

regarding the region that lies beyond these limits. Thus the sceptical procedure in philosophy does not present

any solution of the problems of reason, but it forms an excellent exercise for its powers, awakening its

circumspection, and indicating the means whereby it may most fully establish its claims to its legitimate

This critique of reason has now taught us that all its efforts to extend the bounds of knowledge, by means of

pure speculation, are utterly fruitless. So much the wider field, it may appear, lies open to hypothesis; as,

where we cannot know with certainty, we are at liberty to make guesses and to form suppositions.

Imagination may be allowed, under the strict surveillance of reason, to invent suppositions; but, these must be

based on something that is perfectly certain and that is the possibility of the object. If we are well assured

upon this point, it is allowable to have recourse to supposition in regard to the reality of the object; but this

supposition must, unless it is utterly groundless, be connected, as its ground of explanation, with that which is

It is beyond our power to form the least conception a priori of the possibility of dynamical connection in

phenomena; and the category of the pure understanding will not enable us to ex. cogitate any such

connection, but merely helps us to understand it, when we meet with it in experience. For this reason we

cannot, in accordance with the categories, imagine or invent any object or any property of an object not

given, or that may not be given in experience, and employ it in a hypothesis; otherwise, we should be basing

our chain of reasoning upon mere chimerical fancies, and not upon conceptions of things. Thus, we have no

right to assume the existence of new powers, not existing in nature for example, an understanding with a

nonsensuous intuition, a force of attraction without contact, or some new kind of substances occupying

space, and yet without the property of impenetrability and, consequently, we cannot assume that there is any

other kind of community among substances than that observable in experience, any kind of presence than that

in space, or any kind of duration than that in time. In one word, the conditions of possible experience are for

reason the only conditions of the possibility of things; reason cannot venture to form, independently of these

conditions, any conceptions of things, because such conceptions, although not selfcontradictory, are without

The conceptions of reason are, as we have already shown, mere ideas, and do not relate to any object in any

kind of experience. At the same time, they do not indicate imaginary or possible objects. They are purely

problematical in their nature and, as aids to the heuristic exercise of the faculties, form the basis of the

regulative principles for the systematic employment of the understanding in the field of experience. If we

leave this ground of experience, they become mere fictions of thought, the possibility of which is quite

indemonstrable; and they cannot, consequently, be employed as hypotheses in the explanation of real

phenomena. It is quite admissible to cogitate the soul as simple, for the purpose of enabling ourselves to

employ the idea of a perfect and necessary unity of all the faculties of the mind as the principle of all our

inquiries into its internal phenomena, although we cannot cognize this unity in concreto. But to assume that

the soul is a simple substance (a transcendental conception) would be enouncing a proposition which is not

only indemonstrable as many physical hypotheses are but a proposition which is purely arbitrary, and in

the highest degree rash. The simple is never presented in experience; and, if by substance is here meant the

permanent object of sensuous intuition, the possibility of a simple phenomenon is perfectly inconceivable.

Reason affords no good grounds for admitting the existence of intelligible beings, or of intelligible properties

of sensuous things, although as we have no conception either of their possibility or of their impossibility it

will always be out of our power to affirm dogmatically that they do not exist. In the explanation of given

phenomena, no other things and no other grounds of explanation can be employed than those which stand in

connection with the given phenomena according to the known laws of experience. A transcendental

hypothesis, in which a mere idea of reason is employed to explain the phenomena of nature, would not give

us any better insight into a phenomenon, as we should be trying to explain what we do not sufficiently

understand from known empirical principles, by what we do not understand at all. The principles of such a

hypothesis might conduce to the satisfaction of reason, but it would not assist the understanding in its

application to objects. Order and conformity to aims in the sphere of nature must be themselves explained

upon natural grounds and according to natural laws; and the wildest hypotheses, if they are only physical, are

here more admissible than a hyperphysical hypothesis, such as that of a divine author. For such a hypothesis

would introduce the principle of ignava ratio, which requires us to give up the search for causes that might be

discovered in the course of experience and to rest satisfied with a mere idea. As regards the absolute totality

of the grounds of explanation in the series of these causes, this can be no hindrance to the understanding in

the case of phenomena; because, as they are to us nothing more than phenomena, we have no right to look for

Transcendental hypotheses are therefore inadmissible; and we cannot use the liberty of employing, in the

absence of physical, hyperphysical grounds of explanation. And this for two reasons; first, because such

hypothesis do not advance reason, but rather stop it in its progress; secondly, because this licence would

render fruitless all its exertions in its own proper sphere, which is that of experience. For, when the

explanation of natural phenomena happens to be difficult, we have constantly at hand a transcendental ground

of explanation, which lifts us above the necessity of investigating nature; and our inquiries are brought to a

close, not because we have obtained all the requisite knowledge, but because we abut upon a principle which

is incomprehensible and which, indeed, is so far back in the track of thought as to contain the conception of

The next requisite for the admissibility of a hypothesis is its sufficiency. That is, it must determine a priori

the consequences which are given in experience and which are supposed to follow from the hypothesis itself.

If we require to employ auxiliary hypotheses, the suspicion naturally arises that they are mere fictions;

because the necessity for each of them requires the same justification as in the case of the original hypothesis,

and thus their testimony is invalid. If we suppose the existence of an infinitely perfect cause, we possess

sufficient grounds for the explanation of the conformity to aims, the order and the greatness which we

observe in the universe; but we find ourselves obliged, when we observe the evil in the world and the

exceptions to these laws, to employ new hypothesis in support of the original one. We employ the idea of the

simple nature of the human soul as the foundation of all the theories we may form of its phenomena; but

when we meet with difficulties in our way, when we observe in the soul phenomena similar to the changes

which take place in matter, we require to call in new auxiliary hypotheses. These may, indeed, not be false,

but we do not know them to be true, because the only witness to their certitude is the hypothesis which they

We are not discussing the abovementioned assertions regarding the immaterial unity of the soul and the

existence of a Supreme Being as dogmata, which certain philosophers profess to demonstrate a priori, but

purely as hypotheses. In the former case, the dogmatist must take care that his arguments possess the

apodeictic certainty of a demonstration. For the assertion that the reality of such ideas is probable is as absurd

as a proof of the probability of a proposition in geometry. Pure abstract reason, apart from all experience, can

either cognize nothing at all; and hence the judgements it enounces are never mere opinions, they are either

apodeictic certainties, or declarations that nothing can be known on the subject. Opinions and probable

judgements on the nature of things can only be employed to explain given phenomena, or they may relate to

the effect, in accordance with empirical laws, of an actually existing cause. In other words, we must restrict

the sphere of opinion to the world of experience and nature. Beyond this region opinion is mere invention;

unless we are groping about for the truth on a path not yet fully known, and have some hopes of stumbling

But, although hypotheses are inadmissible in answers to the questions of pure speculative reason, they may

be employed in the defence of these answers. That is to say, hypotheses are admissible in polemic, but not in

the sphere of dogmatism. By the defence of statements of this character, I do not mean an attempt at

discovering new grounds for their support, but merely the refutation of the arguments of opponents. All a

priori synthetical propositions possess the peculiarity that, although the philosopher who maintains the reality

of the ideas contained in the proposition is not in possession of sufficient knowledge to establish the certainty

of his statements, his opponent is as little able to prove the truth of the opposite. This equality of fortune does

not allow the one party to be superior to the other in the sphere of speculative cognition; and it is this sphere,

accordingly, that is the proper arena of these endless speculative conflicts. But we shall afterwards show that,

in relation to its practical exercise, Reason has the right of admitting what, in the field of pure speculation,

she would not be justified in supposing, except upon perfectly sufficient grounds; because all such

suppositions destroy the necessary completeness of speculation a condition which the practical reason,

however, does not consider to be requisite. In this sphere, therefore, Reason is mistress of a possession, her

title to which she does not require to prove which, in fact, she could not do. The burden of proof

accordingly rests upon the opponent. But as he has just as little knowledge regarding the subject discussed,

and is as little able to prove the nonexistence of the object of an idea, as the philosopher on the other side is

to demonstrate its reality, it is evident that there is an advantage on the side of the philosopher who maintains

his proposition as a practically necessary supposition (melior est conditio possidentis). For he is at liberty to

employ, in selfdefence, the same weapons as his opponent makes use of in attacking him; that is, he has a

right to use hypotheses not for the purpose of supporting the arguments in favour of his own propositions, but

to show that his opponent knows no more than himself regarding the subject under 'discussion and cannot

Hypotheses are, therefore, admissible in the sphere of pure reason only as weapons for selfdefence, and not

as supports to dogmatical assertions. But the opposing party we must always seek for in ourselves. For

speculative reason is, in the sphere of transcendentalism, dialectical in its own nature. The difficulties and

objections we have to fear lie in ourselves. They are like old but never superannuated claims; and we must

seek them out, and settle them once and for ever, if we are to expect a permanent peace. External tranquility

is hollow and unreal. The root of these contradictions, which lies in the nature of human reason, must be

destroyed; and this can only be done by giving it, in the first instance, freedom to grow, nay, by nourishing it,

that it may send out shoots, and thus betray its own existence. It is our duty, therefore, to try to discover new

objections, to put weapons in the bands of our opponent, and to grant him the most favourable position in the

arena that he can wish. We have nothing to fear from these concessions; on the contrary, we may rather hope

that we shall thus make ourselves master of a possession which no one will ever venture to dispute.

The thinker requires, to be fully equipped, the hypotheses of pure reason, which, although but leaden

weapons (for they have not been steeled in the armoury of experience), are as useful as any that can be

employed by his opponents. If, accordingly, we have assumed, from a nonspeculative point of view, the

immaterial nature of the soul, and are met by the objection that experience seems to prove that the growth and

decay of our mental faculties are mere modifications of the sensuous organism we can weaken the force of

this objection by the assumption that the body is nothing but the fundamental phenomenon, to which, as a

necessary condition, all sensibility, and consequently all thought, relates in the present state of our existence;

and that the separation of soul and body forms the conclusion of the sensuous exercise of our power of

cognition and the beginning of the intellectual. The body would, in this view of the question, be regarded, not

as the cause of thought, but merely as its restrictive condition, as promotive of the sensuous and animal, but

as a hindrance to the pure and spiritual life; and the dependence of the animal life on the constitution of the

body, would not prove that the whole life of man was also dependent on the state of the organism. We might

go still farther, and discover new objections, or carry out to their extreme consequences those which have

Generation, in the human race as well as among the irrational animals, depends on so many accidents of

occasion, of proper sustenance, of the laws enacted by the government of a country of vice even, that it is

difficult to believe in the eternal existence of a being whose life has begun under circumstances so mean and

trivial, and so entirely dependent upon our own control. As regards the continuance of the existence of the

whole race, we need have no difficulties, for accident in single cases is subject to general laws; but, in the

case of each individual, it would seem as if we could hardly expect so wonderful an effect from causes so

insignificant. But, in answer to these objections, we may adduce the transcendental hypothesis that all life is

properly intelligible, and not subject to changes of time, and that it neither began in birth, nor will end in

death. We may assume that this life is nothing more than a sensuous representation of pure spiritual life; that

the whole world of sense is but an image, hovering before the faculty of cognition which we exercise in this

sphere, and with no more objective reality than a dream; and that if we could intuite ourselves and other

things as they really are, we should see ourselves in a world of spiritual natures, our connection with which

did not begin at our birth and will not cease with the destruction of the body. And so on.

We cannot be said to know what has been above asserted, nor do we seriously maintain the truth of these

assertions; and the notions therein indicated are not even ideas of reason, they are purely fictitious

conceptions. But this hypothetical procedure is in perfect conformity with the laws of reason. Our opponent

mistakes the absence of empirical conditions for a proof of the complete impossibility of all that we have

asserted; and we have to show him that be has not exhausted the whole sphere of possibility and that he can

as little compass that sphere by the laws of experience and nature, as we can lay a secure foundation for the

operations of reason beyond the region of experience. Such hypothetical defences against the pretensions of

an opponent must not be regarded as declarations of opinion. The philosopher abandons them, so soon as the

opposite party renounces its dogmatical conceit. To maintain a simply negative position in relation to

propositions which rest on an insecure foundation, well befits the moderation of a true philosopher; but to

uphold the objections urged against an opponent as proofs of the opposite statement is a proceeding just as

unwarrantable and arrogant as it is to attack the position of a philosopher who advances affirmative

It is evident, therefore, that hypotheses, in the speculative sphere, are valid, not as independent propositions,

but only relatively to opposite transcendent assumptions. For, to make the principles of possible experience

conditions of the possibility of things in general is just as transcendent a procedure as to maintain the

objective reality of ideas which can be applied to no objects except such as lie without the limits of possible

experience. The judgements enounced by pure reason must be necessary, or they must not be enounced at all.

Reason cannot trouble herself with opinions. But the hypotheses we have been discussing are merely

problematical judgements, which can neither be confuted nor proved; while, therefore, they are not personal

opinions, they are indispensable as answers to objections which are liable to be raised. But we must take care

to confine them to this function, and guard against any assumption on their part of absolute validity, a

proceeding which would involve reason in inextricable difficulties and contradictions.

It is a peculiarity, which distinguishes the proofs of transcendental synthetical propositions from those of all

other a priori synthetical cognitions, that reason, in the case of the former, does not apply its conceptions

directly to an object, but is first obliged to prove, a priori, the objective validity of these conceptions and the

possibility of their syntheses. This is not merely a prudential rule, it is essential to the very possibility of the

proof of a transcendental proposition. If I am required to pass, a priori, beyond the conception of an object, I

find that it is utterly impossible without the guidance of something which is not contained in the conception.

In mathematics, it is a priori intuition that guides my synthesis; and, in this case, all our conclusions may be

drawn immediately from pure intuition. In transcendental cognition, so long as we are dealing only with

conceptions of the understanding, we are guided by possible experience. That is to say, a proof in the sphere

of transcendental cognition does not show that the given conception (that of an event, for example) leads

directly to another conception (that of a cause) for this would be a saltus which nothing can justify; but it

shows that experience itself, and consequently the object of experience, is impossible without the connection

indicated by these conceptions. It follows that such a proof must demonstrate the possibility of arriving,

synthetically and a priori, at a certain knowledge of things, which was not contained in our conceptions of

these things. Unless we pay particular attention to this requirement, our proofs, instead of pursuing the

straight path indicated by reason, follow the tortuous road of mere subjective association. The illusory

conviction, which rests upon subjective causes of association, and which is considered as resulting from the

perception of a real and objective natural affinity, is always open to doubt and suspicion. For this reason, all

the attempts which have been made to prove the principle of sufficient reason, have, according to the

universal admission of philosophers, been quite unsuccessful; and, before the appearance of transcendental

criticism, it was considered better, as this principle could not be abandoned, to appeal boldly to the common

sense of mankind (a proceeding which always proves that the problem, which reason ought to solve, is one in

which philosophers find great difficulties), rather than attempt to discover new dogmatical proofs.

But, if the proposition to be proved is a proposition of pure reason, and if I aim at passing beyond my

empirical conceptions by the aid of mere ideas, it is necessary that the proof should first show that such a step

in synthesis is possible (which it is not), before it proceeds to prove the truth of the proposition itself. The

socalled proof of the simple nature of the soul from the unity of apperception, is a very plausible one. But it

contains no answer to the objection, that, as the notion of absolute simplicity is not a conception which is

directly applicable to a perception, but is an idea which must be inferred if at all from observation, it is by

no means evident how the mere fact of consciousness, which is contained in all thought, although in so far a

simple representation, can conduct me to the consciousness and cognition of a thing which is purely a

thinking substance. When I represent to my mind the power of my body as in motion, my body in this

thought is so far absolute unity, and my representation of it is a simple one; and hence I can indicate this

representation by the motion of a point, because I have made abstraction of the size or volume of the body.

But I cannot hence infer that, given merely the moving power of a body, the body may be cogitated as simple

substance, merely because the representation in my mind takes no account of its content in space, and is

consequently simple. The simple, in abstraction, is very different from the objectively simple; and hence the

Ego, which is simple in the first sense, may, in the second sense, as indicating the soul itself, be a very

complex conception, with a very various content. Thus it is evident that in all such arguments there lurks a

paralogism. We guess (for without some such surmise our suspicion would not be excited in reference to a

proof of this character) at the presence of the paralogism, by keeping ever before us a criterion of the

possibility of those synthetical propositions which aim at proving more than experience can teach us. This

criterion is obtained from the observation that such proofs do not lead us directly from the subject of the

proposition to be proved to the required predicate, but find it necessary to presuppose the possibility of

extending our cognition a priori by means of ideas. We must, accordingly, always use the greatest caution;

we require, before attempting any proof, to consider how it is possible to extend the sphere of cognition by

the operations of pure reason, and from what source we are to derive knowledge, which is not obtained from

the analysis of conceptions, nor relates, by anticipation, to possible experience. We shall thus spare ourselves

much severe and fruitless labour, by not expecting from reason what is beyond its power, or rather by

subjecting it to discipline, and teaching it to moderate its vehement desires for the extension of the sphere of

The first rule for our guidance is, therefore, not to attempt a transcendental proof, before we have considered

from what source we are to derive the principles upon which the proof is to be based, and what right we have

to expect that our conclusions from these principles will be veracious. If they are principles of the

understanding, it is vain to expect that we should attain by their means to ideas of pure reason; for these

principles are valid only in regard to objects of possible experience. If they are principles of pure reason, our

labour is alike in vain. For the principles of reason, if employed as objective, are without exception dialectical

and possess no validity or truth, except as regulative principles of the systematic employment of reason in

experience. But when such delusive proof are presented to us, it is our duty to meet them with the non liquet

of a matured judgement; and, although we are unable to expose the particular sophism upon which the proof

is based, we have a right to demand a deduction of the principles employed in it; and, if these principles have

their origin in pure reason alone, such a deduction is absolutely impossible. And thus it is unnecessary that

we should trouble ourselves with the exposure and confutation of every sophistical illusion; we may, at once,

bring all dialectic, which is inexhaustible in the production of fallacies, before the bar of critical reason,

which tests the principles upon which all dialectical procedure is based. The second peculiarity of

transcendental proof is that a transcendental proposition cannot rest upon more than a single proof. If I am

drawing conclusions, not from conceptions, but from intuition corresponding to a conception, be it pure

intuition, as in mathematics, or empirical, as in natural science, the intuition which forms the basis of my

inferences presents me with materials for many synthetical propositions, which I can connect in various

modes, while, as it is allowable to proceed from different points in the intention, I can arrive by different

But every transcendental proposition sets out from a conception, and posits the synthetical condition of the

possibility of an object according to this conception. There must, therefore, be but one ground of proof,

because it is the conception alone which determines the object; and thus the proof cannot contain anything

more than the determination of the object according to the conception. In our Transcendental Analytic, for

example, we inferred the principle: Every event has a cause, from the only condition of the objective

possibility of our conception of an event. This is that an event cannot be determined in time, and

consequently cannot form a part of experience, unless it stands under this dynamical law. This is the only

possible ground of proof; for our conception of an event possesses objective validity, that is, is a true

conception, only because the law of causality determines an object to which it can refer. Other arguments in

support of this principle have been attempted such as that from the contingent nature of a phenomenon; but

when this argument is considered, we can discover no criterion of contingency, except the fact of an event

of something happening, that is to say, the existence which is preceded by the nonexistence of an object,

and thus we fall back on the very thing to be proved. If the proposition: "Every thinking being is simple," is

to be proved, we keep to the conception of the ego, which is simple, and to which all thought has a relation.

The same is the case with the transcendental proof of the existence of a Deity, which is based solely upon the

harmony and reciprocal fitness of the conceptions of an ens realissimum and a necessary being, and cannot be

This caution serves to simplify very much the criticism of all propositions of reason. When reason employs

conceptions alone, only one proof of its thesis is possible, if any. When, therefore, the dogmatist advances

with ten arguments in favour of a proposition, we may be sure that not one of them is conclusive. For if he

possessed one which proved the proposition he brings forward to demonstration as must always be the case

with the propositions of pure reason what need is there for any more? His intention can only be similar to

that of the advocate who had different arguments for different judges; this availing himself of the weakness of

those who examine his arguments, who, without going into any profound investigation, adopt the view of the

The third rule for the guidance of pure reason in the conduct of a proof is that all transcendental proofs must

never be apagogic or indirect, but always ostensive or direct. The direct or ostensive proof not only

establishes the truth of the proposition to be proved, but exposes the grounds of its truth; the apagogic, on the

other hand, may assure us of the truth of the proposition, but it cannot enable us to comprehend the grounds

of its possibility. The latter is, accordingly, rather an auxiliary to an argument, than a strictly philosophical

and rational mode of procedure. In one respect, however, they have an advantage over direct proofs, from the

fact that the mode of arguing by contradiction, which they employ, renders our understanding of the question

more clear, and approximates the proof to the certainty of an intuitional demonstration.

The true reason why indirect proofs are employed in different sciences is this. When the grounds upon which

we seek to base a cognition are too various or too profound, we try whether or not we may not discover the

truth of our cognition from its consequences. The modus ponens of reasoning from the truth of its inferences

to the truth of a proposition would be admissible if all the inferences that can be drawn from it are known to

be true; for in this case there can be only one possible ground for these inferences, and that is the true one.

But this is a quite impracticable procedure, as it surpasses all our powers to discover all the possible

inferences that can be drawn from a proposition. But this mode of reasoning is employed, under favour, when

we wish to prove the truth of an hypothesis; in which case we admit the truth of the conclusion which is

supported by analogy that, if all the inferences we have drawn and examined agree with the proposition

assumed, all other possible inferences will also agree with it. But, in this way, an hypothesis can never be

established as a demonstrated truth. The modus tollens of reasoning from known inferences to the unknown

proposition, is not only a rigorous, but a very easy mode of proof. For, if it can be shown that but one

inference from a proposition is false, then the proposition must itself be false. Instead, then, of examining, in

an ostensive argument, the whole series of the grounds on which the truth of a proposition rests, we need only

take the opposite of this proposition, and if one inference from it be false, then must the opposite be itself

false; and, consequently, the proposition which we wished to prove must be true.

The apagogic method of proof is admissible only in those sciences where it is impossible to mistake a

subjective representation for an objective cognition. Where this is possible, it is plain that the opposite of a

given proposition may contradict merely the subjective conditions of thought, and not the objective

cognition; or it may happen that both propositions contradict each other only under a subjective condition,

which is incorrectly considered to be objective, and, as the condition is itself false, both propositions may be

false, and it will, consequently, be impossible to conclude the truth of the one from the falseness of the other.

In mathematics such subreptions are impossible; and it is in this science, accordingly, that the indirect mode

of proof has its true place. In the science of nature, where all assertion is based upon empirical intuition, such

subreptions may be guarded against by the repeated comparison of observations; but this mode of proof is of

little value in this sphere of knowledge. But the transcendental efforts of pure reason are all made in the

sphere of the subjective, which is the real medium of all dialectical illusion; and thus reason endeavours, in

its premisses, to impose upon us subjective representations for objective cognitions. In the transcendental

sphere of pure reason, then, and in the case of synthetical propositions, it is inadmissible to support a

statement by disproving the counterstatement. For only two cases are possible; either, the counterstatement

is nothing but the enouncement of the inconsistency of the opposite opinion with the subjective conditions of

reason, which does not affect the real case (for example, we cannot comprehend the unconditioned necessity

of the existence of a being, and hence every speculative proof of the existence of such a being must be

opposed on subjective grounds, while the possibility of this being in itself cannot with justice be denied); or,

both propositions, being dialectical in their nature, are based upon an impossible conception. In this latter

case the rule applies: non entis nulla sunt predicata; that is to say, what we affirm and what we deny,

respecting such an object, are equally untrue, and the apagogic mode of arriving at the truth is in this case

impossible. If, for example, we presuppose that the world of sense is given in itself in its totality, it is false,

either that it is infinite, or that it is finite and limited in space. Both are false, because the hypothesis is false.

For the notion of phenomena (as mere representations) which are given in themselves (as objects) is

selfcontradictory; and the infinitude of this imaginary whole would, indeed, be unconditioned, but would be

inconsistent (as everything in the phenomenal world is conditioned) with the unconditioned determination

The apagogic mode of proof is the true source of those illusions which have always had so strong an

attraction for the admirers of dogmatical philosophy. It may be compared to a champion who maintains the

honour and claims of the party he has adopted by offering battle to all who doubt the validity of these claims

and the purity of that honour; while nothing can be proved in this way, except the respective strength of the

combatants, and the advantage, in this respect, is always on the side of the attacking party. Spectators,

observing that each party is alternately conqueror and conquered, are led to regard the subject of dispute as

beyond the power of man to decide upon. But such an opinion cannot be justified; and it is sufficient to apply

Each must try to establish his assertions by a transcendental deduction of the grounds of proof employed in

his argument, and thus enable us to see in what way the claims of reason may be supported. If an opponent

bases his assertions upon subjective grounds, he may be refuted with ease; not, however to the advantage of

the dogmatist, who likewise depends upon subjective sources of cognition and is in like manner driven into a

corner by his opponent. But, if parties employ the direct method of procedure, they will soon discover the

difficulty, nay, the impossibility of proving their assertions, and will be forced to appeal to prescription and

precedence; or they will, by the help of criticism, discover with ease the dogmatical illusions by which they

had been mocked, and compel reason to renounce its exaggerated pretensions to speculative insight and to

confine itself within the limits of its proper sphere that of practical principles.

It is a humiliating consideration for human reason that it is incompetent to discover truth by means of pure

speculation, but, on the contrary, stands in need of discipline to check its deviations from the straight path

and to expose the illusions which it originates. But, on the other hand, this consideration ought to elevate and

to give it confidence, for this discipline is exercised by itself alone, and it is subject to the censure of no other

power. The bounds, moreover, which it is forced to set to its speculative exercise, form likewise a check upon

the fallacious pretensions of opponents; and thus what remains of its possessions, after these exaggerated

claims have been disallowed, is secure from attack or usurpation. The greatest, and perhaps the only, use of

all philosophy of pure reason is, accordingly, of a purely negative character. It is not an organon for the

extension, but a discipline for the determination, of the limits of its exercise; and without laying claim to the

At the same time, there must be some source of positive cognitions which belong to the domain of pure

reason and which become the causes of error only from our mistaking their true character, while they form

the goal towards which reason continually strives. How else can we account for the inextinguishable desire in

the human mind to find a firm footing in some region beyond the limits of the world of experience? It hopes

to attain to the possession of a knowledge in which it has the deepest interest. It enters upon the path of pure

speculation; but in vain. We have some reason, however, to expect that, in the only other way that lies open

I understand by a canon a list of the a priori principles of the proper employment of certain faculties of

cognition. Thus general logic, in its analytical department, is a formal canon for the faculties of understanding

and reason. In the same way, Transcendental Analytic was seen to be a canon of the pure understanding; for it

alone is competent to enounce true a priori synthetical cognitions. But, when no proper employment of a

faculty of cognition is possible, no canon can exist. But the synthetical cognition of pure speculative reason

is, as has been shown, completely impossible. There cannot, therefore, exist any canon for the speculative

exercise of this faculty for its speculative exercise is entirely dialectical; and, consequently, transcendental

logic, in this respect, is merely a discipline, and not a canon. If, then, there is any proper mode of employing

the faculty of pure reason in which case there must be a canon for this faculty this canon will relate, not to

the speculative, but to the practical use of reason. This canon we now proceed to investigate.

There exists in the faculty of reason a natural desire to venture beyond the field of experience, to attempt to

reach the utmost bounds of all cognition by the help of ideas alone, and not to rest satisfied until it has

fulfilled its course and raised the sum of its cognitions into a selfsubsistent systematic whole. Is the motive

for this endeavour to be found in its speculative, or in its practical interests alone?

Setting aside, at present, the results of the labours of pure reason in its speculative exercise, I shall merely

inquire regarding the problems the solution of which forms its ultimate aim, whether reached or not, and in

relation to which all other aims are but partial and intermediate. These highest aims must, from the nature of

reason, possess complete unity; otherwise the highest interest of humanity could not be successfully

The transcendental speculation of reason relates to three things: the freedom of the will, the immortality of

the soul, and the existence of God. The speculative interest which reason has in those questions is very small;

and, for its sake alone, we should not undertake the labour of transcendental investigation a labour full of

toil and ceaseless struggle. We should be loth to undertake this labour, because the discoveries we might

make would not be of the smallest use in the sphere of concrete or physical investigation. We may find out

that the will is free, but this knowledge only relates to the intelligible cause of our volition. As regards the

phenomena or expressions of this will, that is, our actions, we are bound, in obedience to an inviolable

maxim, without which reason cannot be employed in the sphere of experience, to explain these in the same

way as we explain all the other phenomena of nature, that is to say, according to its unchangeable laws. We

may have discovered the spirituality and immortality of the soul, but we cannot employ this knowledge to

explain the phenomena of this life, nor the peculiar nature of the future, because our conception of an

incorporeal nature is purely negative and does not add anything to our knowledge, and the only inferences to

be drawn from it are purely fictitious. If, again, we prove the existence of a supreme intelligence, we should

be able from it to make the conformity to aims existing in the arrangement of the world comprehensible; but

we should not be justified in deducing from it any particular arrangement or disposition, or inferring any

where it is not perceived. For it is a necessary rule of the speculative use of reason that we must not overlook

natural causes, or refuse to listen to the teaching of experience, for the sake of deducing what we know and

perceive from something that transcends all our knowledge. In one word, these three propositions are, for the

speculative reason, always transcendent, and cannot be employed as immanent principles in relation to the

objects of experience; they are, consequently, of no use to us in this sphere, being but the valueless results of

If, then, the actual cognition of these three cardinal propositions is perfectly useless, while Reason uses her

utmost endeavours to induce us to admit them, it is plain that their real value and importance relate to our

I term all that is possible through free will, practical. But if the conditions of the exercise of free volition are

empirical, reason can have only a regulative, and not a constitutive, influence upon it, and is serviceable

merely for the introduction of unity into its empirical laws. In the moral philosophy of prudence, for example,

the sole business of reason is to bring about a union of all the ends, which are aimed at by our inclinations,

into one ultimate end that of happiness and to show the agreement which should exist among the means of

attaining that end. In this sphere, accordingly, reason cannot present to us any other than pragmatical laws of

free action, for our guidance towards the aims set up by the senses, and is incompetent to give us laws which

are pure and determined completely a priori. On the other hand, pure practical laws, the ends of which have

been given by reason entirely a priori, and which are not empirically conditioned, but are, on the contrary,

absolutely imperative in their nature, would be products of pure reason. Such are the moral laws; and these

alone belong to the sphere of the practical exercise of reason, and admit of a canon.

All the powers of reason, in the sphere of what may be termed pure philosophy, are, in fact, directed to the

three abovementioned problems alone. These again have a still higher end the answer to the question, what

we ought to do, if the will is free, if there is a God and a future world. Now, as this problem relates to our in

reference to the highest aim of humanity, it is evident that the ultimate intention of nature, in the constitution

We must take care, however, in turning our attention to an object which is foreign* to the sphere of

transcendental philosophy, not to injure the unity of our system by digressions, nor, on the other hand, to fail

in clearness, by saying too little on the new subject of discussion. I hope to avoid both extremes, by keeping

as close as possible to the transcendental, and excluding all psychological, that is, empirical, elements.

*All practical conceptions relate to objects of pleasure and pain, and consequently in an indirect manner, at

least to objects of feeling. But as feeling is not a faculty of representation, but lies out of the sphere of our

powers of cognition, the elements of our judgements, in so far as they relate to pleasure or pain, that is, the

elements of our practical judgements, do not belong to transcendental philosophy, which has to do with pure

I have to remark, in the first place, that at present I treat of the conception of freedom in the practical sense

only, and set aside the corresponding transcendental conception, which cannot be employed as a ground of

explanation in the phenomenal world, but is itself a problem for pure reason. A will is purely animal

(arbitrium brutum) when it is determined by sensuous impulses or instincts only, that is, when it is

determined in a pathological manner. A will, which can be determined independently of sensuous impulses,

consequently by motives presented by reason alone, is called a free will (arbitrium liberum); and everything

which is connected with this free will, either as principle or consequence, is termed practical. The existence

of practical freedom can be proved from experience alone. For the human will is not determined by that alone

which immediately affects the senses; on the contrary, we have the power, by calling up the notion of what is

useful or hurtful in a more distant relation, of overcoming the immediate impressions on our sensuous faculty

of desire. But these considerations of what is desirable in relation to our whole state, that is, is in the end

good and useful, are based entirely upon reason. This faculty, accordingly, enounces laws, which are

imperative or objective laws of freedom and which tell us what ought to take place, thus distinguishing

themselves from the laws of nature, which relate to that which does take place. The laws of freedom or of

Whether reason is not itself, in the actual delivery of these laws, determined in its turn by other influences,

and whether the action which, in relation to sensuous impulses, we call free, may not, in relation to higher

and more remote operative causes, really form a part of nature these are questions which do not here

concern us. They are purely speculative questions; and all we have to do, in the practical sphere, is to inquire

into the rule of conduct which reason has to present. Experience demonstrates to us the existence of practical

freedom as one of the causes which exist in nature, that is, it shows the causal power of reason in the

determination of the will. The idea of transcendental freedom, on the contrary, requires that reason in

relation to its causal power of commencing a series of phenomena should be independent of all sensuous

determining causes; and thus it seems to be in opposition to the law of nature and to all possible experience.

It therefore remains a problem for the human mind. But this problem does not concern reason in its practical

use; and we have, therefore, in a canon of pure reason, to do with only two questions, which relate to the

practical interest of pure reason: Is there a God? and, Is there a future life? The question of transcendental

freedom is purely speculative, and we may therefore set it entirely aside when we come to treat of practical

reason. Besides, we have already discussed this subject in the antinomy of pure reason.

Reason conducted us, in its speculative use, through the field of experience and, as it can never find complete

satisfaction in that sphere, from thence to speculative ideas which, however, in the end brought us back

again to experience, and thus fulfilled the purpose of reason, in a manner which, though useful, was not at all

in accordance with our expectations. It now remains for us to consider whether pure reason can be employed

in a practical sphere, and whether it will here conduct us to those ideas which attain the highest ends of pure

reason, as we have just stated them. We shall thus ascertain whether, from the point of view of its practical

interest, reason may not be able to supply us with that which, on the speculative side, it wholly denies us.

The whole interest of reason, speculative as well as practical, is centred in the three following questions:

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The first question is purely speculative. We have, as I flatter myself, exhausted all the replies of which it is

susceptible, and have at last found the reply with which reason must content itself, and with which it ought to

be content, so long as it pays no regard to the practical. But from the two great ends to the attainment of

which all these efforts of pure reason were in fact directed, we remain just as far removed as if we had

consulted our ease and declined the task at the outset. So far, then, as knowledge is concerned, thus much, at

least, is established, that, in regard to those two problems, it lies beyond our reach.

The second question is purely practical. As such it may indeed fall within the province of pure reason, but

still it is not transcendental, but moral, and consequently cannot in itself form the subject of our criticism.

The third question: If I act as I ought to do, what may I then hope? is at once practical and theoretical. The

practical forms a clue to the answer of the theoretical, and in its highest form speculative question. For all

hoping has happiness for its object and stands in precisely the same relation to the practical and the law of

morality as knowing to the theoretical cognition of things and the law of nature. The former arrives finally at

the conclusion that something is (which determines the ultimate end), because something ought to take place;

the latter, that something is (which operates as the highest cause), because something does take place.

Happiness is the satisfaction of all our desires; extensive, in regard to their multiplicity; intensive, in regard to

their degree; and protensive, in regard to their duration. The practical law based on the motive of happiness I

term a pragmatical law (or prudential rule); but that law, assuming such to exist, which has no other motive

than the worthiness of being happy, I term a moral or ethical law. The first tells us what we have to do, if we

wish to become possessed of happiness; the second dictates how we ought to act, in order to deserve

happiness. The first is based upon empirical principles; for it is only by experience that I can learn either what

inclinations exist which desire satisfaction, or what are the natural means of satisfying them. The second

takes no account of our desires or the means of satisfying them, and regards only the freedom of a rational

being, and the necessary conditions under which alone this freedom can harmonize with the distribution of

happiness according to principles. This second law may therefore rest upon mere ideas of pure reason, and

I assume that there are pure moral laws which determine, entirely a priori (without regard to empirical

motives, that is, to happiness), the conduct of a rational being, or in other words, to use which it makes of its

freedom, and that these laws are absolutely imperative (not merely hypothetically, on the supposition of other

empirical ends), and therefore in all respects necessary. I am warranted in assuming this, not only by the

arguments of the most enlightened moralists, but by the moral judgement of every man who will make the

Pure reason, then, contains, not indeed in its speculative, but in its practical, or, more strictly, its moral use,

principles of the possibility of experience, of such actions, namely, as, in accordance with ethical precepts,

might be met with in the history of man. For since reason commands that such actions should take place, it

must be possible for them to take place; and hence a particular kind of systematic unity the moral must be

possible. We have found, it is true, that the systematic unity of nature could not be established according to

speculative principles of reason, because, while reason possesses a causal power in relation to freedom, it has

none in relation to the whole sphere of nature; and, while moral principles of reason can produce free actions,

they cannot produce natural laws. It is, then, in its practical, but especially in its moral use, that the principles

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I call the world a moral world, in so far as it may be in accordance with all the ethical laws which, by virtue

of the freedom of reasonable beings, it can be, and according to the necessary laws of morality it ought to be.

But this world must be conceived only as an intelligible world, inasmuch as abstraction is therein made of all

conditions (ends), and even of all impediments to morality (the weakness or pravity of human nature). So far,

then, it is a mere idea though still a practical idea which may have, and ought to have, an influence on the

world of sense, so as to bring it as far as possible into conformity with itself. The idea of a moral world has,

therefore, objective reality, not as referring to an object of intelligible intuition for of such an object we can

form no conception whatever but to the world of sense conceived, however, as an object of pure reason in

its practical use and to a corpus mysticum of rational beings in it, in so far as the liberum arbitrium of the

individual is placed, under and by virtue of moral laws, in complete systematic unity both with itself and with

That is the answer to the first of the two questions of pure reason which relate to its practical interest: Do that

which will render thee worthy of happiness. The second question is this: If I conduct myself so as not to be

unworthy of happiness, may I hope thereby to obtain happiness? In order to arrive at the solution of this

question, we must inquire whether the principles of pure reason, which prescribe a priori the law, necessarily

I say, then, that just as the moral principles are necessary according to reason in its practical use, so it is

equally necessary according to reason in its theoretical use to assume that every one has ground to hope for

happiness in the measure in which he has made himself worthy of it in his conduct, and that therefore the

system of morality is inseparably (though only in the idea of pure reason) connected with that of happiness.

Now in an intelligible, that is, in the moral world, in the conception of which we make abstraction of all the

impediments to morality (sensuous desires), such a system of happiness, connected with and proportioned to

morality, may be conceived as necessary, because freedom of volition partly incited, and partly restrained

by moral laws would be itself the cause of general happiness; and thus rational beings, under the guidance

of such principles, would be themselves the authors both of their own enduring welfare and that of others.

But such a system of selfrewarding morality is only an idea, the carrying out of which depends upon the

condition that every one acts as he ought; in other words, that all actions of reasonable beings be such as they

would be if they sprung from a Supreme Will, comprehending in, or under, itself all particular wills. But

since the moral law is binding on each individual in the use of his freedom of volition, even if others should

not act in conformity with this law, neither the nature of things, nor the causality of actions and their relation

to morality, determine how the consequences of these actions will be related to happiness; and the necessary

connection of the hope of happiness with the unceasing endeavour to become worthy of happiness, cannot be

cognized by reason, if we take nature alone for our guide. This connection can be hoped for only on the

assumption that the cause of nature is a supreme reason, which governs according to moral laws.

I term the idea of an intelligence in which the morally most perfect will, united with supreme blessedness, is

the cause of all happiness in the world, so far as happiness stands in strict } relation to morality (as the

worthiness of being happy), the ideal of the supreme Good. supreme original good, that pure reason can find

the ground of the practically necessary connection of both elements of the highest derivative good, and

accordingly of an intelligible, that is, moral world. Now since we are necessitated by reason to conceive

ourselves as belonging to such a world, while the senses present to us nothing but a world of phenomena, we

must assume the former as a consequence of our conduct in the world of sense (since the world of sense gives

us no hint of it), and therefore as future in relation to us. Thus God and a future life are two hypotheses

which, according to the principles of pure reason, are inseparable from the obligation which this reason

Morality per se constitutes a system. But we can form no system of happiness, except in so far as it is

dispensed in strict proportion to morality. But this is only possible in the intelligible world, under a wise

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author and ruler. Such a ruler, together with life in such a world, which we must look upon as future, reason

finds itself compelled to assume; or it must regard the moral laws as idle dreams, since the necessary

consequence which this same reason connects with them must, without this hypothesis, fall to the ground.

Hence also the moral laws are universally regarded as commands, which they could not be did they not

connect a priori adequate consequences with their dictates, and thus carry with them promises and threats.

But this, again, they could not do, did they not reside in a necessary being, as the Supreme Good, which alone

Leibnitz termed the world, when viewed in relation to the rational beings which it contains, and the moral

relations in which they stand to each other, under the government of the Supreme Good, the kingdom of

Grace, and distinguished it from the kingdom of Nature, in which these rational beings live, under moral

laws, indeed, but expect no other consequences from their actions than such as follow according to the course

of nature in the world of sense. To view ourselves, therefore, as in the kingdom of grace, in which all

happiness awaits us, except in so far as we ourselves limit our participation in it by actions which render us

Practical laws, in so far as they are subjective grounds of actions, that is, subjective principles, are termed

maxims. The judgements of moral according to in its purity and ultimate results are framed according ideas;

The whole course of our life must be subject to moral maxims; but this is impossible, unless with the moral

law, which is a mere idea, reason connects an efficient cause which ordains to all conduct which is in

conformity with the moral law an issue either in this or in another life, which is in exact conformity with our

highest aims. Thus, without a God and without a world, invisible to us now, but hoped for, the glorious ideas

of morality are, indeed, objects of approbation and of admiration, but cannot be the springs of purpose and

action. For they do not satisfy all the aims which are natural to every rational being, and which are

Happiness alone is, in the view of reason, far from being the complete good. Reason does not approve of it

(however much inclination may desire it), except as united with desert. On the other hand, morality alone,

and with it, mere desert, is likewise far from being the complete good. To make it complete, he who conducts

himself in a manner not unworthy of happiness, must be able to hope for the possession of happiness. Even

reason, unbiased by private ends, or interested considerations, cannot judge otherwise, if it puts itself in the

place of a being whose business it is to dispense all happiness to others. For in the practical idea both points

are essentially combined, though in such a way that participation in happiness is rendered possible by the

moral disposition, as its condition, and not conversely, the moral disposition by the prospect of happiness.

For a disposition which should require the prospect of happiness as its necessary condition would not be

moral, and hence also would not be worthy of complete happiness a happiness which, in the view of reason,

Happiness, therefore, in exact proportion with the morality of rational beings (whereby they are made worthy

of happiness), constitutes alone the supreme good of a world into which we absolutely must transport

ourselves according to the commands of pure but practical reason. This world is, it is true, only an intelligible

world; for of such a systematic unity of ends as it requires, the world of sense gives us no hint. Its reality can

be based on nothing else but the hypothesis of a supreme original good. In it independent reason, equipped

with all the sufficiency of a supreme cause, founds, maintains, and fulfils the universal order of things, with

the most perfect teleological harmony, however much this order may be hidden from us in the world of sense.

This moral theology has the peculiar advantage, in contrast with speculative theology, of leading inevitably to

the conception of a sole, perfect, and rational First Cause, whereof speculative theology does not give us any

indication on objective grounds, far less any convincing evidence. For we find neither in transcendental nor

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in natural theology, however far reason may lead us in these, any ground to warrant us in assuming the

existence of one only Being, which stands at the head of all natural causes, and on which these are entirely

dependent. On the other band, if we take our stand on moral unity as a necessary law of the universe, and

from this point of view consider what is necessary to give this law adequate efficiency and, for us, obligatory

force, we must come to the conclusion that there is one only supreme will, which comprehends all these laws

in itself. For how, under different wills, should we find complete unity of ends? This will must be

omnipotent, that all nature and its relation to morality in the world may be subject to it; omniscient, that it

may have knowledge of the most secret feelings and their moral worth; omnipresent, that it may be at hand to

supply every necessity to which the highest weal of the world may give rise; eternal, that this harmony of

But this systematic unity of ends in this world of intelligences which, as mere nature, is only a world of

sense, but, as a system of freedom of volition, may be termed an intelligible, that is, moral world (regnum

gratiae) leads inevitably also to the teleological unity of all things which constitute this great whole,

according to universal natural laws just as the unity of the former is according to universal and necessary

moral laws and unites the practical with the speculative reason. The world must be represented as having

originated from an idea, if it is to harmonize with that use of reason without which we cannot even consider

ourselves as worthy of reason namely, the moral use, which rests entirely on the idea of the supreme good.

Hence the investigation of nature receives a teleological direction, and becomes, in its widest extension,

physicotheology. But this, taking its rise in moral order as a unity founded on the essence of freedom, and

not accidentally instituted by external commands, establishes the teleological view of nature on grounds

which must be inseparably connected with the internal possibility of things. This gives rise to a

transcendental theology, which takes the ideal of the highest ontological perfection as a principle of

systematic unity; and this principle connects all things according to universal and necessary natural laws,

because all things have their origin in the absolute necessity of the one only Primal Being.

What use can we make of our understanding, even in respect of experience, if we do not propose ends to

ourselves? But the highest ends are those of morality, and it is only pure reason that can give us the

knowledge of these. Though supplied with these, and putting ourselves under their guidance, we can make no

teleological use of the knowledge of nature, as regards cognition, unless nature itself has established

teleological unity. For without this unity we should not even possess reason, because we should have no

school for reason, and no cultivation through objects which afford the materials for its conceptions. But

teleological unity is a necessary unity, and founded on the essence of the individual will itself. Hence this

will, which is the condition of the application of this unity in concreto, must be so likewise. In this way the

transcendental enlargement of our rational cognition would be, not the cause, but merely the effect of the

Hence, also, we find in the history of human reason that, before the moral conceptions were sufficiently

purified and determined, and before men had attained to a perception of the systematic unity of ends

according to these conceptions and from necessary principles, the knowledge of nature, and even a

considerable amount of intellectual culture in many other sciences, could produce only rude and vague

conceptions of the Deity, sometimes even admitting of an astonishing indifference with regard to this

question altogether. But the more enlarged treatment of moral ideas, which was rendered necessary by the

extreme pure moral law of our religion, awakened the interest, and thereby quickened the perceptions of

reason in relation to this object. In this way, and without the help either of an extended acquaintance with

nature, or of a reliable transcendental insight (for these have been wanting in all ages), a conception of the

Divine Being was arrived at, which we now bold to be the correct one, not because speculative reason

convinces us of its correctness, but because it accords with the moral principles of reason. Thus it is to pure

reason, but only in its practical use, that we must ascribe the merit of having connected with our highest

interest a cognition, of which mere speculation was able only to form a conjecture, but the validity of which it

was unable to establish and of having thereby rendered it, not indeed a demonstrated dogma, but a

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But if practical reason has reached this elevation, and has attained to the conception of a sole Primal Being as

the supreme good, it must not, therefore, imagine that it has transcended the empirical conditions of its

application, and risen to the immediate cognition of new objects; it must not presume to start from the

conception which it has gained, and to deduce from it the moral laws themselves. For it was these very laws,

the internal practical necessity of which led us to the hypothesis of an independent cause, or of a wise ruler of

the universe, who should give them effect. Hence we are not entitled to regard them as accidental and derived

from the mere will of the ruler, especially as we have no conception of such a will, except as formed in

accordance with these laws. So far, then, as practical reason has the right to conduct us, we shall not look

upon actions as binding on us, because they are the commands of God, but we shall regard them as divine

commands, because we are internally bound by them. We shall study freedom under the teleological unity

which accords with principles of reason; we shall look upon ourselves as acting in conformity with the divine

will only in so far as we hold sacred the moral law which reason teaches us from the nature of actions

themselves, and we shall believe that we can obey that will only by promoting the weal of the universe in

ourselves and in others. Moral theology is, therefore, only of immanent use. It teaches us to fulfil our destiny

here in the world, by placing ourselves in harmony with the general system of ends, and warns us against the

fanaticism, nay, the crime of depriving reason of its legislative authority in the moral conduct of life, for the

purpose of directly connecting this authority with the idea of the Supreme Being. For this would be, not an

immanent, but a transcendent use of moral theology, and, like the transcendent use of mere speculation,

The holding of a thing to be true is a phenomenon in our understanding which may rest on objective grounds,

but requires, also, subjective causes in the mind of the person judging. If a judgement is valid for every

rational being, then its ground is objectively sufficient, and it is termed a conviction. If, on the other hand, it

has its ground in the particular character of the subject, it is termed a persuasion.

Persuasion is a mere illusion, the ground of the judgement, which lies solely in the subject, being regarded as

objective. Hence a judgement of this kind has only private validity is only valid for the individual who

judges, and the holding of a thing to be true in this way cannot be communicated. But truth depends upon

agreement with the object, and consequently the judgements of all understandings, if true, must be in

agreement with each other (consentientia uni tertio consentiunt inter se). Conviction may, therefore, be

distinguished, from an external point of view, from persuasion, by the possibility of communicating it and by

showing its validity for the reason of every man; for in this case the presumption, at least, arises that the

agreement of all judgements with each other, in spite of the different characters of individuals, rests upon the

common ground of the agreement of each with the object, and thus the correctness of the judgement is

Persuasion, accordingly, cannot be subjectively distinguished from conviction, that is, so long as the subject

views its judgement simply as a phenomenon of its own mind. But if we inquire whether the grounds of our

judgement, which are valid for us, produce the same effect on the reason of others as on our own, we have

then the means, though only subjective means, not, indeed, of producing conviction, but of detecting the

merely private validity of the judgement; in other words, of discovering that there is in it the element of mere

If we can, in addition to this, develop the subjective causes of the judgement, which we have taken for its

objective grounds, and thus explain the deceptive judgement as a phenomenon in our mind, apart altogether

from the objective character of the object, we can then expose the illusion and need be no longer deceived by

it, although, if its subjective cause lies in our nature, we cannot hope altogether to escape its influence.

I can only maintain, that is, affirm as necessarily valid for every one, that which produces conviction.

Persuasion I may keep for myself, if it is agreeable to me; but I cannot, and ought not, to attempt to impose it

Holding for true, or the subjective validity of a judgement in relation to conviction (which is, at the same

time, objectively valid), has the three following degrees: opinion, belief, and knowledge. Opinion is a

consciously insufficient judgement, subjectively as well as objectively. Belief is subjectively sufficient, but is

recognized as being objectively insufficient. Knowledge is both subjectively and objectively sufficient.

Subjective sufficiency is termed conviction (for myself); objective sufficiency is termed certainty (for all). I

I must never venture to be of opinion, without knowing something, at least, by which my judgement, in itself

merely problematical, is brought into connection with the truth which connection, although not perfect, is

still something more than an arbitrary fiction. Moreover, the law of such a connection must be certain. For if,

in relation to this law, I have nothing more than opinion, my judgement is but a play of the imagination,

without the least relation to truth. In the judgements of pure reason, opinion has no place. For, as they do not

rest on empirical grounds and as the sphere of pure reason is that of necessary truth and a priori cognition, the

principle of connection in it requires universality and necessity, and consequently perfect certainty

otherwise we should have no guide to the truth at all. Hence it is absurd to have an opinion in pure

mathematics; we must know, or abstain from forming a judgement altogether. The case is the same with the

maxims of morality. For we must not hazard an action on the mere opinion that it is allowed, but we must

In the transcendental sphere of reason, on the other hand, the term opinion is too weak, while the word

knowledge is too strong. From the merely speculative point of view, therefore, we cannot form a judgement

at all. For the subjective grounds of a judgement, such as produce belief, cannot be admitted in speculative

inquiries, inasmuch as they cannot stand without empirical support and are incapable of being communicated

But it is only from the practical point of view that a theoretically insufficient judgement can be termed belief.

Now the practical reference is either to skill or to morality; to the former, when the end proposed is arbitrary

If we propose to ourselves any end whatever, the conditions of its attainment are hypothetically necessary.

The necessity is subjectively, but still only comparatively, sufficient, if I am acquainted with no other

conditions under which the end can be attained. On the other hand, it is sufficient, absolutely and for every

one, if I know for certain that no one can be acquainted with any other conditions under which the attainment

of the proposed end would be possible. In the former case my supposition my judgement with regard to

certain conditions is a merely accidental belief; in the latter it is a necessary belief. The physician must

pursue some course in the case of a patient who is in danger, but is ignorant of the nature of the disease. He

observes the symptoms, and concludes, according to the best of his judgement, that it is a case of phthisis.

His belief is, even in his own judgement, only contingent: another man might, perhaps come nearer the truth.

Such a belief, contingent indeed, but still forming the ground of the actual use of means for the attainment of

The usual test, whether that which any one maintains is merely his persuasion, or his subjective conviction at

least, that is, his firm belief, is a bet. It frequently happens that a man delivers his opinions with so much

boldness and assurance, that he appears to be under no apprehension as to the possibility of his being in error.

The offer of a bet startles him, and makes him pause. Sometimes it turns out that his persuasion may be

valued at a ducat, but not at ten. For he does not hesitate, perhaps, to venture a ducat, but if it is proposed to

stake ten, he immediately becomes aware of the possibility of his being mistaken a possibility which has

hitherto escaped his observation. If we imagine to ourselves that we have to stake the happiness of our whole

life on the truth of any proposition, our judgement drops its air of triumph, we take the alarm, and discover

the actual strength of our belief. Thus pragmatical belief has degrees, varying in proportion to the interests at

Now, in cases where we cannot enter upon any course of action in reference to some object, and where,

accordingly, our judgement is purely theoretical, we can still represent to ourselves, in thought, the possibility

of a course of action, for which we suppose that we have sufficient grounds, if any means existed of

ascertaining the truth of the matter. Thus we find in purely theoretical judgements an analogon of practical

judgements, to which the word belief may properly be applied, and which we may term doctrinal belief. I

should not hesitate to stake my all on the truth of the proposition if there were any possibility of bringing it

to the test of experience that, at least, some one of the planets, which we see, is inhabited. Hence I say that I

have not merely the opinion, but the strong belief, on the correctness of which I would stake even many of

Now we must admit that the doctrine of the existence of God belongs to doctrinal belief. For, although in

respect to the theoretical cognition of the universe I do not require to form any theory which necessarily

involves this idea, as the condition of my explanation of the phenomena which the universe presents, but, on

the contrary, am rather bound so to use my reason as if everything were mere nature, still teleological unity is

so important a condition of the application of my reason to nature, that it is impossible for me to ignore it

especially since, in addition to these considerations, abundant examples of it are supplied by experience. But

the sole condition, so far as my knowledge extends, under which this unity can be my guide in the

investigation of nature, is the assumption that a supreme intelligence has ordered all things according to the

wisest ends. Consequently, the hypothesis of a wise author of the universe is necessary for my guidance in

the investigation of nature is the condition under which alone I can fulfil an end which is contingent indeed,

but by no means unimportant. Moreover, since the result of my attempts so frequently confirms the utility of

this assumption, and since nothing decisive can be adduced against it, it follows that it would be saying far

too little to term my judgement, in this case, a mere opinion, and that, even in this theoretical connection, I

may assert that I firmly believe in God. Still, if we use words strictly, this must not be called a practical, but a

doctrinal belief, which the theology of nature (physicotheology) must also produce in my mind. In the

wisdom of a Supreme Being, and in the shortness of life, so inadequate to the development of the glorious

powers of human nature, we may find equally sufficient grounds for a doctrinal belief in the future life of the

The expression of belief is, in such cases, an expression of modesty from the objective point of view, but, at

the same time, of firm confidence, from the subjective. If I should venture to term this merely theoretical

judgement even so much as a hypothesis which I am entitled to assume; a more complete conception, with

regard to another world and to the cause of the world, might then be justly required of me than I am, in

reality, able to give. For, if I assume anything, even as a mere hypothesis, I must, at least, know so much of

the properties of such a being as will enable me, not to form the conception, but to imagine the existence of it.

But the word belief refers only to the guidance which an idea gives me, and to its subjective influence on the

conduct of my reason, which forces me to hold it fast, though I may not be in a position to give a speculative

But mere doctrinal belief is, to some extent, wanting in stability. We often quit our hold of it, in consequence

of the difficulties which occur in speculation, though in the end we inevitably return to it again.

It is quite otherwise with moral belief. For in this sphere action is absolutely necessary, that is, I must act in

obedience to the moral law in all points. The end is here incontrovertibly established, and there is only one

condition possible, according to the best of my perception, under which this end can harmonize with all other

ends, and so have practical validity namely, the existence of a God and of a future world. I know also, to a

certainty, that no one can be acquainted with any other conditions which conduct to the same unity of ends

under the moral law. But since the moral precept is, at the same time, my maxim (as reason requires that it

should be), I am irresistibly constrained to believe in the existence of God and in a future life; and I am sure

that nothing can make me waver in this belief, since I should thereby overthrow my moral maxims, the

Thus, while all the ambitious attempts of reason to penetrate beyond the limits of experience end in

disappointment, there is still enough left to satisfy us in a practical point of view. No one, it is true, will be

able to boast that he knows that there is a God and a future life; for, if he knows this, be is just the man whom

I have long wished to find. All knowledge, regarding an object of mere reason, can be communicated; and I

should thus be enabled to hope that my own knowledge would receive this wonderful extension, through the

instrumentality of his instruction. No, my conviction is not logical, but moral certainty; and since it rests on

subjective grounds (of the moral sentiment), I must not even say: It is morally certain that there is a God, etc.,

but: I am morally certain, that is, my belief in God and in another world is so interwoven with my moral

nature that I am under as little apprehension of having the former torn from me as of losing the latter.

The only point in this argument that may appear open to suspicion is that this rational belief presupposes the

existence of moral sentiments. If we give up this assumption, and take a man who is entirely indifferent with

regard to moral laws, the question which reason proposes, becomes then merely a problem for speculation

and may, indeed, be supported by strong grounds from analogy, but not by such as will compel the most

obstinate scepticism to give way.* But in these questions no man is free from all interest. For though the want

of good sentiments may place him beyond the influence of moral interests, still even in this case enough may

be left to make him fear the existence of God and a future life. For he cannot pretend to any certainty of the

nonexistence of God and of a future life, unless since it could only be proved by mere reason, and

therefore apodeictically he is prepared to establish the impossibility of both, which certainly no reasonable

man would undertake to do. This would be a negative belief, which could not, indeed, produce morality and

good sentiments, but still could produce an analogon of these, by operating as a powerful restraint on the

*The human mind (as, I believe, every rational being must of necessity do) takes a natural interest in

morality, although this interest is not undivided, and may not be practically in preponderance. If you

strengthen and increase it, you will find the reason become docile, more enlightened, and more capable of

uniting the speculative interest with the practical. But if you do not take care at the outset, or at least midway,

But, it will be said, is this all that pure reason can effect, in opening up prospects beyond the limits of

experience? Nothing more than two articles of belief? Common sense could have done as much as this,

I shall not here eulogize philosophy for the benefits which the laborious efforts of its criticism have conferred

on human reason even granting that its merit should turn out in the end to be only negative for on this

point something more will be said in the next section. But, I ask, do you require that that knowledge which

concerns all men, should transcend the common understanding, and should only be revealed to you by

philosophers? The very circumstance which has called forth your censure, is the best confirmation of the

correctness of our previous assertions, since it discloses, what could not have been foreseen, that Nature is

not chargeable with any partial distribution of her gifts in those matters which concern all men without

distinction and that, in respect to the essential ends of human nature, we cannot advance further with the help

of the highest philosophy, than under the guidance which nature has vouchsafed to the meanest

By the term architectonic I mean the art of constructing a system. Without systematic unity, our knowledge

cannot become science; it will be an aggregate, and not a system. Thus architectonic is the doctrine of the

scientific in cognition, and therefore necessarily forms part of our methodology.

Reason cannot permit our knowledge to remain in an unconnected and rhapsodistic state, but requires that the

sum of our cognitions should constitute a system. It is thus alone that they can advance the ends of reason. By

a system I mean the unity of various cognitions under one idea. This idea is the conception given by reason

of the form of a whole, in so far as the conception determines a priori not only the limits of its content, but

the place which each of its parts is to occupy. The scientific idea contains, therefore, the end and the form of

the whole which is in accordance with that end. The unity of the end, to which all the parts of the system

relate, and through which all have a relation to each other, communicates unity to the whole system, so that

the absence of any part can be immediately detected from our knowledge of the rest; and it determines a

priori the limits of the system, thus excluding all contingent or arbitrary additions. The whole is thus an

organism (articulatio), and not an aggregate (coacervatio); it may grow from within (per intussusceptionem),

but it cannot increase by external additions (per appositionem). It is, thus, like an animal body, the growth of

which does not add any limb, but, without changing their proportions, makes each in its sphere stronger and

We require, for the execution of the idea of a system, a schema, that is, a content and an arrangement of parts

determined a priori by the principle which the aim of the system prescribes. A schema which is not projected

in accordance with an idea, that is, from the standpoint of the highest aim of reason, but merely empirically,

in accordance with accidental aims and purposes (the number of which cannot be predetermined), can give us

nothing more than technical unity. But the schema which is originated from an idea (in which case reason

presents us with aims a priori, and does not look for them to experience), forms the basis of architectonical

unity. A science, in the proper acceptation of that term. cannot be formed technically, that is, from

observation of the similarity existing between different objects, and the purely contingent use we make of our

knowledge in concreto with reference to all kinds of arbitrary external aims; its constitution must be framed

on architectonical principles, that is, its parts must be shown to possess an essential affinity, and be capable of

being deduced from one supreme and internal aim or end, which forms the condition of the possibility of the

scientific whole. The schema of a science must give a priori the plan of it (monogramma), and the division of

the whole into parts, in conformity with the idea of the science; and it must also distinguish this whole from

No one will attempt to construct a science, unless he have some idea to rest on as a proper basis. But, in the

elaboration of the science, he finds that the schema, nay, even the definition which he at first gave of the

science, rarely corresponds with his idea; for this idea lies, like a germ, in our reason, its parts undeveloped

and hid even from microscopical observation. For this reason, we ought to explain and define sciences, not

according to the description which the originator gives of them, but according to the idea which we find

based in reason itself, and which is suggested by the natural unity of the parts of the science already

accumulated. For it will of ten be found that the originator of a science and even his latest successors remain

attached to an erroneous idea, which they cannot render clear to themselves, and that they thus fail in

determining the true content, the articulation or systematic unity, and the limits of their science.

It is unfortunate that, only after having occupied ourselves for a long time in the collection of materials, under

the guidance of an idea which lies undeveloped in the mind, but not according to any definite plan of

arrangement nay, only after we have spent much time and labour in the technical disposition of our

materials, does it become possible to view the idea of a science in a clear light, and to project, according to

architectonical principles, a plan of the whole, in accordance with the aims of reason. Systems seem, like

certain worms, to be formed by a kind of generatio aequivoca by the mere confluence of conceptions, and to

gain completeness only with the progress of time. But the schema or germ of all lies in reason; and thus is not

only every system organized according to its own idea, but all are united into one grand system of human

knowledge, of which they form members. For this reason, it is possible to frame an architectonic of all human

cognition, the formation of which, at the present time, considering the immense materials collected or to be

found in the ruins of old systems, would not indeed be very difficult. Our purpose at present is merely to

sketch the plan of the architectonic of all cognition given by pure reason; and we begin from the point where

the main root of human knowledge divides into two, one of which is reason. By reason I understand here the

whole higher faculty of cognition, the rational being placed in contradistinction to the empirical.

If I make complete abstraction of the content of cognition, objectively considered, all cognition is, from a

subjective point of view, either historical or rational. Historical cognition is cognitio ex datis, rational,

cognitio ex principiis. Whatever may be the original source of a cognition, it is, in relation to the person who

possesses it, merely historical, if he knows only what has been given him from another quarter, whether that

knowledge was communicated by direct experience or by instruction. Thus the Person who has learned a

system of philosophy say the Wolfian although he has a perfect knowledge of all the principles,

definitions, and arguments in that philosophy, as well as of the divisions that have been made of the system,

possesses really no more than an historical knowledge of the Wolfian system; he knows only what has been

told him, his judgements are only those which he has received from his teachers. Dispute the validity of a

definition, and he is completely at a loss to find another. He has formed his mind on another's; but the

imitative faculty is not the productive. His knowledge has not been drawn from reason; and although,

objectively considered, it is rational knowledge, subjectively, it is merely historical. He has learned this or

that philosophy and is merely a plaster cast of a living man. Rational cognitions which are objective, that is,

which have their source in reason, can be so termed from a subjective point of view, only when they have

been drawn by the individual himself from the sources of reason, that is, from principles; and it is in this way

alone that criticism, or even the rejection of what has been already learned, can spring up in the mind.

All rational cognition is, again, based either on conceptions, or on the construction of conceptions. The

former is termed philosophical, the latter mathematical. I have already shown the essential difference of these

two methods of cognition in the first chapter. A cognition may be objectively philosophical and subjectively

historical as is the case with the majority of scholars and those who cannot look beyond the limits of their

system, and who remain in a state of pupilage all their lives. But it is remarkable that mathematical

knowledge, when committed to memory, is valid, from the subjective point of view, as rational knowledge

also, and that the same distinction cannot be drawn here as in the case of philosophical cognition. The reason

is that the only way of arriving at this knowledge is through the essential principles of reason, and thus it is

always certain and indisputable; because reason is employed in concreto but at the same time a priori that

is, in pure and, therefore, infallible intuition; and thus all causes of illusion and error are excluded. Of all the

a priori sciences of reason, therefore, mathematics alone can be learned. Philosophy unless it be in an

Philosophy is the system of all philosophical cognition. We must use this term in an objective sense, if we

understand by it the archetype of all attempts at philosophizing, and the standard by which all subjective

philosophies are to be judged. In this sense, philosophy is merely the idea of a possible science, which does

not exist in concreto, but to which we endeavour in various ways to approximate, until we have discovered

the right path to pursue a path overgrown by the errors and illusions of sense and the image we have

hitherto tried in vain to shape has become a perfect copy of the great prototype. Until that time, we cannot

learn philosophy it does not exist; if it does, where is it, who possesses it, and how shall we know it? We

can only learn to philosophize; in other words, we can only exercise our powers of reasoning in accordance

with general principles, retaining at the same time, the right of investigating the sources of these principles, of

Until then, our conception of philosophy is only a scholastic conception a conception, that is, of a system of

cognition which we are trying to elaborate into a science; all that we at present know being the systematic

unity of this cognition, and consequently the logical completeness of the cognition for the desired end. But

there is also a cosmical conception (conceptus cosmicus) of philosophy, which has always formed the true

basis of this term, especially when philosophy was personified and presented to us in the ideal of a

philosopher. In this view philosophy is the science of the relation of all cognition to the ultimate and essential

aims of human reason (teleologia rationis humanae), and the philosopher is not merely an artist who

occupies himself with conceptions but a lawgiver, legislating for human reason. In this sense of the word, it

would be in the highest degree arrogant to assume the title of philosopher, and to pretend that we had reached

The mathematician, the natural philosopher, and the logician how far soever the first may have advanced in

rational, and the two latter in philosophical knowledge are merely artists, engaged in the arrangement and

formation of conceptions; they cannot be termed philosophers. Above them all, there is the ideal teacher, who

employs them as instruments for the advancement of the essential aims of human reason. Him alone can we

call philosopher; but he nowhere exists. But the idea of his legislative power resides in the mind of every

man, and it alone teaches us what kind of systematic unity philosophy demands in view of the ultimate aims

*By a cosmical conception, I mean one in which all men necessarily take an interest; the aim of a science

must accordingly be determined according to scholastic conceptions, if it is regarded merely as a means to

In view of the complete systematic unity of reason, there can only be one ultimate end of all the operations of

the mind. To this all other aims are subordinate, and nothing more than means for its attainment. This

ultimate end is the destination of man, and the philosophy which relates to it is termed moral philosophy. The

superior position occupied by moral philosophy, above all other spheres for the operations of reason,

sufficiently indicates the reason why the ancients always included the idea and in an especial manner of

moralist in that of philosopher. Even at the present day, we call a man who appears to have the power of

selfgovernment, even although his knowledge may be very limited, by the name of philosopher.

The legislation of human reason, or philosophy, has two objects nature and freedom and thus contains not

only the laws of nature, but also those of ethics, at first in two separate systems, which, finally, merge into

one grand philosophical system of cognition. The philosophy of nature relates to that which is, that of ethics

But all philosophy is either cognition on the basis of pure reason, or the cognition of reason on the basis of

empirical principles. The former is termed pure, the latter empirical philosophy.

The philosophy of pure reason is either propaedeutic, that is, an inquiry into the powers of reason in regard to

pure a priori cognition, and is termed critical philosophy; or it is, secondly, the system of pure reason a

science containing the systematic presentation of the whole body of philosophical knowledge, true as well as

illusory, given by pure reason and is called metaphysic. This name may, however, be also given to the

whole system of pure philosophy, critical philosophy included, and may designate the investigation into the

sources or possibility of a priori cognition, as well as the presentation of the a priori cognitions which form a

system of pure philosophy excluding, at the same time, all empirical and mathematical elements.

Metaphysic is divided into that of the speculative and that of the practical use of pure reason, and is,

accordingly, either the metaphysic of nature, or the metaphysic of ethics. The former contains all the pure

rational principles based upon conceptions alone (and thus excluding mathematics) of all theoretical

cognition; the latter, the principles which determine and necessitate a priori all action. Now moral philosophy

alone contains a code of laws for the regulation of our actions which are deduced from principles entirely a

priori. Hence the metaphysic of ethics is the only pure moral philosophy, as it is not based upon

anthropological or other empirical considerations. The metaphysic of speculative reason is what is commonly

called metaphysic in the more limited sense. But as pure moral philosophy properly forms a part of this

system of cognition, we must allow it to retain the name of metaphysic, although it is not requisite that we

It is of the highest importance to separate those cognitions which differ from others both in kind and in

origin, and to take great care that they are not confounded with those with which they are generally found

connected. What the chemist does in the analysis of substances, what the mathematician in pure mathematics,

is, in a still higher degree, the duty of the philosopher, that the value of each different kind of cognition, and

the part it takes in the operations of the mind, may be clearly defined. Human reason has never wanted a

metaphysic of some kind, since it attained the power of thought, or rather of reflection; but it has never been

able to keep this sphere of thought and cognition pure from all admixture of foreign elements. The idea of a

science of this kind is as old as speculation itself; and what mind does not speculate either in the scholastic

or in the popular fashion? At the same time, it must be admitted that even thinkers by profession have been

unable clearly to explain the distinction between the two elements of our cognition the one completely a

priori, the other a posteriori; and hence the proper definition of a peculiar kind of cognition, and with it the

just idea of a science which has so long and so deeply engaged the attention of the human mind, has never

been established. When it was said: "Metaphysic is the science of the first principles of human cognition,"

this definition did not signalize a peculiarity in kind, but only a difference in degree; these first principles

were thus declared to be more general than others, but no criterion of distinction from empirical principles

was given. Of these some are more general, and therefore higher, than others; and as we cannot distinguish

what is completely a priori from that which is known to be a posteriori where shall we draw the line which

is to separate the higher and socalled first principles, from the lower and subordinate principles of

cognition? What would be said if we were asked to be satisfied with a division of the epochs of the world into

the earlier centuries and those following them? "Does the fifth, or the tenth century belong to the earlier

centuries?" it would be asked. In the same way I ask: Does the conception of extension belong to

metaphysics? You answer, "Yes." Well, that of body too? "Yes." And that of a fluid body? You stop, you are

unprepared to admit this; for if you do, everything will belong to metaphysics. From this it is evident that the

mere degree of subordination of the particular to the general cannot determine the limits of a science; and

that, in the present case, we must expect to find a difference in the conceptions of metaphysics both in kind

and in origin. The fundamental idea of metaphysics was obscured on another side by the fact that this kind of

a priori cognition showed a certain similarity in character with the science of mathematics. Both have the

property in common of possessing an a priori origin; but, in the one, our knowledge is based upon

conceptions, in the other, on the construction of conceptions. Thus a decided dissimilarity between

philosophical and mathematical cognition comes out a dissimilarity which was always felt, but which could

not be made distinct for want of an insight into the criteria of the difference. And thus it happened that, as

philosophers themselves failed in the proper development of the idea of their science, the elaboration of the

science could not proceed with a definite aim, or under trustworthy guidance. Thus, too, philosophers,

ignorant of the path they ought to pursue and always disputing with each other regarding the discoveries

which each asserted he had made, brought their science into disrepute with the rest of the world, and finally,

All pure a priori cognition forms, therefore, in view of the peculiar faculty which originates it, a peculiar and

distinct unity; and metaphysic is the term applied to the philosophy which attempts to represent that cognition

in this systematic unity. The speculative part of metaphysic, which has especially appropriated this

appellation that which we have called the metaphysic of nature and which considers everything, as it is

(not as it ought to be), by means of a priori conceptions, is divided in the following manner.

Metaphysic, in the more limited acceptation of the term, consists of two parts transcendental philosophy and

the physiology of pure reason. The former presents the system of all the conceptions and principles belonging

to the understanding and the reason, and which relate to objects in general, but not to any particular given

objects (Ontologia); the latter has nature for its subjectmatter, that is, the sum of given objects whether

given to the senses, or, if we will, to some other kind of intuition and is accordingly physiology, although

only rationalis. But the use of the faculty of reason in this rational mode of regarding nature is either physical

or hyperphysical, or, more properly speaking, immanent or transcendent. The former relates to nature, in so

far as our knowledge regarding it may be applied in experience (in concreto); the latter to that connection of

the objects of experience, which transcends all experience. Transcendent physiology has, again, an internal

and an external connection with its object, both, however, transcending possible experience; the former is the

physiology of nature as a whole, or transcendental cognition of the world, the latter of the connection of the

Immanent physiology, on the contrary, considers nature as the sum of all sensuous objects, consequently, as it

is presented to us but still according to a priori conditions, for it is under these alone that nature can be

presented to our minds at all. The objects of immanent physiology are of two kinds: 1. Those of the external

senses, or corporeal nature; 2. The object of the internal sense, the soul, or, in accordance with our

fundamental conceptions of it, thinking nature. The metaphysics of corporeal nature is called physics; but, as

it must contain only the principles of an a priori cognition of nature, we must term it rational physics. The

metaphysics of thinking nature is called psychology, and for the same reason is to be regarded as merely the

Thus the whole system of metaphysics consists of four principal parts: 1. Ontology; 2. Rational Physiology;

3. Rational cosmology; and 4. Rational theology. The second part that of the rational doctrine of nature

*It must not be supposed that I mean by this appellation what is generally called physica general is, and

which is rather mathematics than a philosophy of nature. For the metaphysic of nature is completely different

from mathematics, nor is it so rich in results, although it is of great importance as a critical test of the

application of pure understandingcognition to nature. For want of its guidance, even mathematicians,

adopting certain common notions which are, in fact, metaphysical have unconsciously crowded their

theories of nature with hypotheses, the fallacy of which becomes evident upon the application of the

principles of this metaphysic, without detriment, however, to the employment of mathematics in this sphere

The fundamental idea of a philosophy of pure reason of necessity dictates this division; it is, therefore,

architectonical in accordance with the highest aims of reason, and not merely technical, or according to

certain accidentallyobserved similarities existing between the different parts of the whole science. For this

reason, also, is the division immutable and of legislative authority. But the reader may observe in it a few

points to which he ought to demur, and which may weaken his conviction of its truth and legitimacy.

In the first place, how can I desire an a priori cognition or metaphysic of objects, in so far as they are given a

posteriori? and how is it possible to cognize the nature of things according to a priori principles, and to attain

to a rational physiology? The answer is this. We take from experience nothing more than is requisite to

present us with an object (in general) of the external or of the internal sense; in the former case, by the mere

conception of matter (impenetrable and inanimate extension), in the latter, by the conception of a thinking

being given in the internal empirical representation, I think. As to the rest, we must not employ in our

metaphysic of these objects any empirical principles (which add to the content of our conceptions by means

of experience), for the purpose of forming by their help any judgements respecting these objects.

Secondly, what place shall we assign to empirical psychology, which has always been considered a part of

metaphysics, and from which in our time such important philosophical results have been expected, after the

hope of constructing an a priori system of knowledge had been abandoned? I answer: It must be placed by the

side of empirical physics or physics proper; that is, must be regarded as forming a part of applied philosophy,

the a priori principles of which are contained in pure philosophy, which is therefore connected, although it

must not be confounded, with psychology. Empirical psychology must therefore be banished from the sphere

of metaphysics, and is indeed excluded by the very idea of that science. In conformity, however, with

scholastic usage, we must permit it to occupy a place in metaphysics but only as an appendix to it. We adopt

this course from motives of economy; as psychology is not as yet full enough to occupy our attention as an

independent study, while it is, at the same time, of too great importance to be entirely excluded or placed

where it has still less affinity than it has with the subject of metaphysics. It is a stranger who has been long a

guest; and we make it welcome to stay, until it can take up a more suitable abode in a complete system of

The above is the general idea of metaphysics, which, as more was expected from it than could be looked for

with justice, and as these pleasant expectations were unfortunately never realized, fell into general disrepute.

Our Critique must have fully convinced the reader that, although metaphysics cannot form the foundation of

religion, it must always be one of its most important bulwarks, and that human reason, which naturally

pursues a dialectical course, cannot do without this science, which checks its tendencies towards dialectic

and, by elevating reason to a scientific and clear selfknowledge, prevents the ravages which a lawless

speculative reason would infallibly commit in the sphere of morals as well as in that of religion. We may be

sure, therefore, whatever contempt may be thrown upon metaphysics by those who judge a science not by its

own nature, but according to the accidental effects it may have produced, that it can never be completely

abandoned, that we must always return to it as to a beloved one who has been for a time estranged, because

the questions with which it is engaged relate to the highest aims of humanity, and reason must always labour

either to attain to settled views in regard to these, or to destroy those which others have already established.

Metaphysic, therefore that of nature, as well as that of ethics, but in an especial manner the criticism which

forms the propaedeutic to all the operations of reason forms properly that department of knowledge which

may be termed, in the truest sense of the word, philosophy. The path which it pursues is that of science,

which, when it has once been discovered, is never lost, and never misleads. Mathematics, natural science, the

common experience of men, have a high value as means, for the most part, to accidental ends but at last

also, to those which are necessary and essential to the existence of humanity. But to guide them to this high

goal, they require the aid of rational cognition on the basis of pure conceptions, which, be it termed as it may,

For the same reason, metaphysics forms likewise the completion of the culture of human reason. In this

respect, it is indispensable, setting aside altogether the influence which it exerts as a science. For its

subjectmatter is the elements and highest maxims of reason, which form the basis of the possibility of some

sciences and of the use of all. That, as a purely speculative science, it is more useful in preventing error than

in the extension of knowledge, does not detract from its value; on the contrary, the supreme office of censor

which it occupies assures to it the highest authority and importance. This office it administers for the purpose

of securing order, harmony, and wellbeing to science, and of directing its noble and fruitful labours to the

This title is placed here merely for the purpose of designating a division of the system of pure reason of

which I do not intend to treat at present. I shall content myself with casting a cursory glance, from a purely

transcendental point of view that of the nature of pure reason on the labours of philosophers up to the

present time. They have aimed at erecting an edifice of philosophy; but to my eye this edifice appears to be in

It is very remarkable, although naturally it could not have been otherwise, that, in the infancy of philosophy,

the study of the nature of God and the constitution of a future world formed the commencement, rather than

the conclusion, as we should have it, of the speculative efforts of the human mind. However rude the

religious conceptions generated by the remains of the old manners and customs of a less cultivated time, the

intelligent classes were not thereby prevented from devoting themselves to free inquiry into the existence and

nature of God; and they easily saw that there could be no surer way of pleasing the invisible ruler of the

world, and of attaining to happiness in another world at least, than a good and honest course of life in this.

Thus theology and morals formed the two chief motives, or rather the points of attraction in all abstract

inquiries. But it was the former that especially occupied the attention of speculative reason, and which

I shall not at present indicate the periods of time at which the greatest changes in metaphysics took place, but

shall merely give a hasty sketch of the different ideas which occasioned the most important revolutions in this

sphere of thought. There are three different ends in relation to which these revolutions have taken place.

1. In relation to the object of the cognition of reason, philosophers may be divided into sensualists and

intellectualists. Epicurus may be regarded as the head of the former, Plato of the latter. The distinction here

signalized, subtle as it is, dates from the earliest times, and was long maintained. The former asserted that

reality resides in sensuous objects alone, and that everything else is merely imaginary; the latter, that the

senses are the parents of illusion and that truth is to be found in the understanding alone. The former did not

deny to the conceptions of the understanding a certain kind of reality; but with them it was merely logical,

with the others it was mystical. The former admitted intellectual conceptions, but declared that sensuous

objects alone possessed real existence. The latter maintained that all real objects were intelligible, and

believed that the pure understanding possessed a faculty of intuition apart from sense, which, in their opinion,

2. In relation to the origin of the pure cognitions of reason, we find one school maintaining that they are

derived entirely from experience, and another that they have their origin in reason alone. Aristotle may be

regarded as the bead of the empiricists, and Plato of the noologists. Locke, the follower of Aristotle in

modern times, and Leibnitz of Plato (although he cannot be said to have imitated him in his mysticism), have

not been able to bring this question to a settled conclusion. The procedure of Epicurus in his sensual system,

in which he always restricted his conclusions to the sphere of experience, was much more consequent than

that of Aristotle and Locke. The latter especially, after having derived all the conceptions and principles of

the mind from experience, goes so far, in the employment of these conceptions and principles, as to maintain

that we can prove the existence of God and the existence of God and the immortality of them objects lying

beyond the soul both of them of possible experience with the same force of demonstration as any

3. In relation to method. Method is procedure according to principles. We may divide the methods at present

employed in the field of inquiry into the naturalistic and the scientific. The naturalist of pure reason lays it

down as his principle that common reason, without the aid of science which he calls sound reason, or

common sense can give a more satisfactory answer to the most important questions of metaphysics than

speculation is able to do. He must maintain, therefore, that we can determine the content and circumference

of the moon more certainly by the naked eye, than by the aid of mathematical reasoning. But this system is

mere misology reduced to principles; and, what is the most absurd thing in this doctrine, the neglect of all

scientific means is paraded as a peculiar method of extending our cognition. As regards those who are

naturalists because they know no better, they are certainly not to be blamed. They follow common sense,

without parading their ignorance as a method which is to teach us the wonderful secret, how we are to find

Arcesilas aerumnosique Solones. PERSIUS* is their motto, under which they may lead a pleasant and praise

worthy life, without troubling themselves with science or troubling science with them.

*[Satirae, iii. 7879. "What I know is enough for I don't care to be what Arcesilas was, and the wretched

As regards those who wish to pursue a scientific method, they have now the choice of following either the

dogmatical or the sceptical, while they are bound never to desert the systematic mode of procedure. When I

mention, in relation to the former, the celebrated Wolf, and as regards the latter, David Hume, I may leave, in

accordance with my present intention, all others unnamed. The critical path alone is still open. If my reader

has been kind and patient enough to accompany me on this hitherto untravelled route, he can now judge

whether, if he and others will contribute their exertions towards making this narrow footpath a high road of

thought, that which many centuries have failed to accomplish may not be executed before the close of the

present namely, to bring Reason to perfect contentment in regard to that which has always, but without

permanent results, occupied her powers and engaged her ardent desire for knowledge.

8. II. The Human Intellect, even in an Unphilosophical State, is in Possession of Certain Cognitions "a priori"., page = 21

9. III. Philosophy stands in need of a Science which shall Determine the Possibility, Principles, and Extent of Human Knowledge "a priori", page = 22

10. IV. Of the Difference Between Analytical and Synthetical Judgements., page = 23

11. V. In all Theoretical Sciences of Reason, Synthetical Judgements "a priori" are contained as Principles., page = 24

13. VII. Idea and Division of a Particular Science, under the Name of a Critique of Pure Reason., page = 28

26. Transcendental Logic. FIRST DIVISION. TRANSCENDENTAL ANALYTIC. SS I., page = 45

29. CHAPTER I. Of the Transcendental Clue to the Discovery of all Pure Conceptions of the Understanding., page = 46

33. SECTION II. Of the Logical Function of the Understanding in Judgements. , page = 47

35. SECTION III. Of the Pure Conceptions of the Understanding, or Categories., page = 49

39. CHAPTER II Of the Deduction of the Pure Conceptions of the Understanding., page = 54

40. SECTION I Of the Principles of a Transcendental Deduction in general. , page = 54

42. Transition to the Transcendental Deduction of the Categories. SS 10, page = 56

43. SECTION II Transcendental Deduction of the pure Conceptions of the Understanding. , page = 58

44. SS 11 Of the Possibility of a Conjunction of the manifold representations given by Sense., page = 58

46. The Principle of the Synthetical Unity of Apperception is the highest Principle of all exercise of the Understanding. SS 13, page = 60

48. The Logical Form of all Judgements consists in the Objective Unity of Apperception of the Conceptions contained therein. SS 15, page = 61

49. All Sensuous Intuitions are subject to the Categories, as Conditions under which alone the manifold Content of them can be united in one Consciousness. SS 16, page = 62

51. In Cognition, its Application to Objects of Experience is the only legitimate use of the Category. SS 18, page = 63

53. Of the Application of the Categories to Objects of the Senses in general. SS 20, page = 64

55. Result of this Deduction of the Conceptions of the Understanding. SS 23, page = 68

57. CHAPTER I. Of the Schematism at of the Pure Conceptions of the Understanding., page = 71

59. SECTION I. Of the Supreme Principle of all Analytical Judgements., page = 76

60. SECTION II. Of the Supreme Principle of all Synthetical Judgements., page = 77

61. SECTION III. Systematic Representation of all Synthetical Principles of the Pure Understanding., page = 78

62. CHAPTER III Of the Ground of the Division of all Objects into Phenomena and Noumena., page = 108

73. SECTION III. Of the Interest of Reason in these Self-contradictions., page = 164

74. SECTION IV. Of the necessity imposed upon Pure Reason of presenting a Solution of its Transcendental Problems., page = 168

75. SECTION V. Sceptical Exposition of the Cosmological Problems presented in the four Transcendental Ideas., page = 171

76. SECTION VI. Transcendental Idealism as the Key to the Solution of Pure Cosmological Dialectic., page = 173

78. SECTION VIII. Regulative Principle of Pure Reason in relation to the Cosmological Ideas., page = 177

79. SECTION IX. Of the Empirical Use of the Regulative Principle of Reason with regard to the Cosmological Ideas., page = 179

82. SECTION II. Of the Transcendental Ideal (Prototypon Trancendentale)., page = 195

83. SECTION III. Of the Arguments employed by Speculative Reason in Proof of the Existence of a Supreme Being., page = 199

84. SECTION IV. Of the Impossibility of an Ontological Proof of the Existence of God., page = 201

85. SECTION V. Of the Impossibility of a Cosmological Proof of the Existence of God., page = 205

86. SECTION VI. Of the Impossibility of a Physico-Theological Proof., page = 210

87. SECTION VII. Critique of all Theology based upon Speculative Principles of Reason., page = 213

89. SECTION I. The Discipline of Pure Reason in the Sphere of Dogmatism., page = 236

92. SECTION IV. The Discipline of Pure Reason in Relation to Proofs., page = 256

95. SECTION II. Of the Ideal of the Summum Bonum as a Determining Ground of the Ultimate End of Pure Reason., page = 262