The Online Library of Liberty

A project of Liberty Fund, Inc.

• Dedication
• Preface 1
• Translator’s Preface
• Translator’s Preface to Second Edition
• Introduction [p. 1]
• I: The Idea of Transcendental Philosophy
• II: Division of Transcendental Philosophy
• I: The Elements of Transcendentalism
• Part I: Transcendental Æsthetic [p. 19]
• Section I: Of Space
• Section II: Of Time
• Part II: Transcendental Logic [p. 50]
• Introduction the Idea of a Transcendental Logic
• I: Of Logic In General
• II: Of Transcendental Logic
• III: Of the Division of General Logic Into Analytic and Dialectic
• IV: Of the Division of Transcendental Logic Into Transcendental Analytic and Dialectic
• Division I: Transcendental Analytic In Two Books, With Their Chapters and Sections
• Book I: Analytic of Concepts
• Chapter I: Method of Discovering All Pure Concepts of the Understanding
• Section I: Of the Logical Use of the Understanding In General
• Section II: Of the Logical Function of the Understanding In Judgments [p. 70]
• Section III: Of the Pure Concepts of the Understanding, Or of the Categories
• Chapter II: Of the Deduction of the Pure Concepts of the Understanding [p. 84]
• Section I: Of the Principles of a Transcendental Deduction In General
• Section II: Of the a Priori Grounds For the Possibility of Experience
• I: Of the Synthesis of Apprehension In Intuition
• II: Of the Synthesis of Reproduction In Imagination
• III: Of the Synthesis of Recognition In Concepts [p. 103]
• IV: Preliminary Explanation of the Possibility of the Categories As Knowledge a Priori
• Section III: Of the Relation of the Understanding to Objects In General, and the Possibility of Knowing Them a Priori [p. 115]
• Book II: Analytic of Principles
• Introduction of the Transcendental Faculty of Judgment In General
• Chapter I: Of the Schematism of the Pure Concepts of the Understanding [p. 137]
• Chapter II: System of All Principles of the Pure Understanding [p. 148]
• Section I: Of the Highest Principle of All Analytical Judgments
• Section II: Of the Highest Principle of All Synthetical Judgments [p. 154]
• Section III: Systematical Representation of All Synthetical Principles of the Understanding
• I: [of the Axioms of Intuition 1 Principle of the Pure Understanding
• II: [ Anticipations of Perception
• III: [ the Analogies of Experience
• IV: The Postulates of Empirical Thought In General
• Chapter III: On the Ground of Distinction of All Subjects Into Phenomena and Noumena
• I.: Identity and Difference
• II.: Agreement and Opposition
• III.: The Internal and the External
• IV.: Matter and Form
• Note On the Amphiboly of Reflective Concepts
• Division II: Transcendental Dialectic In Two Books, With Their Chapters and Sections [p. 293]
• Introduction: 1.
• Book I: Of the Concepts of Pure Reason [p. 310]
• First Section of Ideas In General
• Second Section of Transcendental Ideas [p. 321]
• Third Section System of Transcendental Ideas [p. 333]
• Book II: Of the Dialectical Conclusions of Pure Reason
• Chapter I: Of the Paralogisms of Pure Reason [p. 341]
• Chapter II: The Antinomy of Pure Reason
• Section I: System of Cosmological Ideas
• Section II: Antithetic of Pure Reason
• Section III: Of the Interest of Reason In These Conflicts [p. 462]
• Section IV: Of the Transcendental Problems of Pure Reason, and the Absolute Necessity of Their Solution
• Section V: Sceptical Representation of the Cosmological Questions In the Four Transcendental Ideas [p. 485]
• Section VI: Transcendental Idealism As the Key to the Solution of Cosmological Dialectic
• Section VII: Critical Decision of the Cosmological Conflict of Reason With Itself
• Section VIII: The Regulative Principle of Pure Reason With Regard to the Cosmological Ideas [p. 508]
• Section IX: Of the Empirical Use of the Regulative Principle of Reason With Regard to All Cosmological Ideas
• Chapter III: The Ideal of Pure Reason
• Section I: Of the Ideal In General
• Section II: Of the Transcendental Ideal ( Prototypon Transcendentale )
• Section III: Of the Arguments of Speculative Reason In Proof of the Existence of a Supreme Being
• Section IV: Of the Impossibility of an Ontological Proof of the Existence of God [p. 592]
• Section V: Of the Impossibility of a Cosmological Proof of the Existence of God [p. 603]
• Section VI: Of the Impossibility of the Physico-theological Proof
• Section VII: Criticism of All Theology Based On Speculative Principles of Reason [p. 631]
• Chapter I: The Discipline of Pure Reason
• Section I: The Discipline of Pure Reason In Its Dogmatical Use
• Section II: The Discipline of Pure Reason In Its Polemical Use
• Section III: The Discipline of Pure Reason With Regard to Hypotheses
• Section IV: The Discipline of Pure Reason With Regard to Its Proofs
• Chapter II: The Canon of Pure Reason [p. 795]
• First Section: of the Ultimate Aim of the Pure Use of Our Reason
• Section II: Of the Ideal of the Summum Bonum As Determining the Ultimate Aim of Pure Reason
• Section III: Of Trowing, Knowing, and Believing [p. 820]
• Chapter III: The Architectonic of Pure Reason [p. 832]
• Chapter IV: The History of Pure Reason [p. 852]
• Supplement I: Motto to Second Edition
• Supplement II: Preface to the Second Edition. 1787. [p. Vii]
• Supplement III: Supplement Iv
• Supplement V
• Supplement Vi
• Supplement V
• Supplement Vi
• Supplement Vii
• Supplement Viii
• Supplement Ix
• Supplement X
• Supplement Xi
• Supplement Xii
• Supplement Xiii
• Supplement Xiv
• Supplement Xv
• Supplement Xvi a
• Supplement Xvi B
• Supplement Xvii
• Supplement Xviii
• Supplement Xix
• Supplement Xx
• Supplement Xxi
• Supplement Xxii
• Supplement Xxiii
• Supplement Xxiv
• Supplement Xxv
• Supplement Xxvi
• Supplement Xxvii
• Supplement Xxviii

IV

The Postulates of Empirical Thought in General

Explanation [p. 219]

The categories of modality have this peculiar character that, as determining an object, they do not enlarge in the least the concept to which they are attached as predicates, but express only a relation to our faculty of knowledge. Even when the concept of a thing is quite complete, I can still ask with reference to that object, whether it is possible only, or real also, and, if the latter, whether it is necessary? No new determinations of the object are thereby conceived, but it is only asked in what relation it (with all its determinations) stands to the understanding and its empirical employment, to the empirical faculty of judgment, and to reason, in its application to experience?

The principles of modality are therefore nothing but explanations of the concepts of possibility, reality, and necessity, in their empirical employment, confining all categories to an empirical employment only, and prohibiting their transcendental1 use. For if these categories are not to have a purely logical character, expressing the forms of thought analytically, but are to refer to things, their possibility, reality, or necessity, they must have reference to possible experience and its synthetical unity, in which alone objects of knowledge can be given.

The postulate of the possibility of things [p. 220] demands that the concept of these should agree with the formal conditions of experience in general. This, the objective form of experience in general, contains all synthesis which is required for a knowledge of objects. A concept is to be considered as empty, and as referring to no object, if the synthesis which it contains does not belong to experience, whether as borrowed from it (in which case it is called an empirical concept), or as a synthesis on which, as a condition a priori, all experience (in its form) depends, in which case it is a pure concept, but yet belonging to experience, because its object can only be found in it. For whence could the character of the possibility of an object, which can be conceived by a synthetical concept a priori, be derived, except from the synthesis which constitutes the form of all empirical knowledge of objects? It is no doubt a necessary logical condition, that such a concept must contain nothing contradictory, but this is by no means sufficient to establish the objective reality of a concept, that is, the possibility of such an object, as is conceived by a concept. Thus in the concept of a figure to be enclosed between two straight lines, there is nothing contradictory, because the concepts of two straight lines and their meeting contain no negation of a figure. [p. 221] The impossibility depends, not on the concept itself, but on its construction in space, that is, the conditions of space and its determinations, and it is these that have objective reality, or apply to possible things, because they contain a priori in themselves the form of experience in general.

And now we shall try to explain the manifold usefulness and influence of this postulate of possibility. If I represent to myself a thing that is permanent, while everything which changes belongs merely to its state, I can never know from such a concept by itself that a thing of that kind is possible. Or, if I represent to myself something so constituted that, when it is given, something else must at all times and inevitably follow upon it, this may no doubt be conceived without contradiction, but we have as yet no means of judging whether such a quality, viz. causality, is to be met with in any possible object. Lastly, I can very well represent to myself different things (substances) so constituted, that the state of the one produces an effect on the state of the other, and this reciprocally; but whether such a relation can belong to any things cannot be learned from these concepts which contain a purely arbitrary synthesis. The objective reality of these concepts is only known when we see that they [p. 222] express a priori the relations of perceptions in every kind of experience; and this objective reality, that is, their transcendental truth, though independent of all experience, is nevertheless not independent of all relation to the form of experience in general, and to that synthetical unity in which alone objects can be known empirically.

But if we should think of framing new concepts of substances, forces, and reciprocal actions out of the material supplied to us by our perceptions, without borrowing from experience the instance of their connection, we should entangle ourselves in mere cobwebs of our brain, the possibility of which could not be tested by any criteria, because in forming them we were not guided by experience, nor had borrowed these concepts from it. Such purely imaginary concepts cannot receive the character of possibility, like the categories a priori, as conditions on which all experience depends, but only a posteriori, as concepts that must be given by experience, so that their possibility can either not be known at all, or a posteriori, and empirically only. Thus, for instance, a substance supposed to be present as permanent in space, and yet not filling it (like that something between matter and the thinking subject, which some have tried to introduce), or a peculiar faculty of our mind, by which we can see (not only infer) the future, or lastly, another faculty, by which we can enter into a community of thought with other men (however distant they may be), all these are concepts the [p. 223] possibility of which has nothing to rest on, because it is not founded on experience and its known laws. Without these they are and can only be arbitrary combinations of thought which, though they contain nothing contradictory in themselves, have no claim to objective reality, or to the possibility of such an object as is to be conceived by them. With regard to reality, it stands to reason that we cannot conceive it in the concrete without the aid of experience; for reality concerns sensation only, as the material of experience, and not the form of relations, which might to a certain extent allow us to indulge in mere fancies.

I here pass by everything the possibility of which can only be learned from its reality in experience, and I only mean to consider the possibility of things through concepts a priori. Of these (concepts) I persist in maintaining that they can never exist as such concepts by themselves alone, but only as formal and objective conditions of experience in general.1

It might seem indeed as if the possibility of a triangle could be known from its concept by itself (being independent of all experience), for we can give to it an object entirely a priori, that is, we can construct it. But as this is only the form of an object, it would always remain a product of the imagination only. The possibility [p. 224] of its object would remain doubtful, because more is wanted to establish it, namely, that such a figure should really be conceived under all those conditions on which all objects of experience depend. That which alone connects with this concept the representation of the possibility of such a thing, is the fact that space is a formal condition a priori of all external experiences, and that the same formative synthesis, by which we construct a triangle in imagination, should be identical with that which we exercise in the apprehension of a phenomenon, in order to make an empirical concept of it. And thus the possibility of continuous quantities, nay, of all quantities, the concepts of which are always synthetical, can never be deduced from the concepts themselves, but only from them, as formal conditions of the determination of objects in all experience. And where indeed should we look for objects, corresponding to our concepts, except in experience, by which alone objects are given us? If we are able to know and determine the possibility of things without any previous experience, this is only with reference to those formal conditions under which anything may become an object in experience. This takes place entirely a priori, but nevertheless in constant reference to experience, and within its limits.

The postulate concerning our knowledge of [p. 225] the reality of things, requires perception, therefore sensation and consciousness of it, not indeed immediately of the object itself, the existence of which is to be known, but yet of a connection between it and some real perception, according to the analogies of experience which determine in general all real combinations in experience.

In the mere concept of a thing no sign of its existence can be discovered. For though the concept be ever so perfect, so that nothing should be wanting in it to enable us to conceive the thing with all its own determinations, existence has nothing to do with all this. It depends only on the question whether such a thing be given us, so that its perception may even precede its concept. A concept preceding experience implies its possibility only, while perception, which supplies the material of a concept, is the only characteristic of reality. It is possible, however, even before the perception of a thing, and therefore, in a certain sense, a priori, to know its existence, provided it hang together with some other perceptions, according to the principles of their empirical connection (analogies). For in that case the existence of a thing hangs together at least with our perceptions in a possible experience, and guided by our analogies we [p. 226] can, starting from our real experience, arrive at some other thing in the series of possible perceptions. Thus we know the existence of some magnetic matter pervading all bodies from the perception of the attracted iron filings, though our organs are so constituted as to render an immediate perception of that matter impossible. According to the laws of sensibility and the texture of our perceptions, we ought in our experience to arrive at an immediate empirical intuition of that magnetic matter, if only our senses were more acute, for their actual obtuseness does not concern the form of possible experience. Wherever, therefore, perception and its train can reach, according to empirical laws, there our knowledge also of the existence of things can reach. But if we do not begin with experience, or do not proceed according to the laws of the empirical connection of phenomena, we are only making a vain display, as if we could guess and discover the existence of anything.1

With reference to the third postulate we find that it refers to the material necessity in existence, and not to the merely formal and logical necessity in the connection of concepts. As it is impossible that the existence of the objects of the senses should ever be known entirely a priori, though it may be known to a certain extent a priori, namely, with reference to another already given existence, and as even in that case we can only [p. 227] arrive at such an existence as must somewhere be contained in the whole of the experience of which the given perception forms a part, it follows that the necessity of existence can never be known from concepts, but always from the connection only with what is actually perceived, according to general rules of experience.2 Now, there is no existence that can be known as necessary under the condition of other given phenomena, except the existence of effects from given causes, according to the laws of causality. It is not therefore the existence of things (substances), but the existence of their state, of which alone we can know the necessity, and this from other states only, which are given in perception, and according to the empirical laws of causality. Hence it follows that the criterium of necessity can only be found in the law of possible experience, viz. that everything that happens is determined a priori by its cause in phenomena.1 We therefore know in nature the necessity of those effects only of which the causes are given, and the character of necessity in existence never goes beyond the field of possible experience, and even there it does not apply to the existence of things, as substances, because such substances can never be looked upon as empirical effects or as something that happens and arises. Necessity, therefore, affects only the relations of phenomena [p. 228] according to the dynamical law of causality, and the possibility, dependent upon it, of concluding a priori from a given existence (of a cause) to another existence (that of an effect). Thus the principle that everything which happens is hypothetically necessary, subjects all the changes in the world to a law, that is, to a rule of necessary existence, without which there would not even be such a thing as nature. Hence the proposition that nothing happens by blind chance (in mundo non datur casus) is an a priori law of nature, and so is likewise the other, that no necessity in nature is a blind, but always a conditional and therefore an intelligible, necessity (non datur fatum). Both these are laws by which the mere play of changes is rendered subject to a nature of things (as phenomena), or what is the same, to that unity of the understanding in which alone they can belong to experience, as the synthetical unity of phenomena. Both are dynamical principles. The former is in reality a consequence of the principle of causality (the second of the analogies of experience). The latter is one of the principles of modality, which to the determination of causality adds the concept of necessity, which itself is subject to a rule of the understanding. The principle of continuity rendered every break in the series of phenomena (changes) impossible (in mundo non datur saltus), and likewise any gap between two [p. 229] phenomena in the whole of our empirical intuitions in space (non datur hiatus). For so we may express the proposition that nothing can enter into experience to prove a vacuum, or even to admit it as a possible part of empirical synthesis. For the vacuum, which one may conceive as outside the field of possible experience (the world), can never come before the tribunal of the understanding which has to decide on such questions only as concern the use to be made of given phenomena for empirical knowledge. It is in reality a problem of that ideal reason which goes beyond the sphere of a possible experience, and wants to form an opinion of that which surrounds and limits experience, and will therefore have to be considered in our transcendental Dialectic. With regard to the four propositions (in mundo non datur hiatus, non datus saltus, non datur casus, non datur fatum), it would be easy to represent each of them, as well as all principles of a transcendental origin, according to the order of the categories, and thus to assign its proper place to every one of them. But, after what has been said before, the versed and expert reader will find it easy to do this himself, and to discover the proper method for it. They all simply agree in this, that they admit nothing in our empirical synthesis that would in any way run counter to the understanding, and to the continuous cohesion of all phenomena, that is, to the unity of its concepts. For it is the understanding [p. 230] alone through which the unity of experience, in which all perceptions must have their place, becomes possible.

Whether the field of possibility be larger than the field which contains everything which is real, and whether this again be larger than the field of what is necessary, are curious questions and admitting of a synthetical solution, which questions however are to be brought before the tribunal of reason only. They really come to this, whether all things, as phenomena, belong to the sphere of one experience, of which every given perception forms a part, that could not be connected with any other phenomena, or whether my perceptions can ever belong to more than one possible experience (in its general connection). The understanding in reality does nothing but give to experience a rule a priori, according to the subjective and formal conditions of sensibility and apperception, which alone render experience possible. Other forms of intuition (different from space and time), and other forms of the understanding (different from the discursive forms of thought or conceptual knowledge), even if they were possible, we could in no wise render conceivable or intelligible to ourselves; and even if we could, they would never belong to experience, the only field of knowledge in which objects are given to us. Whether there be [p. 231] therefore other perceptions but those that belong to our whole possible experience, whether there be in fact a completely new field of matter, can never be determined by the understanding, which is only concerned with the synthesis of what is given.

The poverty of the usual arguments by which we construct a large empire of possibility of which all that is real (the objects of experience) forms but a small segment, is but too apparent. When we say that all that is real is possible, we arrive, according to the logical rules of inversion, at the merely particular proposition that some possible is real, and thus seem to imply that much is possible that is not real. Nay, it seems as if we might extend the number of things possible beyond that of things real, simply on the ground that something must be added to the possible to make it real. But this addition to the possible I cannot recognise, because what would thus be added to the possible, would be really the impossible. It is only to my understanding that anything can be added concerning the agreement with the formal conditions of experience, and what can be added is the connection with some perception; and whatever is connected with such a perception, according to empirical laws, is real, though it may not be perceived immediately. But that, in constant connection with what is given us in experience, [p. 232] there should be another series of phenomena, and therefore more than one all-embracing experience, cannot possibly be concluded from what is given us, and still less, if nothing is given us, because nothing can be thought without some kind of material. What is possible only under conditions which themselves are possible only, is not possible in the full sense of the word, not therefore in the sense in which we ask whether the possibility of things can extend beyond the limits of experience.

I have only touched on these questions in order to leave no gap in what are commonly supposed to be the concepts of the understanding. But absolute possibility (which has no regard for the formal conditions of experience) is really no concept of the understanding, and can never be used empirically, but belongs to reason alone, which goes beyond all possible empirical use of the understanding. We have therefore made these few critical remarks only, leaving the subject itself unexplained for the present.

And here, when I am on the point of concluding this fourth number and at the same time the system of all principles of the pure understanding, I think I ought to explain why I call the principles of modality postulates. I do not take this term in the sense which has [p. 233] been given to it by some modern philosophical writers, and which is opposed to the sense in which mathematicians take it, viz. that to postulate should mean to represent a proposition as certain without proof or justification; for if we were to admit with regard to synthetical propositions, however evident they may appear, that they should meet with unreserved applause, without any deduction, and on their own authority only, all criticism of the understanding would be at an end. And as there is no lack of bold assertions, which public opinion does not decline to accept, (this acceptance being, however, no credential), our understanding would be open to every fancy, and could not refuse its sanction to claims which demand admission as real axioms in the same confident tone, though without any substantial reasons. If therefore a condition a priori is to be synthetically joined to the concept of a thing, it will be indispensable that, if not a proof, at least a deduction of the legitimacy of such an assertion, should be forthcoming.

The principles of modality, however, are not objectively synthetical, because the predicates of possibility, reality, and necessity do not in the least increase the concept of which they are predicated, by adding anything to its representation. But as nevertheless they are synthetical, they are so subjectively only, i.e. they add to the [p. 234] concept of a (real) thing, without predicating anything new, the peculiar faculty of knowledge from which it springs and on which it depends, so that, if in the understanding the concept is only connected with the formal conditions of experience, its object is called possible; if it is connected with perception (sensation as the material of the senses), and through it determined by the understanding, its object is called real; while, if it is determined through the connection of perceptions, according to concepts, its object is called necessary. The principles of modality therefore predicate nothing of a concept except the act of the faculty of knowledge by which it is produced. In mathematics a postulate means a practical proposition, containing nothing but a synthesis by which we first give an object to ourselves and produce its concept, as if, for instance, we draw a circle with a given line from a given point in the plane. Such a proposition cannot be proved, because the process required for it is the very process by which we first produce the concept of such a figure. We may therefore with the same right postulate the principles of modality, because they never increase1 the concept of a thing, but indicate the manner only in which the concept was joined with our faculty of knowledge.1 [p. 235]

CHAPTER III

ON THE GROUND OF DISTINCTION OF ALL SUBJECTS INTO PHENOMENA AND NOUMENA

We have now not only traversed the whole domain of the pure understanding, and carefully examined each part of it, but we have also measured its extent, and assigned to everything in it its proper place. This domain, however, is an island and enclosed by nature itself within limits that can never be changed. It is the country of truth (a very attractive name), but surrounded by a wide and stormy ocean, the true home of illusion, where many a fog bank and ice that soon melts away tempt us to believe in new lands, while constantly deceiving the adventurous mariner with vain hopes, and involving [p. 236] him in adventures which he can never leave, and yet can never bring to an end. Before we venture ourselves on this sea, in order to explore it on every side, and to find out whether anything is to be hoped for there, it will be useful to glance once more at the map of that country which we are about to leave, and to ask ourselves, first, whether we might not be content with what it contains, nay, whether we must not be content with it, supposing that there is no solid ground anywhere else on which we could settle; secondly, by what title we possess even that domain, and may consider ourselves safe against all hostile claims. Although we have sufficiently answered these questions in the course of the analytic, a summary recapitulation of their solutions may help to strengthen our conviction, by uniting all arguments in one point.

We have seen that the understanding possesses everything which it draws from itself, without borrowing from experience, for no other purpose but for experience. The principles of the pure understanding, whether constitutive a priori (as the mathematical) or simply relative (as the dynamical), contain nothing but, as it were, the pure schema of possible experience; for that experience [p. 237] derives its unity from that synthetical unity alone which the understanding originally and spontaneously imparts to the synthesis of imagination, with reference to apperception, and to which all phenomena, as data of a possible knowledge, must conform a priori. But although these rules of the understanding are not only true a priori, but the very source of all truth, that is, of the agreement of our knowledge with objects, because containing the conditions of the possibility of experience, as the complete sphere of all knowledge in which objects can be given to us, nevertheless we do not seem to be content with hearing only what is true, but want to know a great deal more. If therefore this critical investigation does not teach us any more than what, even without such subtle researches, we should have practised ourselves in the purely empirical use of the understanding, it would seem as if the advantages derived from it were hardly worth the labour. One might reply that nothing would be more prejudicial to the enlargement of our knowledge than that curiosity which, before entering upon any researches, wishes to know beforehand the advantages likely to accrue from them, though quite unable as yet to form the least conception of such advantages, even though they were placed before our eyes. There is, however, one advantage in this transcendental investigation which can be rendered intelligible, [p. 238] nay, even attractive to the most troublesome and reluctant apprentice, namely this, that the understanding confined to its empirical use only and unconcerned with regard to the sources of its own knowledge, may no doubt fare very well in other respects, but can never determine for itself the limits of its own use and know what is inside or outside its own sphere. It is for that purpose that such profound investigations are required as we have just instituted. If the understanding cannot decide whether certain questions lie within its own horizon or not, it can never feel certain with regard to its claims and possessions, but must be prepared for many humiliating corrections, when constantly transgressing, as it certainly will, the limits of its own domain, and losing itself in follies and fancies.

That the understanding cannot make any but an empirical, and never a transcendental, use of all its principles a priori, nay, of all its concepts, is a proposition which, if thoroughly understood, leads indeed to most important consequences. What we call the transcendental use of a concept in any proposition is its being referred to things in general and to things by themselves, while its empirical use refers to phenomena only, that is, to objects of a possible experience. That the latter use alone is admissible will be clear from the following considerations. [p. 239] What is required for every concept is, first, the logical form of a concept (of thought) in general; and, secondly, the possibility of an object to which it refers. Without the latter, it has no sense, and is entirely empty, though it may still contain the logical function by which a concept can be formed out of any data. The only way in which an object can be given to a concept is in intuition, and though a pure intuition is possible a priori and before the object, yet even that pure intuition can receive its object, and with it its objective validity, by an empirical intuition only, of which it is itself nothing but the form. All concepts, therefore, and with them all principles, though they may be possible a priori, refer nevertheless to empirical intuitions, that is, to data of a possible experience. Without this, they can claim no objective validity, but are a mere play, whether of the imagination or of the understanding with their respective representations. Let us take the concepts of mathematics as an example, and, first, with regard to pure intuitions. Although such principles as ‘space has three dimensions,’ ‘between two points there can be only one straight line,’ as well as the representation of the object with which that science is occupied, may be produced in the mind a priori, they would have no meaning, if we were not able at all times [p. 240] to show their meaning as applied to phenomena (empirical objects). It is for this reason that an abstract concept is required to be made sensuous, that is, that its corresponding object is required to be shown in intuition, because, without this, the concept (as people say) is without sense, that is, without meaning. Mathematics fulfil this requirement by the construction of the figure, which is a phenomenon present to the senses (although constructed a priori). In the same science the concept of quantity finds its support and sense in number; and this in turn in the fingers, the beads of the abacus, or in strokes and points which can be presented to the eyes. The concept itself was produced a priori, together with all the synthetical principles or formulas which can be derived from such concepts; but their use and their relation to objects can nowhere be found except in experience, of which those concepts contain a priori the (formal) possibility only.

That this is the case with all categories and with all the principles drawn from them, becomes evident from the fact that we could not define any one of them (really, that is, make conceivable the possibility of their object),1 without at once having recourse to the conditions of sensibility or the form of phenomena, to which, as their only possible objects, these categories must necessarily be restricted, it being impossible, if we take away [p. 241] these conditions, to assign to them any meaning, that is, any relation to an object, or to make it intelligible to ourselves by an example what kind of thing could be intended by such concepts.

[When representing the table of the categories, we dispensed with the definition of every one of them, because at that time it seemed unnecessary for our purpose, which concerned their synthetical use only, and because entailing responsibilities which we were not bound to incur. This was not a mere excuse, but a very important prudential rule, viz. not to rush into definitions, and to attempt or pretend completeness or precision in the definition of a concept, when one or other of its characteristic marks is sufficient without a complete enumeration of all that constitute the whole concept. Now, however, we can perceive that this caution had even a deeper ground, namely, that we could not have defined them, even if we had wished;1 for, if we remove all conditions of [p. 242] sensibility, which distinguish them as the concepts of a possible empirical use, and treat them as concepts of things in general (therefore as of transcendental use), nothing remains but to regard the logical function in judgments as the condition of the possibility of the things themselves, without the slightest indication as to where they could have their application and their object, or how they could have any meaning or objective validity in the pure understanding, apart from sensibility.]2

No one can explain the concept of quantity in general, except, it may be, by saying that it is the determination of an object, by which we may know how many times the one is supposed to exist in it. But this ‘how many times’ is based on successive repetition, that is on time, and on the synthesis in it of the homogeneous.

Reality, again, can only be explained in opposition to a negation, if we think of time (as containing all being) being either filled or empty.

Were I to leave out permanence (which means existence at all times), nothing would remain of my concept of substance but the logical representation of a subject which I think I can realise by imagining something which is a subject only, without [p. 243] being a predicate of anything. But in this case we should not only be ignorant of all conditions under which this logical distinction could belong to anything, but we should be unable to make any use of it or draw any conclusions from it, because no object is thus determined for the use of this concept, and no one can tell whether such a concept has any meaning at all.

Of the concept of cause also (if I leave out time, in which something follows on something else by rule) I should find no more in the pure category than that it is something which enables us to conclude the existence of something else, so that it would not only be impossible to distinguish cause and effect from each other, but the concept of cause would possess no indication as to how it can be applied to any object, because, in order to form any such conclusion, certain conditions require to be known of which the concept itself tells us nothing. The so-called principle that everything contingent has a cause, comes no doubt before us with great solemnity and self-assumed dignity. But, if I ask what you understand by contingent and you answer, something of which the non-existence is possible, I should be glad to know how you can recognise this possibility of non-existence, if you do not represent to yourselves, in the series of phenomena, some kind of succession, and in it an existence that follows upon non-existence (or vice versa), and consequently a change? To say that the non-existence of a thing is not self-contradictory [p. 244] is but a lame appeal to a logical condition which, though it is necessary for the concept, yet is by no means sufficient for its real possibility. I can perfectly well remove in thought every existing substance, without contradicting myself, but I can by no means conclude from this as to its objective contingency in its existence, that is, the possibility of its non-existence in itself.

As regards the concept of community, it is easy to see that, as the pure categories of substance and causality admit of no explanation that would determine their object, neither could such an explanation apply to the reciprocal causality in the relation of substances to each other (commercium).

As to possibility, existence, and necessity, no one has yet been able to explain them, except by a manifest tautology, so long as their definition is to be exclusively drawn from the pure understanding. To substitute the transcendental possibility of things (when an object corresponds to a concept) for the logical possibility of the concept (when the concept does not contradict itself) is a quibble such as could deceive and satisfy the inexperienced only.

[It seems to be something strange and even illogical1 that there should be a concept which must have a meaning, and yet is incapable of any explanation. But the case of these categories is peculiar, because it is only by means of the general sensuous condition that they can acquire a definite meaning, and a reference to any objects. That condition being [p. 245] left out in the pure category, it follows that it can contain nothing but the logical function by which the manifold is brought into a concept. By means of this function, that is, the pure form of the concept, nothing can be known nor distinguished as to the object belonging to it, because the sensuous condition, under which alone objects can belong to it, has been removed. Thus we see that the categories require, besides the pure concept of the understanding, certain determinations of their application to sensibility in general (schemata). Without them, they would not be concepts by which an object can be known and distinguished from other objects, but only so many ways of thinking an object for possible intuitions, and giving to it, according to one of the functions of the understanding, its meaning (certain requisite conditions being given). They are needed to define an object, and cannot therefore be defined themselves. The logical functions of judgments in general, namely, unity and plurality, assertion and negation, subject and predicate, cannot be defined without arguing in a circle, because the definition would itself be a judgment and contain these very functions. The pure categories are nothing but representations of things in general, so far as the manifold in intuition must be thought by one or the other of these functions. Thus, magnitude is the determination which can [only be thought by a judgment possessing [p. 246] quantity (judicium commune); reality, the determination which can only be thought by an affirmative judgment; while substance is that which, in regard to intuition, must be the last subject of all other determinations. With all this it remains perfectly undetermined, what kind of things they may be with regard to which we have to use one rather than another of these functions, so that, without the condition of sensuous intuition, for which they supply the synthesis, the categories have no relation to any definite object, cannot define any object, and consequently have not in themselves the validity of objective concepts.]

From this it follows incontestably, that the pure concepts of the understanding never admit of a transcendental, but only of an empirical use, and that the principles of the pure understanding can only be referred, as general conditions of a possible experience, to objects of the senses, never to things by themselves (without regard to the manner in which we have to look at them).

Transcendental Analytic has therefore yielded us this important result, that the understanding a priori can never do more than anticipate the form of a possible experience; and as nothing can be an object of experience except the phenomenon, it follows that the understanding can never go beyond the limits of sensibility, within which alone objects are given to us. Its principles are principles [p. 247] for the exhibition of phenomena only; and the proud name of Ontology, which presumes to supply in a systematic form different kinds of synthetical knowledge a priori of things by themselves (for instance the principle of causality), must be replaced by the more modest name of a mere Analytic of the pure understanding.

Thought is the act of referring a given intuition to an object. If the mode of such intuition is not given, the object is called transcendental, and the concept of the understanding admits then of a transcendental use only, in producing a unity in the thought of the manifold in general. A pure category therefore, in which every condition of sensuous intuition, the only one that is possible for us, is left out, cannot determine an object, but only the thought of an object in general, according to different modes. Now, if we want to use a concept, we require in addition some function of the faculty of judgment, by which an object is subsumed under a concept, consequently the at least formal condition under which something can be given in intuition. If this condition of the faculty of judgment (schema) is wanting, all subsumption is impossible, because nothing is given that could be subsumed under the concept. The purely transcendental use of categories therefore is in reality of no use at all, and has no definite or even, with regard to its form only, definable object. Hence it follows that a pure category is not fit for any [p. 248] synthetical a priori principle, and that the principles of the pure understanding admit of empirical only, never of transcendental application, nay, that no synthetical principles a priori are possible beyond the field of possible experience.

It might therefore be advisable to express ourselves in the following way: the pure categories, without the formal conditions of sensibility, have a transcendental character only, but do not admit of any transcendental use, because such use in itself is impossible, as the categories are deprived of all the conditions of being used in judgments, that is, of the formal conditions of the subsumption of any possible object under these concepts. As therefore (as pure categories) they are not meant to be used empirically, and cannot be used transcendentally, they admit, if separated from sensibility, of no use at all; that is, they cannot be applied to any possible object, and are nothing but the pure form of the use of the understanding with reference to objects in general, and of thought, without ever enabling us to think or determine any object by their means alone.

[Appearances,1 so far as they are thought as objects under the unity of the categories, are called phenomena. But if I admit things which are objects of the [p. 249] understanding only, and nevertheless can be given as objects of an intuition, though not of sensuous intuition (as coram intuitu intellectuali), such things would be called Noumena (intelligibilia).

One might feel inclined to think that the concept of Phenomena, as limited by the transcendental æsthetic, suggested by itself the objective reality of the Noumena, and justified a division of objects into phenomena and noumena, and consequently of the world into a sensible and intelligible world (mundus sensibilis et intelligibilis); and this in such a way that the distinction between the two should not refer to the logical form only of a more or less clear knowledge of one and the same object, but to a difference in their original presentation to our knowledge, which makes them to differ in themselves from each other in kind. For if the senses only represent to us something as it appears, that something must by itself also be a thing, and an object of a non-sensuous intuition, i.e. of the understanding. That is, there must be a kind of knowledge in which there is no sensibility, and which alone possesses absolute objective reality, representing objects as they are, while through the empirical use of our understanding we know things only as they appear. Hence it would seem to follow that, beside the empirical [p. 250] use of the categories (limited by sensuous conditions), there was another one, pure and yet objectively valid, and that we could not say, as we have hitherto done, that our knowledge of the pure understanding contained nothing but principles for the exhibition of phenomena, which, even a priori, could not apply to anything but the formal possibility of experience. Here, in fact, quite a new field would seem to be open, a world, as it were, realised in thought (nay, according to some, even in intuition), which would be a more, and not a less, worthy object for the pure understanding.

All our representations are no doubt referred by the understanding to some sort of object, and as phenomena are nothing but representations, the understanding refers them to a something, as the object of our sensuous intuition, this something being however the transcendental object only. This means a something equal to x, of which we do not, nay, with the present constitution of our understanding, cannot know anything, but which1 can only serve, as a correlatum of the unity of apperception, for the unity of the manifold in sensuous intuition, by means of which the understanding unites the manifold into the concept of an object. This transcendental object cannot be separated from the sensuous data, because in that case nothing would remain by which it could be [p. 251] thought. It is not therefore an object of knowledge in itself, but only the representation of phenomena, under the concept of an object in general, which can be defined by the manifold of sensuous intuition.

For this very reason the categories do not represent a peculiar object, given to the understanding only, but serve only to define the transcendental object (the concept of something in general) by that which is given us through the senses, in order thus to know empirically phenomena under the concepts of objects.

What then is the cause why people, not satisfied with the substratum of sensibility, have added to the phenomena the noumena, which the understanding only is supposed to be able to realise? It is this, that sensibility and its sphere, that is the sphere of phenomena, is so limited by the understanding itself that it should not refer to things by themselves, but only to the mode in which things appear to us, in accordance with our own subjective qualification. This was the result of the whole transcendental æsthetic, and it really follows quite naturally from the concept of a phenomenon in general, that something must correspond to it, which in itself is not a phenomenon, because a phenomenon cannot be anything by itself, apart from our mode of representation. [p. 252] Unless therefore we are to move in a constant circle, we must admit that the very word phenomenon indicates a relation to something the immediate representation of which is no doubt sensuous, but which nevertheless, even without this qualification of our sensibility (on which the form of our intuition is founded) must be something by itself, that is an object independent of our sensibility.

Hence arises the concept of a noumenon, which however is not positive, nor a definite knowledge of anything, but which implies only the thinking of something, without taking any account of the form of sensuous intuition. But in order that a noumenon may signify a real object that can be distinguished from all phenomena, it is not enough that I should free my thought of all conditions of sensuous intuition, but I must besides have some reason for admitting another kind of intuition besides the sensuous, in which such an object can be given; otherwise my thought would be empty, however free it may be from contradictions. It is true that we were not able to prove that the sensuous is the only possible intuition, though it is so for us: but neither could we prove that another kind of intuition was possible; and although our thought may take no account of any sensibility, the question always remains whether, after that, it is not a mere [p. 253] form of a concept, and whether any real object would thus be left.

The object to which I refer the phenomenon in general is the transcendental object, that is, the entirely indefinite thought of something in general. This cannot be called the noumenon, for I know nothing of what it is by itself, and have no conception of it, except as the object of sensuous intuition in general, which is therefore the same for all phenomena. I cannot lay hold of it by any of the categories, for these are valid for empirical intuitions only, in order to bring them under the concept of an object in general. A pure use of the categories is no doubt possible, that is, not self-contradictory, but it has no kind of objective validity, because it refers to no intuition to which it is meant to impart the unity of an object. The categories remain for ever mere functions of thought by which no object can be given to me, but by which I can only think whatever may be given to me in intuition.]

If all thought (by means of categories) is taken away from empirical knowledge, no knowledge of any object remains, because nothing can be thought by mere intuition, and the mere fact that there is within me an affection of my sensibility, establishes in no way any relation of such a representation to any object. If, on the contrary, all intuition is taken away, there always remains [p. 254] the form of thought, that is, the mode of determining an object for the manifold of a possible intuition. In this sense the categories may be said to extend further than sensuous intuition, because they can think objects in general without any regard to the special mode of sensibility in which they may be given; but they do not thus prove a larger sphere of objects, because we cannot admit that such objects can be given, without admitting the possibility of some other but sensuous intuition, for which we have no right whatever.

I call a concept problematic, if it is not self-contradictory, and if, as limiting other concepts, it is connected with other kinds of knowledge, while its objective reality cannot be known in any way. Now the concept of a noumenon, that is of a thing which can never be thought as an object of the senses, but only as a thing by itself (by the pure understanding), is not self-contradictory, because we cannot maintain that sensibility is the only form of intuition. That concept is also necessary, to prevent sensuous intuition from extending to things by themselves; that is, in order to limit the objective validity of sensuous knowledge (for all the rest to which sensuous intuition does not extend is called noumenon, for [p. 255] the very purpose of showing that sensuous knowledge cannot extend its domain over everything that can be thought by the understanding). But, after all, we cannot understand the possibility of such noumena, and whatever lies beyond the sphere of phenomena is (to us) empty; that is, we have an understanding which problematically extends beyond that sphere, but no intuition, nay not even the conception of a possible intuition, by which, outside the field of sensibility, objects could be given to us, and our understanding could extend beyond that sensibility in its assertory use. The concept of a noumenon is therefore merely limitative, and intended to keep the claims of sensibility within proper bounds, therefore of negative use only. But it is not a mere arbitrary fiction, but closely connected with the limitation of sensibility, though incapable of adding anything positive to the sphere of the senses.

A real division of objects into phenomena and noumena, and of the world into a sensible and intelligible world (in a positive sense),1 is therefore quite inadmissible, although concepts may very well be divided into sensuous and intellectual. For no objects can be assigned to these intellectual concepts, nor can they be represented as objectively valid. If we drop the senses, how are we to make it [p. 256] conceivable that our categories (which would be the only remaining concepts for noumena) have any meaning at all, considering that, in order to refer them to any object, something more must be given than the mere unity of thought, namely, a possible intuition, to which the categories could be applied? With all this the concept of a noumenon, if taken as problematical only, remains not only admissible, but, as a concept to limit the sphere of sensibility, indispensable. In this case, however, it is not a particular intelligible object for our understanding, but an understanding to which it could belong is itself a problem, if we ask how it could know an object, not discursively by means of categories, but intuitively, and yet in a nonsensuous intuition, — a process of which we could not understand even the bare possibility. Our understanding thus acquires a kind of negative extension, that is, it does not become itself limited by sensibility, but, on the contrary, limits it, by calling things by themselves (not considered as phenomena) noumena. In doing this, it immediately proceeds to prescribe limits to itself, by admitting that it cannot know these noumena by means of the categories, but can only think of them under the name of something unknown.

In the writings of modern philosophers, however, I meet with a totally different use of the terms of mundus sensibilis and intelligibilis,1 totally different from the meaning assigned to these terms by the ancients. [p. 257] Here all difficulty seems to disappear. But the fact is, that there remains nothing but mere word-mongery. In accordance with this, some people have been pleased to call the whole of phenomena, so far as they are seen, the world of sense; but so far as their connection, according to general laws of the understanding, is taken into account, the world of the understanding. Theoretical astronomy, which only teaches the actual observation of the starry heavens, would represent the former; contemplative astronomy, on the contrary (taught according to the Copernican system, or, it may be, according to Newton’s laws of gravitation), the latter, namely, a purely intelligible world. But this twisting of words is a mere sophistical excuse, in order to avoid a troublesome question, by changing its meaning according to one’s own convenience. Understanding and reason may be applied to phenomena, but it is very questionable whether they can be applied at all to an object which is not a phenomenon, but a noumenon; and it is this, when the object is represented as purely intelligible, that is, as given to the understanding only, and not to the senses. The question therefore is whether, besides the empirical use of the understanding (even in the Newtonian view of the world), a transcendental use is possible, referring to the noumenon, as its object; and that question we have answered decidedly in the negative.

When we therefore say that the senses represent [p. 258] objects to us as they appear, and the understanding as they are, the latter is not to be taken in a transcendental, but in a purely empirical meaning, namely, as to how they, as objects of experience, must be represented, according to the regular connection of phenomena, and not according to what they may be, as objects of the pure understanding, apart from their relation to possible experience, and therefore to our senses. This will always remain unknown to us; nay, we shall never know whether such a transcendental and exceptional knowledge is possible at all, at least as comprehended under our ordinary categories. With us understanding and sensibility cannot determine objects, unless they are joined together. If we separate them, we have intuitions without concepts, or concepts without intuitions, in both cases representations which we cannot refer to any definite object.

If, after all these arguments, anybody should still hesitate to abandon the purely transcendental use of the categories, let him try an experiment with them for framing any synthetical proposition. An analytical proposition does not in the least advance the understanding, which, as in such a proposition it is only concerned with what is already thought in the concept, does not ask whether the concept in itself has any reference to objects, or expresses only the unity of thought in general [p. 259] (this completely ignoring the manner in which an object may be given). The understanding in fact is satisfied if it knows what it contained in the concept of an object; it is indifferent as to the object to which the concept may refer. But let him try the experiment with any synthetical and so-called transcendental proposition, as for instance, ‘Everything that exists, exists as a substance, or as a determination inherent in it,’ or ‘Everything contingent exists as an effect of some other thing, namely, its cause,’ etc. Now I ask, whence can the understanding take these synthetical propositions, as the concepts are to apply, not to some possible experience, but to things by themselves (noumena)? Where is that third term to be found which is always required for a synthetical proposition, in order thus to join concepts which have no logical (analytical) relation with each other? It will be impossible to prove such a proposition, nay even to justify the possibility of any such pure assertion, without appealing to the empirical use of the understanding, and thus renouncing entirely the so-called pure and nonsensuous judgment. There are no principles therefore according to which the concepts of pure and merely intelligible objects could ever be applied, because we cannot imagine any way in which they could be given, and the problematic thought, which leaves a place open to them, serves only, like empty space, to limit the sphere of empirical principles, without containing or indicating [p. 260] any other object of knowledge, lying beyond that sphere.

APPENDIX

Of the Amphiboly of Reflective Concepts, owing to the Confusion of the Empirical with the Transcendental Use of the Understanding

Reflection (reflexio) is not concerned with objects themselves, in order to obtain directly concepts of them, but is a state of the mind in which we set ourselves to discover the subjective conditions under which we may arrive at concepts. It is the consciousness of the relation of given representations to the various sources of our knowledge by which alone their mutual relation can be rightly determined. Before saying any more of our representations, the first question is, to which faculty of knowledge they may all belong; whether it is the understanding or the senses by which they are connected and compared. Many a judgment is accepted from mere habit, or made from inclination, and as no reflection precedes or even follows it critically, the judgment is supposed [p. 261] to have had its origin in the understanding. It is not all judgments that require an investigation, that is, a careful attention with regard to the grounds of their truth; for if they are immediately certain, as for instance, that between two points there can be only one straight line, no more immediately certain marks of their truth than that which they themselves convey could be discovered. But all judgments, nay, all comparisons, require reflection, that is, a discrimination of the respective faculty of knowledge to which any given concepts belong. The act by which I place in general the comparison of representations by the side of the faculty of knowledge to which that comparison belongs, and by which I determine whether these representations are compared with each other as belonging to the pure understanding or to sensuous intuition, I call transcendental reflection. The relation in which the two concepts may stand to each other in one state of the mind is that of identity and difference, of agreement and opposition, of the internal and external, and finally of the determinable and the determination (matter and form). The right determination of that relation depends on the question in which faculty of knowledge they subjectively belong to each other, whether in sensibility or in the understanding. For the proper distinction of the latter is of great importance with regard to the manner in which the former must be considered. [p. 262]

Before proceeding to form any objective judgments, we have to compare the concepts with regard to the identity (of many representations under one concept) as the foundation of general judgments, or with regard to their difference as the foundation of particular judgments, or with regard to their agreement and opposition serving as the foundations of affirmative and negative judgments, etc. For this reason it might seem that we ought to call these concepts concepts of comparison (conceptus comparationis). But as, when the contents of concepts and not their logical form must be considered, that is, whether the things themselves are identical or different, in agreement or in opposition, etc., all things may have a twofold relation to our faculty of knowledge, namely, either to sensibility or to the understanding, and as the manner in which they belong to one another depends on the place to which they belong, it follows that the transcendental reflection, that is the power of determining the relation of given representations to one or the other class of knowledge, can alone determine their mutual relation. Whether the things are identical or different, in agreement or opposition, etc., cannot be established at once by the concepts themselves by means of a mere comparison (comparatio), but first of all by a proper discrimination of that class of knowledge to which they belong, that is, by transcendental reflection. It might therefore be said, that logical reflection is a mere comparison, because it takes no account of the faculty of knowledge to which any given representations belong, and treats [p. 263] them, so far as they are all found in the mind, as homogeneous, while transcendental reflection (which refers to the objects themselves) supplies the possibility of an objective comparison of representations among themselves, and is therefore very different from the other, the faculty of knowledge to which they belong not being the same. This transcendental reflection is a duty from which no one can escape who wishes to form judgments a priori. We shall now take it in hand, and may hope thus to throw not a little light on the real business of the understanding.

I.

Identity and Difference

When an object is presented to us several times, but each time with the same internal determinations (qualitas et quantitas), it is, so long as it is considered as an object of the pure understanding, always one and the same, one thing, not many (numerica identitas). But if it is a phenomenon, a comparison of the concepts is of no consequence, and though everything may be identical with regard to the concepts, yet the difference of the places of this phenomenon at the same time is a sufficient ground for admitting the numerical difference of the object (of the senses). Thus, though there may be no internal difference whatever (either in quality or quantity) between two drops of water, yet the fact that they may be seen [p. 264] at the same time in different places is sufficient to establish their numerical difference. Leibniz took phenomena to be things by themselves, intelligibilia, that is, objects of the pure understanding (though, on account of the confused nature of their representations, he assigned to them the name of phenomena), and from that point of view his principle of their indiscernibility (principium identitas indiscernibilium) could not be contested. As, however, they are objects of sensibility, and the use of the understanding with regard to them is not pure, but only empirical, their plurality and numerical diversity are indicated by space itself, as the condition of external phenomena. For one part of space, though it may be perfectly similar and equal to another, is still outside it, and for this very reason a part of space different from the first which, added to it, makes a larger space: and this applies to all things which exist at the same time in different parts of space, however similar or equal they may be in other respects.

II.

Agreement and Opposition

When reality is represented by the pure understanding only (realitas noumenon), no opposition can be conceived between realities, that is, no such relation that, if connected in one subject, they should annihilate the effects one of the other, as for instance 3 - 3 = 0. The real in [p. 265] the phenomena, on the contrary (realitas phenomenon), may very well be in mutual opposition, and if connected in one subject, one may annihilate completely or in part the effect of the other, as in the case of two forces moving in the same straight line, either drawing or impelling a point in opposite directions, or in the case of pleasure, counterbalancing a certain amount of pain.

III.

The Internal and the External

In an object of the pure understanding that only is internal which has no relation whatever (as regards its existence) to anything different from itself. The inner relations, on the contrary, of a substantia phenomenon in space are nothing but relations, and the substance itself a complex of mere relations. We only know substances in space through the forces which are active in a certain space, by either drawing others near to it (attraction) or by preventing others from penetrating into it (repulsion and impenetrability). Other properties constituting the concept of a substance appearing in space, and which we call matter, are unknown to us. As an object of the pure understanding, on the contrary, every substance must have internal determinations and forces bearing on the internal reality. But what other internal accidents can I think except those which my own internal sense presents [p. 266] to me, namely, something which is either itself thought, or something analogous to it? Hence Leibniz represented all substances (as he conceived them as noumena), even the component parts of matter (after having in thought removed from them everything implying external relation, and therefore composition also), as simple subjects endowed with powers of representation, in one word, as monads.

IV.

Matter and Form

These are two concepts which are treated as the foundation of all other reflection, so inseparably are they connected with every act of the understanding. The former denotes the determinable in general, the latter its determination (both in a purely transcendental meaning, all differences in that which is given and the mode in which it is determined being left out of consideration). Logicians formerly called the universal, matter; the specific difference, form. In every judgment the given concepts may be called the logical matter (for a judgment); their relation, by means of the copula, the form of a judgment. In every being its component parts (essentialia) are the matter; the mode in which they are connected in it, the essential form. With respect to things in general, unlimited reality was regarded as the matter of all possibility, and the limitation thereof (negation) as that form by which one [p. 267] thing is distinguished from another, according to transcendental concepts. The understanding demands first that something should be given (at least in concept) in order to be able afterwards to determine it in a certain manner. In the concept of the pure understanding therefore, matter comes before form, and Leibniz in consequence first assumed things (monads), and within them an internal power of representation, in order afterwards to found thereon their external relation, and the community of their states, that is, of their representations. In this way space and time were possible only, the former through the relation of substances, the latter through the connection of their determinations among themselves, as causes and effects. And so it would be indeed, if the pure understanding could be applied immediately to objects, and if space and time were determinations of things by themselves. But if they are sensuous intuitions only, in which we determine all objects merely as phenomena, then it follows that the form of intuition (as a subjective quality of sensibility) comes before all matter (sensations), that space and time therefore come before all phenomena, and before all data of experience, and render in fact all experience possible. As an intellectual philosopher Leibniz could not endure that this form should come before things and determine their possibility: a criticism quite just when he assumed that we see things as they are (though in a confused representation). But as sensuous intuition is a peculiar [p. 268] subjective condition on which all perception a priori depends, and the form of which is original and independent, the form must be given by itself, and so far from matter (or the things themselves which appear) forming the true foundation (as we might think, if we judged according to mere concepts), the very possibility of matter presupposes a formal intuition (space and time) as given.

NOTE ON THE AMPHIBOLY OF REFLECTIVE CONCEPTS

I beg to be allowed to call the place which we assign to a concept, either in sensibility or in the pure understanding, its transcendental place. If so, then the determination of this position which belongs to every concept, according to the difference of its use, and the directions for determining according to rules that place for all concepts, would be called transcendental topic; a doctrine which would thoroughly protect us against the subreptitious claims of the pure understanding and the errors arising from it, by always distinguishing to what faculty of knowledge each concept truly belongs. Every concept, or every title to which many kinds of knowledge belong, may be called a logical place. Upon this is based the logical topic of Aristotle, of which orators and schoolmasters avail themselves in order to find under certain titles of thought [p. 269] what would best suit the matter they have in hand, and thus to be able, with a certain appearance of thoroughness, to argue and wrangle to any extent.

Transcendental topic, on the contrary, contains no more than the above-mentioned four titles of all comparison and distinction, which differ from the categories because they do not serve to represent the object according to what constitutes its concept (quantity, reality, etc.), but only the comparison of representations, in all its variety, which precedes the concept of things. This comparison, however, requires first a reflection, that is, a determination of the place to which the representations of things which are to be compared belong, namely, whether they are thought by the pure understanding or given as phenomena by sensibility.

Concepts may be logically compared without our asking any questions as to what place their objects belong, whether as noumena to the understanding, or to sensibility as phenomena. But if with these concepts we wish to proceed to the objects themselves, a transcendental reflection is necessary first of all, in order to determine whether they are meant to be objects for the pure understanding or for sensibility. Without this reflection our use of these concepts would be very uncertain, and [p. 270] synthetical propositions would spring up which critical reason cannot acknowledge, and which are simply founded on transcendental amphiboly, that is, on our confounding an object of the pure understanding with a phenomenon.

For want of such a transcendental topic, and deceived by the amphiboly of reflective concepts, the celebrated Leibniz erected an intellectual system of the world, or believed at least that he knew the internal nature of things by comparing all objects with the understanding only and with the abstract formal concepts of his thought. Our table of reflective concepts gives us the unexpected advantage of being able to exhibit clearly the distinctive features of his system in all its parts, and at the same time the leading principle of this peculiar view which rested on a simple misunderstanding. He compared all things with each other by means of concepts only, and naturally found no other differences but those by which the understanding distinguishes its pure concepts from each other. The conditions of sensuous intuition, which carry their own differences, are not considered by him as original and independent; for sensibility was with him a confused mode of representation only, and not a separate source of representations. According to him a phenomenon was the representation of a thing by itself, though different, in its logical form, from knowledge by means of the [p. 271] understanding, because the phenomenon, in the ordinary absence of analysis, brings a certain admixture of collateral representations into the concept of a thing which the understanding is able to separate. In one word, Leibniz intellectualised phenomena, just as Locke, according to his system of Noogony (if I may use such an expression), sensualised all concepts of the understanding, that is, represented them as nothing but empirical, though abstract, reflective concepts. Instead of regarding the understanding and sensibility as two totally distinct sources of representations, which however can supply objectively valid judgments of things only in conjunction with each other, each of these great men recognised but one of them, which in their opinion applied immediately to things by themselves, while the other did nothing but to produce either disorder or order in the representations of the former.

Leibniz accordingly compared the objects of the senses with each other as things in general and in the understanding only. He did this,

First, so far as they are judged by the understanding to be either identical or different. As he considers their concepts only and not their place in intuition, in which alone objects can be given, and takes no account of the transcendental place of these concepts (whether the object is to be counted among phenomena or among things by themselves), it could not happen otherwise than [p. 272] that he should extend his principle of indiscernibility, which is valid with regard to concepts of things in general only, to objects of the senses also (mundus phaenomenon), and imagine that he thus added no inconsiderable extension to our knowledge of nature. No doubt, if I know a drop of water as a thing by itself in all its internal determinations, I cannot allow that one is different from the other, when their whole concepts are identical. But if the drop of water is a phenomenon in space, it has its place not only in the understanding (among concepts), but in the sensuous external intuition (in space), and in this case the physical place is quite indifferent with regard to the inner determinations of things, so that a place B can receive a thing which is perfectly similar or identical with another in place A, quite as well as if it were totally different from it in its internal determinations. Difference of place by itself and without any further conditions renders the plurality and distinction of objects as phenomena not only possible, but also necessary. That so-called law of Leibniz therefore is no law of nature, but only an analytical rule, or a comparison of things by means of concepts only.

Thirdly. The Leibnizian monadology has really no other foundation than that Leibniz represented the difference of the internal and the external in relation to the understanding only. Substances must have something internal, which is free from all external relations, and therefore from composition also. The simple, therefore, or uncompounded, is the foundation of the internal of things by themselves. This internal in the state of substances cannot consist in space, form, contact, or motion (all these determinations being external relations), and we cannot therefore ascribe to substances any other internal state but that which belongs to our own internal sense, namely, the state of representations. This is the history of the monads, which were to form the elements of the whole universe, and the energy of which consists in representations only, so that properly they can be active within themselves only.

For this reason, his principle of a possible community of substances could only be a pre-established harmony, and not a physical influence. For, as everything [p. 275] is actively occupied internally only, that is, with its own representations, the state of representations in one substance could not be in active connection with that of another; but it became necessary to admit a third cause, exercising its influence on all substances, and making their states to correspond with each other, not indeed by occasional assistance rendered in each particular case (systema assistentiae), but through the unity of the idea of a cause valid for all, and in which all together must receive their existence and permanence, and therefore also their reciprocal correspondence according to universal laws.

Fourthly. Leibniz’s celebrated doctrine of space and time, in which he intellectualised these forms of sensibility, arose entirely from the same delusion of transcendental reflection. If by means of the pure understanding alone I want to represent the external relations of things, I can do this only by means of the concept of their reciprocal action; and if I want to connect one state with another state of the same thing, this is possible only in the order of cause and effect. Thus it happened that Leibniz conceived space as a certain order in the community of substances, and time as the dynamical sequence of their states. That which space and time seem to possess as proper to themselves and independent [p. 276] of things, he ascribed to the confusion of these concepts. which made us mistake what is a mere form of dynamical relations for a peculiar and independent intuition, antecedent to things themselves. Thus space and time became with him the intelligible form of the connection of things (substances and their states) by themselves, and things were intelligible substances (substantiae noumena). Nevertheless he tried to make these concepts valid for phenomena, because he would not concede to sensibility any independent kind of intuition, but ascribed all, even the empirical representation of objects, to the understanding, leaving to the senses nothing but the contemptible work of confusing and mutilating the representations of the understanding.

But, even if we could predicate anything synthetically by means of the pure understanding of things by themselves (which however is simply impossible), this could never be referred to phenomena, because these do not represent things by themselves. We should therefore in such a case have to compare our concepts in a transcendental reflection under the conditions of sensibility only, and thus space and time would never be determinations of things by themselves, but of phenomena. What things may be by themselves we know not, nor need [p. 277] we care to know, because, after all, a thing can never come before me otherwise than as a phenomenon.

The remaining reflective conceptions have to be treated in the same manner. Matter is substantia phenomenon. What may belong to it internally, I seek for in all parts of space occupied by it, and in all effects produced by it, all of which, however, can be phenomena of the external senses only. I have therefore nothing that is absolutely, but only what is relatively internal, and this consists itself of external relations. Nay, what according to the pure understanding should be the absolutely internal of matter is a mere phantom, for matter is never an object of the pure understanding, while the transcendental object which may be the ground of the phenomenon which we call matter, is a mere something of which we could not even understand what it is, though somebody should tell us. We cannot understand anything except what carries with it in intuition something corresponding to our words. If the complaint ‘that we do not understand the internal of things,’ means that we do not comprehend by means of the pure understanding what the things which appear to us may be of themselves, it seems totally unjust and unreasonable; for it means that without senses we should be able to know and therefore to see things, that is, that we should possess a faculty of knowledge totally different from the human, not only in degree, but in kind [p. 278] and in intuition, in fact, that we should not be men, but beings of whom we ourselves could not say whether they are even possible, much less what they would be like. Observation and analysis of phenomena enter into the internal of nature, and no one can say how far this may go in time. Those transcendental questions, however, which go beyond nature, would nevertheless remain unanswerable, even if the whole of nature were revealed to us, for it is not given to us to observe even our own mind with any intuition but that of our internal sense. In it lies the mystery of the origin of our sensibility. Its relation to an object, and the transcendental ground of that unity, are no doubt far too deeply hidden for us, who can know even ourselves by means of the internal sense only, that is, as phenomena, and we shall never be able to use the same imperfect instrument of investigation in order to find anything but again and again phenomena, the non-sensuous, and non-phenomenal cause of which we are seeking in vain.

What renders this criticism of the conclusions by means of the acts of mere reflection extremely useful is, that it shows clearly the nullity of all conclusions with regard to objects compared with each other in the understanding only, and that it confirms at the same time what [p. 279] we have so strongly insisted on, namely, that phenomena, though they cannot be comprehended as things by themselves among the objects of the pure understanding, are nevertheless the only objects in which our knowledge can possess objective reality, i.e. where intuition corresponds to concepts.

When we reflect logically only, we only compare in our understanding concepts among themselves, trying to find out whether both have exactly the same contents, whether they contradict themselves or not, whether something belongs to a concept, or is added to it, and which of the two may be given, while the other may be a mode only of thinking the given concept. But if I refer these concepts to an object in general (in a transcendental sense), without determining whether it be an object of sensuous or intellectual intuition, certain limitations appear at once, warning us not to go beyond the concept, and upsetting all empirical use of it, thus proving that a representation of an object, as of a thing in general, is not only insufficient, but, if without sensuous determination, and independent of empirical conditions, self-contradictory. It is necessary therefore either to take no account at all of the object (as we do in logic) or, if not, then to think it under the conditions of sensuous intuition, because the intelligible would require a quite peculiar intuition which we do not possess, and, without it, would be nothing to us, while on the other side phenomena also could never [p. 280] be things by themselves. For if I represent to myself things in general only, the difference of external relations cannot, it is true, constitute a difference of the things themselves, but rather presupposes it; and, if the concept of one thing does not differ at all internally from that of another, I only have one and the same thing placed in different relations. Furthermore, by adding a mere affirmation (reality) to another, the positive in it is indeed augmented, and nothing is taken away or removed, so that we see that the real in things can never be in contradiction with itself, etc.

*     *     *     *     *     *     *     *

A certain misunderstanding of these reflective concepts has, as we showed, exercised so great an influence on the use of the understanding, as to mislead even one of the most acute philosophers to the adoption of a so-called system of intellectual knowledge, which undertakes to determine objects without the intervention of the senses. For this reason the exposition of the cause of the misunderstanding, which lies in the amphiboly of these concepts, as the origin of false principles, is of great utility in determining and securing the true limits of the understanding.

It is no doubt true, that what can be affirmed or denied of a concept in general, can also be affirmed or denied of any part of it (dictum de omni et nullo); but it [p. 281] would be wrong so to change this logical proposition as to make it say that whatever is not contained in a general concept, is not contained either in the particular concepts comprehended under it; for these are particular concepts for the very reason that they contain more than is conceived in the general concept. Nevertheless the whole intellectual system of Leibniz is built up on this fallacy, and with it falls necessarily to the ground, together with all equivocation in the use of the understanding, that had its origin in it.

Leibniz’s principle of discernibility is really based on the supposition that, if a certain distinction is not to be found in the general concept of a thing, it could not be met with either in the things themselves, and that therefore all things were perfectly the same (numero eadem), which are not distinguished from each other in their concept also, as to quality or quantity. And because in the mere concept of a thing, no account has been taken of many a necessary condition of its intuition, it has rashly been concluded that that which, in forming an abstraction, has been intentionally left out of account, did really not exist anywhere, and nothing has been allowed to a thing except what is contained in its concept. [p. 282]

If by purely intelligible objects we understand things which, without all schemata of sensibility, are thought by mere categories, such objects are simply impossible. It is our sensuous intuition by which objects are given to us that forms the condition of the objective application of all the concepts of our understanding, and without that intuition the categories have no relation whatever to any object. Nay, even if we admitted a kind of intuition different from the sensuous, our functions of thought would have no meaning with regard to it. If we only mean objects of a non-sensuous intuition, to which our categories do not apply, and of which we can have no knowledge whatever (either intuitional or conceptual), there is no reason why noumena, in this merely negative meaning, should not be admitted, because in this case we mean no more than this, that our intuition does not embrace all things, but objects of our senses only; that, consequently, its objective validity is limited, and space left for some other kind of intuition, and consequently for things as objects of it. But in that sense the concept of a noumenon is problematical, that is, the representation of a thing of which we can neither say that it is possible or that it is impossible, because we have no conception of any kind of intuition but that of our senses, or of any kind of concepts but of our categories, [p. 287] neither of them being applicable to any extra-sensuous object. We cannot therefore extend in a positive sense the field of the objects of our thought beyond the conditions of our sensibility, or admit, besides phenomena, objects of pure thought, that is, noumena, simply because they do not possess any positive meaning that could be pointed out. For it must be admitted that the categories by themselves are not sufficient for a knowledge of things, and that, without the data of sensibility, they would be nothing but subjective forms of unity of the understanding, and without an object. We do not say that thought is a mere product of the senses, and therefore limited by them, but it does not follow that therefore thought, without sensibility, has its own pure use, because it would really be without an object. Nor would it be right to call the noumenon such an object of the pure understanding, for the noumenon means the problematical concept of an object, intended for an intuition and understanding totally different from our own, and therefore themselves mere problems. The concept of the noumenon is not therefore the concept of an object, but only a problem, inseparable from the limitation of our sensibility, whether there may not be objects independent of its intuition. This is a question that [p. 288] can only be answered in an uncertain way, by saying that as sensuous intuition does not embrace all things without exception, there remains a place for other objects, that cannot therefore be absolutely denied, but cannot be asserted either as objects of our understanding, because there is no definite concept for them (our categories being unfit for that purpose).

The understanding therefore limits the sensibility without enlarging thereby its own field, and by warning the latter that it can never apply to things by themselves, but to phenomena only, it forms the thought of an object by itself, but as transcendental only, which is the cause of phenomena, and therefore never itself a phenomenon: which cannot be thought as quantity, nor as reality, nor as substance (because these concepts require sensuous forms in which to determine an object), and of which therefore it must always remain unknown, whether it is to be found within us only, or also without us; and whether, if sensibility were removed, it would vanish or remain. If we like to call this object noumenon, because the representation of it is not sensuous, we are at liberty to do so. But as we cannot apply to it any of the concepts of our understanding, such a representation remains to us empty, serving no purpose but that of indicating the limits of our sensuous knowledge, and leaving at the same time an [p. 289] empty space which we cannot fill either by possible experience, or by the pure understanding.

The critique of the pure understanding does not therefore allow us to create a new sphere of objects beyond those which can come before it as phenomena, or to stray into intelligible worlds, or even into the concept of such. The mistake which leads to this in the most plausible manner, and which, though excusable, can never be justified, consists in making the use of the understanding, contrary to its very intention, transcendental, so that objects, that is, possible intuitions, are made to conform to concepts, not concepts to possible intuitions, on which alone their objective validity can rest. The cause of this is again, that apperception, and with it thought, precedes every possible determinate arrangement of representations. We are thinking something in general, and determine it on one side sensuously, but distinguish at the same time the general object, represented in abstraction, from this particular mode of sensuous intuition. Thus there remains to us a mode of determining the object by thought only, which, though it is a mere logical form without any contents, seems to us nevertheless a mode in which the object by itself exists (noumenon), without regard to the intuition which is restricted to our senses. [p. 290]

*     *     *     *     *     *     *     *

Before leaving this transcendental Analytic, we have to add something which, though in itself of no particular importance, may yet seem to be requisite for the completeness of the system. The highest concept of which all transcendental philosophy generally begins, is the division into the possible and the impossible. But, as all division presupposes a divisible concept, a higher concept is required, and this is the concept of an object in general, taken as problematical, it being left uncertain whether it be something or nothing. As the categories are the only concepts which apply to objects in general, the distinction whether an object is something or nothing must proceed according to the order and direction of the categories.

I. Opposed to the concepts of all, many, and one, is the concept which annihilates everything, that is, none; and thus the object of a concept, to which no intuition can be found to correspond, is = 0, that is, a concept without an object, like the noumena, which cannot be counted as possibilities, though not as impossibilities either (ens nationis); or like certain fundamental forces, [p. 291] which have been newly invented, and have been conceived without contradiction, but at the same time without any example from experience, and must not therefore be counted among possibilities.

II. Reality is something, negation is nothing; that is, it is the concept of the absence of an object, as shadow or cold (nihil privativum).

III. The mere form of intuition (without substance) is in itself no object, but the merely formal condition of it (as a phenomenon), as pure space and pure time (ens imaginarium), which, though they are something, as forms of intuition, are not themselves objects of intuition.

IV. The object of a concept which contradicts itself, is nothing, because the concept is nothing; it is simply the impossible, as a figure composed of two straight lines (nihil negativum).

A table showing this division of the concept of nothing (the corresponding division of the concept of something follows by itself) would have to be arranged as follows.

We see that the ens rationis (No. 1) differs from the ens negativum (No. 4), because the former cannot be counted among the possibilities, being the result of fancy, though not self-contradictory, while the latter is opposed to possibility, the concept annihilating itself. Both, however, are empty concepts. The nihil privativum (No. 2) and the ens imaginarium (No. 3) are, on the contrary, empty data for concepts. It would be impossible to represent to ourselves darkness, unless light had been given to the senses, or space, unless extended beings had been perceived. The negation, as well as the pure form of intuition are, without something real, no objects.

Division II

Transcendental Dialectic in two books, with their chapters and sections [p. 293]

INTRODUCTION

1.

Of Transcendental Appearance (Illusion)

We call Dialectic in general a logic of illusion (eine Logik des Scheins). This does not mean that it is a doctrine of probability (Wahrscheinlichkeit), for probability is a kind of truth, known through insufficient causes, the knowledge of which is therefore deficient, but not deceitful, and cannot properly be separated from the analytical part of logic. Still less can phenomenon (Erscheinung) and illusion (Schein) be taken as identical. For truth or illusion is not to be found in the objects of intuition, but in the judgments upon them, so far as they are thought. It is therefore quite right to say, that the senses never err, not because they always judge rightly, but because they do not judge at all. Truth therefore and error, and consequently illusory appearance also, as the cause of error, exist in our judgments only, that is, in the relation of an object to our understanding. No error exists in our knowledge, if it completely agrees with the laws of our understanding, nor can there be [p. 294] an error in a representation of the senses, because they involve no judgment, and no power of nature can, of its own accord, deviate from its own laws. Therefore neither the understanding by itself (without the influence of another cause), nor the senses by themselves could ever err. The understanding could not err, because as long as it acts according to its own laws, the effect (the judgment) must necessarily agree with those laws, and the formal test of all truth consists in this agreement with the laws of the understanding. The senses cannot err, because there is in them no judgment at all, whether true or false. Now as we have no other sources of knowledge but these two, it follows that error can only arise through the unperceived influence of the sensibility on the understanding, whereby it happens that subjective grounds of judgment are mixed up with the objective, and cause them to deviate from their destination;1 just as a body in motion would, if left to itself, always follow a straight line in the same direction, which is changed however into a curvilinear motion, as soon as another force influences it at the same time in a different direction. In order to distinguish the proper action [p. 295] of the understanding from that other force which is mixed up with it, it will be necessary to look on an erroneous judgment as the diagonal between two forces, which determine the judgment in two different directions, forming as it were an angle, and to dissolve that composite effect into the simple ones of the understanding and of the sensibility, which must be effected in pure judgments a priori by transcendental reflection, whereby, as we tried to show, the right place is assigned to each representation in the faculty of knowledge corresponding to it, and the influence of either faculty upon such representation is determined.

It is not at present our business to treat of empirical, for instance, optical appearance or illusion, which occurs in the empirical use of the otherwise correct rules of the understanding, and by which, owing to the influence of imagination, the faculty of judgment is misled. We have to deal here with nothing but the transcendental illusion, which touches principles never even intended to be applied to experience, which might give us a test of their correctness, — an illusion which, in spite of all the warnings of criticism, tempts us far beyond the empirical use of the categories, and deludes us with the mere dream of an extension of the pure understanding. All principles the application of which is entirely confined within the limits of possible experience, we [p. 296] shall call immanent; those, on the contrary, which tend to transgress those limits, transcendent. I do not mean by this the transcendental use or abuse of the categories, which is a mere fault of the faculty of the judgment, not being as yet sufficiently subdued by criticism nor sufficiently attentive to the limits of the sphere within which alone the pure understanding has full play, but real principles which call upon us to break down all those barriers, and to claim a perfectly new territory, which nowhere recognises any demarcation at all. Here transcendental and transcendent do not mean the same thing. The principles of the pure understanding, which we explained before, are meant to be only of empirical, and not of transcendental application, that is, they cannot transcend the limits of experience. A principle, on the contrary, which removes these landmarks, nay, insists on our transcending them, is called transcendent. If our critique succeeds in laying bare the illusion of those pretended principles, the other principles of a purely empirical use may, in opposition to the former, be called immanent.

Logical illusion, which consists in a mere imitation of the forms of reason (the illusion of sophistic syllogisms), arises entirely from want of attention to logical rules. It disappears at once, when our attention [p. 297] is roused. Transcendental illusion, on the contrary, does not disappear, although it has been shown up, and its worthlessness rendered clear by means of transcendental criticism, as, for instance, the illusion inherent in the proposition that the world must have a beginning in time. The cause of this is that there exists in our reason (considered subjectively as a faculty of human knowledge) principles and maxims of its use, which have the appearance of objective principles, and lead us to mistake the subjective necessity of a certain connection of our concepts in favour of the understanding for an objective necessity in the determination of things by themselves. This illusion is as impossible to avoid as it is to prevent the sea from appearing to us higher at a distance than on the shore, because we see it by higher rays of light; or to prevent the moon from appearing, even to an astronomer, larger at its rising, although he is not deceived by that illusion.

Transcendental Dialectic must, therefore, be content to lay bare the illusion of transcendental judgments and guarding against its deceptions — but it will never succeed in removing the transcendental illusion (like the logical), and putting an end to it altogether. [p. 298] For we have here to deal with a natural and inevitable illusion, which itself rests on subjective principles, representing them to us as objective, while logical Dialectic, in removing sophisms, has to deal merely with a mistake in applying the principles, or with an artificial illusion produced by an imitation of them. There exists, therefore, a natural and inevitable Dialectic of pure reason, not one in which a mere bungler might get entangled from want of knowledge, or which a sophist might artificially devise to confuse rational people, but one that is inherent in, and inseparable from human reason, and which, even after its illusion has been exposed, will never cease to fascinate our reason, and to precipitate it into momentary errors, such as require to be removed again and again.

2.

Of Pure Reason, as the Seat of Transcendental Illusion

A.

Of Reason in General

All our knowledge begins with the senses, proceeds thence to the understanding, and ends with reason. There is nothing higher than reason, for working up the material of intuition, and comprehending it under the highest unity of thought. As it here becomes [p. 299] necessary to give a definition of that highest faculty of knowledge, I begin to feel considerable misgivings. There is of reason, as there is of the understanding, a purely formal, that is logical use, in which no account is taken of the contents of knowledge; but there is also a real use, in so far as reason itself contains the origin of certain concepts and principles, which it has not borrowed either from the senses or from the understanding. The former faculty has been long defined by logicians as the faculty of mediate conclusions, in contradistinction to immediate ones (consequentiae immediatae); but this does not help us to understand the latter, which itself produces concepts. As this brings us face to face with the division of reason into a logical and a transcendental faculty, we must look for a higher concept for this source of knowledge, to comprehend both concepts: though, according to the analogy of the concepts of the understanding, we may expect that the logical concept will give us the key to the transcendental, and that the table of the functions of the former will give us the genealogical outline of the concepts of reason.

In the first part of our transcendental logic we defined the understanding as the faculty of rules, and we now distinguish reason from it, by calling it the faculty of principles. [p. 300]

The term principle is ambiguous, and signifies commonly some kind of knowledge only that may be used as a principle, though in itself, and according to its origin, it is no principle at all. Every general proposition, even though it may have been derived from experience (by induction), may serve as a major in a syllogism of reason; but it is not on that account a principle. Mathematical axioms, as, for instance, that between two points there can be only one straight line, constitute even general knowledge a priori, and may therefore, with reference to the cases which can be brought under them, rightly be called principles. Nevertheless it would be wrong to say, that this property of a straight line, in general and by itself, is known to us from principles, for it is known from pure intuition only.

I shall therefore call it knowledge from principles, whenever we know the particular in the general, by means of concepts. Thus every syllogism of reason is a form of deducing some kind of knowledge from a principle, because the major always contains a concept which enables us to know, according to a principle, everything that can be comprehended under the conditions of that concept. As every general knowledge may serve as a major in such a syllogism, and as the understanding supplies such general propositions a priori, these no doubt may, with reference to their possible use, be called principles. [p. 301]

But, if we consider these principles of the pure understanding in themselves, and according to their origin, we find that they are anything rather than knowledge from concepts. They would not even be possible a priori, unless we relied on pure intuition (in mathematics) or on conditions of a possible experience in general. That everything which happens has a cause, can by no means be concluded from the concept of that which happens; on the contrary, that very principle shows in what manner alone we can form a definite empirical concept of that which happens.

It is impossible therefore for the understanding to supply us with synthetical knowledge from concepts, and it is really that kind of knowledge which I call principles absolutely; while all general propositions may be called principles relatively.

It is an old desideratum, which at some time, however distant, may be realised, that, instead of the endless variety of civil laws, their principles might be discovered, for thus alone the secret might be found of what is called simplifying legislation. Such laws, however, are only limitations of our freedom under conditions by which it always agrees with itself; they refer to something which is entirely our own work, and of which we ourselves can be the cause, by means of these concepts. But that objects in themselves, as for instance material nature, should be subject to principles, and be determined according [p. 302] to mere concepts, is something, if not impossible, at all events extremely contradictory. But be that as it may (for on this point we have still all investigations before us), so much at least is clear, that knowledge from principles (by itself) is something totally different from mere knowledge of the understanding, which, in the form of a principle, may no doubt precede other knowledge, but which by itself (in so far as it is synthetical) is not based on mere thought, nor contains anything general, according to concepts.

If the understanding is a faculty for producing unity among phenomena, according to rules, reason is the faculty for producing unity among the rules of the understanding, according to principles. Reason therefore never looks directly to experience, or to any object, but to the understanding, in order to impart a priori through concepts to its manifold kinds of knowledge a unity that may be called the unity of reason, and is very different from the unity which can be produced by the understanding.

This is a general definition of the faculty of reason, so far as it was possible to make it intelligible without the help of illustrations, which are to be given hereafter.

B.

Of the Logical Use of Reason [p. 303]

A distinction is commonly made between what is immediately known and what is only inferred. That in a figure bounded by three straight lines there are three angles, is known immediately, but that these angles together are equal to two right angles, is only inferred. As we are constantly obliged to infer, we grow so accustomed to it, that in the end we no longer perceive this difference, and as in the case of the so-called deceptions of the senses, often mistake what we have only inferred for something perceived immediately. In every syllogism there is first a fundamental proposition; secondly, another deduced from it; and lastly, the conclusion (consequence), according to which the truth of the latter is indissolubly connected with the truth of the former. If the judgment or the conclusion is so clearly contained in the first that it can be inferred from it without the mediation or intervention of a third representation, the conclusion is called immediate (consequentia immediata): though I should prefer to call it a conclusion of the understanding. But if, besides the fundamental knowledge, another judgment is required to bring out the consequence, then the conclusion is called a conclusion of reason. In the proposition ‘all men are mortal,’ the following propositions are contained: some men are mortal; or some mortals are men; or nothing that is immortal is a man. These are therefore immediate [p. 304] inferences from the first. The proposition, on the contrary, all the learned are mortal, is not contained in the fundamental judgment, because the concept of learned does not occur in it, and can only be deduced from it by means of an intervening judgment.

In every syllogism I first think a rule (the major) by means of the understanding. I then bring some special knowledge under the condition of the rule (the minor) by means of the faculty of judgment, and I finally determine my knowledge through the predicate of the rule (conclusio), that is, a priori, by means of reason. It is therefore the relation represented by the major proposition, as the rule, between knowledge and its condition, that constitutes the different kinds of syllogism. Syllogisms are therefore threefold, like all judgments, differing from each other in the manner in which they express the relation of knowledge in the understanding, namely, categorical, hypothetical, and disjunctive.

If, as often happens, the conclusion is put forward as a judgment, in order to see whether it does not follow from other judgments by which a perfectly different object is conceived, I try to find in the understanding the assertion of that conclusion, in order to see whether it does not exist in it, under certain conditions, according to a general rule. If I find such a condition, and if the object of the conclusion can be brought under the given [p. 305] condition, then that conclusion follows from the rule which is valid for other objects of knowledge also. Thus we see that reason, in forming conclusions, tries to reduce the great variety of the knowledge of the understanding to the smallest number of principles (general conditions), and thereby to produce in it the highest unity.

C.

Of the Pure Use of Reason

The question to which we have at present to give an answer, though a preliminary one only, is this, whether reason can be isolated and thus constitute by itself an independent source of concepts and judgments, which spring from it alone, and through which it has reference to objects, or whether it is only a subordinate faculty for imparting a certain form to any given knowledge, namely, a logical form, a faculty whereby the cognitions of the understanding are arranged among themselves only, and lower rules placed under higher ones (the condition of the latter comprehending in its sphere the condition of the former) so far as all this can be done by their comparison. Variety of rules with unity of principles is a requirement of reason for the purpose of bringing the understanding into perfect agreement with itself, just as the understanding brings the variety of intuition under concepts, and thus imparts to intuition a connected form. Such a principle however prescribes no law to the objects [p. 306] themselves, nor does it contain the ground on which the possibility of knowing and determining objects depends. It is merely a subjective law of economy, applied to the stores of our understanding; having for its purpose, by means of a comparison of concepts, to reduce the general use of them to the smallest possible number, but without giving us a right to demand of the objects themselves such a uniformity as might conduce to the comfort and the extension of our understanding, or to ascribe to that maxim any objective validity. In one word, the question is, whether reason in itself, that is pure reason, contains synthetical principles and rules a priori, and what those principles are?

The merely formal and logical procedure of reason in syllogisms gives us sufficient hints as to the ground on which the transcendental principle of synthetical knowledge, by means of pure reason, is likely to rest.

First, a syllogism, as a function of reason, does not refer to intuitions in order to bring them under rules (as the understanding does with its categories), but to concepts and judgments. Although pure reason refers in the end to objects, it has no immediate relation to them and their intuition, but only to the understanding and its judgments, these having a direct relation to the [p. 307] senses and their intuition, and determining their objects. Unity of reason is therefore never the unity of a possible experience, but essentially different from it, as the unity of the understanding. That everything which happens has a cause, is not a principle discovered or prescribed by reason, it only makes the unity of experience possible, and borrows nothing from reason, which without this relation to possible experience could never, from mere concepts, have prescribed such a synthetical unity.

Secondly. Reason, in its logical employment, looks for the general condition of its judgment (the conclusion), and the syllogism produced by reason is itself nothing but a judgment by means of bringing its condition under a general rule (the major). But as this rule is again liable to the same experiment, reason having to seek, as long as possible, the condition of a condition (by means of a prosyllogism), it is easy to see that it is the peculiar principle of reason (in its logical use) to find for every conditioned knowledge of the understanding the unconditioned, whereby the unity of that knowledge may be completed.

This logical maxim, however, cannot become a principle of pure reason, unless we admit that, whenever the condition is given, the whole series of conditions, subordinated to one another, a series, which consequently is [p. 308] itself unconditioned, is likewise given (that is, is contained in the object and its connection).

Such a principle of pure reason, however, is evidently synthetical; for analytically the conditioned refers no doubt to some condition, but not to the unconditioned. From this principle several other synthetical propositions also must arise of which the pure understanding knows nothing; because it has to deal with objects of a possible experience only, the knowledge and synthesis of which are always conditioned. The unconditioned, if it is really to be admitted, has to be especially considered with regard to all the determinations which distinguish it from whatever is conditioned, and will thus supply material for many a synthetical proposition a priori.

The principles resulting from this highest principle of pure reason will however be transcendent, with regard to all phenomena; that is to say, it will be impossible ever to make any adequate empirical use of such a principle. It will thus be completely different from all principles of the understanding, the use of which is entirely immanent and directed to the possibility of experience only. The task that is now before us in the transcendental Dialectic which has to be developed from sources deeply hidden in the human reason, is this: to discover the correctness or otherwise the falsehood of the principle that the series of conditions (in the synthesis of phenomena, or of objective thought in general) extends to the unconditioned, and what consequences result therefrom with regard to the empirical use of the understanding: — to find [p. 309] out whether there is really such an objectively valid principle of reason, and not only, in place of it, a logical rule which requires us, by ascending to ever higher conditions, to approach their completeness, and thus to bring the highest unity of reason, which is possible to us, into our knowledge: to find out, I say, whether, by some misconception, a mere tendency of reason has not been mistaken for a transcendental principle of pure reason, postulating, without sufficient reflection, absolute completeness in the series of conditions in the objects themselves, and what kind of misconceptions and illusions may in that case have crept into the syllogisms of reason, the major proposition of which has been taken over from pure reason (being perhaps a petitio rather than a postulatum), and which ascend from experience to its conditions. We shall divide it into two parts, of which the first will treat of the transcendent concepts of pure reason, the second of transcendent and dialectical syllogisms.

BOOK I

OF THE CONCEPTS OF PURE REASON [p. 310]

Whatever may be thought of the possibility of concepts of pure reason, it is certain that they are not simply obtained by reflection, but by inference. Concepts of the understanding exist a priori, before experience, and for the sake of it, but they contain nothing but the unity of reflection applied to phenomena, so far as they are necessarily intended for a possible empirical consciousness. It is through them alone that knowledge and determination of an object become possible. They are the first to give material for conclusions, and they are not preceded by any concepts a priori of objects from which they could themselves be deduced. Their objective reality however depends on this, that because they constitute the intellectual form of all experience, it is necessary that their application should always admit of being exhibited in experience.

The very name, however, of a concept of reason gives a kind of intimation that it is not intended to be limited to experience, because it refers to a kind of knowledge of which every empirical knowledge is a part only (it may be, the whole of possible experience or of its empirical [p. 311] synthesis): and to which all real experience belongs, though it can never fully attain to it. Concepts of reason serve for conceiving or comprehending; concepts of the understanding for understanding (perceptions). If they contain the unconditioned, they refer to something to which all experience may belong, but which itself can never become an object of experience; — something to which reason in its conclusions from experience leads up, and by which it estimates and measures the degree of its own empirical use, but which never forms part of empirical synthesis. If such concepts possess, notwithstanding, objective validity, they may be called conceptus ratiocinati (concepts legitimately formed); if they have only been surreptitiously obtained, by a kind of illusory conclusion, they may be called conceptus ratiocinantes (sophistical concepts). But as this subject can only be fully treated in the chapter on the dialectical conclusions of pure reason, we shall say no more of it now, but shall only, as we gave the name of categories to the pure concepts of the understanding, give a new name to the concepts of pure reason, and call them transcendental ideas, a name that has now to be explained and justified. [p 312]

First Section

Of Ideas in General

In spite of the great wealth of our languages, a thoughtful mind is often at a loss for an expression that should square exactly with its concept; and for want of which he cannot make himself altogether intelligible, either to others or to himself. To coin new words is to arrogate to oneself legislative power in matters of language, a proceeding which seldom succeeds, so that, before taking so desperate a step, it is always advisable to look about, in dead and learned languages, whether they do not contain such a concept and its adequate expression. Even if it should happen that the original meaning of the word had become somewhat uncertain, through carelessness on the part of its authors, it is better nevertheless to determine and fix the meaning which principally belonged to it (even if it should remain doubtful whether it was originally used exactly in that meaning), than to spoil our labour by becoming unintelligible.

Whenever therefore there exists one single word only for a certain concept, which, in its received meaning, exactly covers that concept, and when it is of [p. 313] great consequence to keep that concept distinct from other related concepts, we ought not to be lavish in using it nor employ it, for the sake of variety only, as a synonyme in the place of others, but carefully preserve its own peculiar meaning, as otherwise it may easily happen that the expression ceases to attract special attention, and loses itself in a crowd of other words of very different import, so that the thought, which that expression alone could have preserved, is lost with it.

From the way in which Plato uses the term idea, it is easy to see that he meant by it something which not only was never borrowed from the senses, but which even far transcends the concepts of the understanding, with which Aristotle occupied himself, there being nothing in experience corresponding to the ideas. With him the ideas are archetypes of things themselves, not only, like the categories, keys to possible experiences. According to his opinion they flowed out from the highest reason, which however exists no longer in its original state, but has to recall, with difficulty, the old but now very obscure ideas, which it does by means of reminiscence, commonly called philosophy. I shall not enter here on any literary discussions in order to determine the exact meaning which the sublime philosopher himself connected with that expression. I shall only remark, that it is by no [p. 314] means unusual, in ordinary conversations, as well as in written works, that by carefully comparing the thoughts uttered by an author on his own subject, we succeed in understanding him better than he understood himself, because he did not sufficiently define his concept, and thus not only spoke, but sometimes even thought, in opposition to his own intentions.

Plato knew very well that our faculty of knowledge was filled with a much higher craving than merely to spell out phenomena according to a synthetical unity, and thus to read and understand them as experience. He knew that our reason, if left to itself, tries to soar up to knowledge to which no object that experience may give can ever correspond; but which nevertheless is real, and by no means a mere cobweb of the brain.

Plato discovered his ideas principally in what is practical,1 that is, in what depends on freedom, which again belongs to a class of knowledge which is a [p. 315] peculiar product of reason. He who would derive the concept of virtue from experience, and would change what at best could only serve as an example or an imperfect illustration, into a type and a source of knowledge (as many have really done), would indeed transform virtue into an equivocal phantom, changing according to times and circumstances, and utterly useless to serve as a rule. Everybody can surely perceive that, when a person is held up to us as a model of virtue, we have always in our own mind the true original with which we compare this so-called model, and estimate it accordingly. The true original is the idea of virtue, in regard to which all possible objects of experience may serve as examples (proofs of the practicability, in a certain degree, of that which is required by the concept of reason), but never as archetypes. That no man can ever act up to the pure idea of virtue does not in the least prove the chimerical nature of that concept; for every judgment as to the moral worth or unworth of actions is possible by means of that idea only, which forms, therefore, the necessary foundation for every approach to moral perfection, however far the impediments inherent in human nature, the extent of which it is difficult to determine, may keep us removed from it.

The Platonic Republic has been supposed to [p. 316] be a striking example of purely imaginary perfection. It has become a byword, as something that could exist in the brain of an idle thinker only, and Brucker thinks it ridiculous that Plato could have said that no prince could ever govern well, unless he participated in the ideas. We should do better, however, to follow up this thought and endeavour (where that excellent philosopher leaves us without his guidance) to place it in a clearer light by our own efforts, rather than to throw it aside as useless, under the miserable and very dangerous pretext of its impracticability. A constitution founded on the greatest possible human freedom, according to laws which enable the freedom of each individual to exist by the side of the freedom of others (without any regard to the highest possible human happiness, because that must necessarily follow by itself), is, to say the least, a necessary idea, on which not only the first plan of a constitution or a state, but all laws must be based, it being by no means necessary to take account from the beginning of existing impediments, which may owe their origin not so much to human nature itself as to the actual neglect of true ideas in legislation. For nothing can be more mischievous and more unworthy a philosopher than the vulgar appeal to what is called adverse experience, which possibly might never have existed, if at the proper time institutions had been framed according to those ideas, and not according to crude [p. 317] concepts, which, because they were derived from experience only, have marred all good intentions. The more legislation and government are in harmony with that idea, the rarer, no doubt, punishments would become; and it is therefore quite rational to say (as Plato did), that in a perfect state no punishments would be necessary. And though this can never be realised, yet the idea is quite correct which sets up this maximum as an archetype, in order thus to bring our legislative constitutions nearer and nearer to the greatest possible perfection. Which may be the highest degree where human nature must stop, and how wide the chasm may be between the idea and its realisation, no one can or ought to determine, because it is this very freedom that may be able to transcend any limits hitherto assigned to it.

It is not only, however, where human reason asserts its free causality and ideas become operative agents (with regard to actions and their objects), that is to say, in the sphere of ethics, but also in nature itself, that Plato rightly discovered clear proofs of its origin from ideas. A plant, an animal, the regular plan of the cosmos (most likely therefore the whole order of nature), show clearly that they are possible according to ideas only; [p. 318] and that though no single creature, under the singular conditions of its existence, can fully correspond with the idea of what is most perfect of its kind (as little as any individual man with the idea of humanity, which, for all that, he carries in his mind as the archetype of all his actions), those ideas are nevertheless determined throughout in the highest understanding each by itself as unchangeable, and are in fact the original causes of things, although it can only be said of the whole of them, connected together in the universe, that it is perfectly adequate to the idea. If we make allowance for the exaggerated expression, the effort of the philosopher to ascend from the mere observing and copying of the physical side of nature to an architectonic system of it, teleologically, that is according to ideas, deserves respect and imitation, while with regard to the principles of morality, legislation, and religion, where it is the ideas themselves that make experience of the good possible, though they can never be fully realised in experience, such efforts are of very eminent merit, which those only fail to recognise who attempt to judge it according to empirical rules, the very validity of which, as principles, was meant to be denied by Plato. With regard to nature, it is experience no doubt which supplies us with rules, and is the foundation of all truth: with regard to moral laws, on the contrary, experience is, alas! but the source of illusion; and it is altogether reprehensible to derive or limit the laws of what we [p. 319] ought to do according to our experience of what has been done.

Instead of considering these subjects, the full development of which constitutes in reality the peculiar character and dignity of philosophy, we have to occupy ourselves at present with a task less brilliant, though not less useful, of building and strengthening the foundation of that majestic edifice of morality, which at present is undermined by all sorts of mole-tracks, the work of our reason, which thus vainly, but always with the same confidence, is searching for buried treasures. It is our duty at present to acquire an accurate knowledge of the transcendental use of the pure reason, its principles and ideas, in order to be able to determine and estimate correctly their influence and value. But before I leave this preliminary introduction, I beg those who really care for philosophy (which means more than is commonly supposed), if they are convinced by what I have said and shall still have to say, to take the term idea, in its original meaning, under their special protection, so that it should no longer be lost among other expressions, by which all sorts of representations are loosely designated, to the great detriment of philosophy. There is no lack of names adequate to express every kind of representation, without our having to encroach on the property of others. I shall [p. 320] give a graduated list of them. The whole class may be called representation (repraesentatio). Under it stands conscious representation, perception (perceptio). A perception referring to the subject only, as a modification of his state, is sensation (sensatio), while an objective sensation is called knowledge, cognition (cognitio). Cognition is either intuition or concept (intuitus vel conceptus). The former refers immediately to an object and is singular, the latter refers to it mediately, that is, by means of a characteristic mark that can be shared by several things in common. A concept is either empirical or pure, and the pure concept, so far as it has its origin in the understanding only (not in the pure image of sensibility) is called notion (notio). A concept formed of notions and transcending all possible experience is an idea, or a concept of reason. To any one who has once accustomed himself to these distinctions, it must be extremely irksome to hear the representation of red colour called an idea, though it could not even be rightly called a notion (a concept of the understanding).

Second Section

Of Transcendental Ideas[p. 321]

We had an instance in our transcendental Analytic, how the mere logical form of our knowledge could contain the origin of pure concepts a priori, which represent objects antecedently to all experience, or rather indicate a synthetical unity by which alone an empirical knowledge of objects becomes possible. The form of judgments (changed into a concept of the synthesis of intuitions) gave us the categories that guide and determine the use of the understanding in every experience. We may expect, therefore, that the form of the syllogisms, if referred to the synthetical unity of intuitions, according to the manner of the categories, will contain the origin of certain concepts a priori, to be called concepts of pure reason, or transcendental ideas, which ought to determine the use of the understanding within the whole realm of experience, according to principles.

The function of reason in its syllogisms consists in the universality of cognition, according to concepts, and the syllogism itself is in reality a judgment, determined [p. 322] a priori in the whole extent of its condition. The proposition ‘Caius is mortal,’ might be taken from experience, by means of the understanding only. But what we want is a concept, containing the condition under which the predicate (assertion in general) of that judgment is given (here the concept of man), and after I have arranged it under this condition, taken in its whole extent (all men are mortal), I proceed to determine accordingly the knowledge of my object (Caius is mortal).

What we are doing therefore in the conclusion of a syllogism is to restrict the predicate to a certain object, after we have used it first in the major, in its whole extent, under a certain condition. This completeness of its extent, in reference to such a condition, is called universality (universalitas); and to this corresponds, in the synthesis of intuitions, the totality (universitas) of conditions. The transcendental concept of reason is, therefore, nothing but the concept of the totality of the conditions of anything given as conditioned. As therefore the unconditioned alone renders a totality of conditions possible, and as conversely the totality of conditions must always be unconditioned, it follows that a pure concept of reason in general may be explained as a concept of the unconditioned, so far as it contains a basis for the synthesis of the conditioned.

As many kinds of relations as there are, which [p. 323] the understanding represents to itself by means of the categories, so many pure concepts of the reason we shall find, that is, first, the unconditioned of the categorical synthesis in a subject; secondly, the unconditioned of the hypothetical synthesis of the members of a series; thirdly, the unconditioned of the disjunctive synthesis of the parts of a system.

There are exactly as many kinds of syllogisms, each of which tries to advance by means of pro-syllogisms to the unconditioned: the first to the subject, which itself is no longer a predicate; the second to the presupposition, which presupposes nothing else; and the third to an aggregate of the members of a division, which requires nothing else, in order to render the division of the concept complete. Hence the pure concepts of reason implying totality in the synthesis of the conditions are necessary, at least as problems, in order to carry the unity of the understanding to the unconditioned, if that is possible, and they are founded in the nature of human reason, even though these transcendental concepts may be without any proper application in concreto, and thus have no utility beyond bringing the understanding into a direction where its application, being extended as far as possible, is brought throughout in harmony with itself.

Whilst speaking here of the totality of conditions, [p. 324] and of the unconditioned, as the common title of all the concepts of reason, we again meet with a term which we cannot do without, but which, by long abuse, has become so equivocal that we cannot employ it with safety. The term absolute is one of those few words which, in their original meaning, were fitted to a concept, which afterwards could not be exactly fitted with any other word of the same language, and the loss of which, or what is the same, the loose employment of which, entails the loss of the concept itself, and that of a concept with which reason is constantly occupied, and cannot dispense with without real damage to all transcendental investigations. At present the term absolute is frequently used simply in order to indicate that something applies to an object, considered in itself, and thus as it were internally. In this way absolutely possible would mean that something is possible in itself (interné), which in reality is the least that could be said of it. It is sometimes used also to indicate that something is valid in all respects (without limitation), as people speak of absolute sovereignty. In this way absolutely possible would mean that which is possible in all respects, and this is again the utmost that could be said of the possibility of a thing. It is true that these two significations [p. 325] sometimes coincide, because something that is internally impossible is impossible also in every respect, and therefore absolutely impossible. But in most cases they are far apart, and I am by no means justified in concluding that, because something is possible in itself, it is possible also in every respect, that is, absolutely possible. Nay, with regard to absolute necessity, I shall be able to show hereafter that it by no means always depends on internal necessity, and that the two cannot therefore be considered synonymous. No doubt, if the opposite of a thing is intrinsically impossible, that opposite is also impossible in every respect, and the thing itself therefore absolutely necessary. But I cannot conclude conversely, that the opposite of what is absolutely necessary is internally impossible, or that the absolute necessity of things is the same as an internal necessity. For in certain cases that internal necessity is an entirely empty expression, with which we cannot connect the least concept, while that of the necessity of a thing in every respect (with regard to all that is possible) implies very peculiar determinations. As therefore the loss of a concept which has acted a great part in speculative philosophy can never be indifferent to philosophers, I hope they will also take some interest in the definition and careful preservation of the term with which that concept is connected.

I shall therefore use the term absolute in this [p. 326] enlarged meaning only, in opposition to that which is valid relatively and in particular respects only, the latter being restricted to conditions, the former free from any restrictions whatsoever.

It is then the absolute totality in the synthesis of conditions at which the transcendental concept of reason aims, nor does it rest satisfied till it has reached that which is unconditioned absolutely and in every respect. Pure reason leaves everything to the understanding, which has primarily to do with the objects of intuition, or rather their synthesis in imagination. It is only the absolute totality in the use of the concepts of the understanding, which reason reserves for itself, while trying to carry the synthetical unity, which is realised in the category, to the absolutely unconditioned. We might therefore call the latter the unity of the phenomena in reason, the former, which is expressed by the category, the unity in the understanding. Hence reason is only concerned with the use of the understanding, not so far as it contains the basis of possible experience (for the absolute totality of conditions is not a concept that can be used in experience, because no experience is unconditioned), but in order to impart to it a direction towards a certain unity of which the understanding knows nothing, and which is meant to comprehend all acts of the understanding, with regard to any object, into an [p. 327] absolute whole. On this account the objective use of the pure concepts of reason must always be transcendent: while that of the pure concepts of the understanding must always be immanent, being by its very nature restricted to possible experience.

By idea I understand the necessary concept of reason, to which the senses can supply no corresponding object. The concepts of reason, therefore, of which we have been speaking, are transcendental ideas. They are concepts of pure reason, so far as they regard all empirical knowledge as determined by an absolute totality of conditions. They are not mere fancies, but supplied to us by the very nature of reason, and referring by necessity to the whole use of the understanding. They are, lastly, transcendent, as overstepping the limits of all experience which can never supply an object adequate to the transcendental idea. If we speak of an idea, we say a great deal with respect to the object (as the object of the pure understanding) but very little with respect to the subject, that is, with respect to its reality under empirical conditions, because an idea, being the concept of a maximum, can never be adequately given in concreto. As the latter is really the whole aim in the merely speculative use of reason, and as [p. 328] the mere approaching a concept, which in reality can never be reached, is the same as if the concept were missed altogether, people, when speaking of such a concept, are wont to say, it is an idea only. Thus one might say, that the absolute whole of all phenomena is an idea only, for as we can never form a representation of such a whole, it remains a problem without a solution. In the practical use of the understanding, on the contrary, where we are only concerned with practice, according to rules, the idea of practical reason can always be realised in concreto, although partially only; nay, it is the indispensable condition of all practical use of reason. The practical realisation of the idea is here always limited and deficient, but these limits cannot be defined, and it always remains under the influence of a concept, implying absolute completeness and perfection. The practical idea is therefore in this case truly fruitful, and, with regard to practical conduct, indispensable and necessary. In it pure reason becomes a cause and active power, capable of realising what is contained in its concept. Hence we cannot say of wisdom, as if contemptuously, that it is an idea only, but for the very reason that it contains the idea of the necessary unity of all possible aims, it must determine all practical acts, as an original and, at least, limitative condition.

Although we must say that all transcendental [p. 329] concepts of reason are ideas only, they are not therefore to be considered as superfluous and useless. For although we cannot by them determine any object, they may nevertheless, even unobserved, supply the understanding with a canon or rule of its extended and consistent use, by which, though no object can be better known than it is according to its concepts, yet the understanding may be better guided onwards in its knowledge, not to mention that they may possibly render practicable a transition from physical to practical concepts, and thus impart to moral ideas a certain strength and connection with the speculative knowledge of reason. On all this more light will be thrown in the sequel.

For our present purposes we are obliged to set aside a consideration of these practical ideas, and to treat of reason in its speculative, or rather, in a still more limited sense, its purely transcendental use. Here we must follow the same road which we took before in the deduction of the categories; that is, we must consider the logical form of all knowledge of reason, and see whether, perhaps, by this logical form, reason may become a source of concepts also, which enable us to regard objects in themselves, as determined synthetically a priori in relation to one or other of the functions of reason.

Reason, if considered as a faculty of a certain [p. 330] logical form of knowledge, is the faculty of concluding, that is, of judging mediately, by bringing the condition of a possible under the condition of a given judgment. The given judgment is the general rule (major). Bringing the condition of another possible judgment under the condition of the rule, which may be called subsumption, is the minor, and the actual judgment, which contains the assertion of the rule in the subsumed case, is the conclusion. We know that the rule asserts something as general under a certain condition. The condition of the rule is then found to exist in a given case. Then that which, under that condition, was asserted as generally valid, has to be considered as valid in that given case also, which complies with that condition. It is easy to see therefore that reason arrives at knowledge by acts of the understanding, which constitute a series of conditions. If I arrive at the proposition that all bodies are changeable, only by starting from a more remote knowledge (which does not yet contain the concept of body, but a condition of such a concept only), namely, that all which is composite is changeable; and then proceed to something less remotely known, and depending on the former, namely, that bodies are composite; and, lastly, only advance to a third proposition, connecting the more remote knowledge (changeable) with the given case, and conclude that bodies therefore are changeable, we see that we have [p. 331] passed through a series of conditions (premisses) before we arrived at knowledge (conclusion). Every series, the exponent of which (whether of a categorical or hypothetical judgment) is given, can be continued, so that this procedure of reason leads to ratiocinatio polysyllogistica, a series of conclusions which, either on the side of the conditions (per prosyllogismos) or of the conditioned (per episyllogismos), may be continued indefinitely.

It is soon perceived, however, that the chain or series of prosyllogisms, that is, of knowledge deduced on the side of reasons or conditions of a given knowledge, in other words, the ascending series of syllogisms, must stand in a very different relation to the faculty of reason from that of the descending series, that is, of the progress of reason on the side of the conditioned, by means of episyllogisms. For, as in the former case the knowledge embodied in the conclusion is given as conditioned only, it is impossible to arrive at it by means of reason in any other way except under the supposition at least that all the members of the series on the side of the conditions are given (totality in the series of premisses), because it is under that supposition only that the contemplated judgment a priori is possible; while on the side of the conditioned, or of the inferences, we can only think [p. 332] of a growing series, not of one presupposed as complete or given, that is, of a potential progression only. Hence, when our knowledge is considered as conditioned, reason is constrained to look upon the series of conditions in the ascending line as complete, and given in their totality. But if the same knowledge is looked upon at the same time as a condition of other kinds of knowledge, which constitute among themselves a series of inferences in a descending line, it is indifferent to reason how far that progression may go a parte posteriori, or whether a totality of the series is possible at all, because such a series is not required for the conclusion in hand, which is sufficiently determined and secured on grounds a parte priori. Whether the series of premisses on the side of the conditions have a something that stands first as the highest condition, or whether it be without limits a parte priori, it must at all events contain a totality of conditions, even though we should never succeed in comprehending it; and the whole series must be unconditionally true, if the conditioned, which is considered as a consequence resulting from it, is to be accepted as true. This is a demand of reason which pronounces its knowledge as determined a priori and as necessary, either in itself, and in that case it requires no reasons, or, if derivative, as a member of a series of reasons, which itself is unconditionally true.

Third Section

System of Transcendental Ideas[p. 333]

We are not at present concerned with logical Dialectic, which takes no account of the contents of knowledge, and has only to lay bare the illusions in the form of syllogisms, but with transcendental Dialectic, which is supposed to contain entirely a priori the origin of certain kinds of knowledge, arising from pure reason, and of certain deduced concepts, the object of which can never be given empirically, and which therefore lie entirely outside the domain of the pure understanding. We gathered from the natural relation which must exist between the transcendental and the logical use of our knowledge, in syllogisms as well as in judgments, that there must be three kinds of dialectic syllogisms, and no more, corresponding to the three kinds of conclusion by which reason may from principles arrive at knowledge, and that in all of these it is the object of reason to ascend from the conditioned synthesis, to which the understanding is always restricted, to an unconditioned synthesis, which the understanding can never reach.

The relations which all our representations share in common are, 1st, relation to the subject; 2ndly, the relation to objects, either as phenomena, or as objects [p. 334] of thought in general. If we connect this subdivision with the former division, we see that the relation of the representations of which we can form a concept or an idea can only be threefold: 1st, the relation to the subject; 2ndly, the relation to the manifold of the phenomenal object; 3rdly, the relation to all things in general.

All pure concepts in general aim at a synthetical unity of representations, while concepts of pure reason (transcendental ideas) aim at unconditioned synthetical unity of all conditions. All transcendental ideas therefore can be arranged in three classes: the first containing the absolute (unconditioned) unity of the thinking subject; the second the absolute unity of the series of conditions of phenomena; the third the absolute unity of the condition of all objects of thought in general.

The thinking subject is the object-matter of psychology, the system of all phenomena (the world) the object-matter of cosmology, and the being which contains the highest condition of the possibility of all that can be thought (the Being of all beings), the object-matter of theology. Thus it is pure reason which supplies the idea of a transcendental science of the soul (psychologia rationalis), of a transcendental science of the world (cosmologia rationalis), and, lastly, of a transcendental science of God (theologia transcendentalis). Even the mere plan of any [p. 335] one of these three sciences does not come from the understanding, even if connected with the highest logical use of reason, that is, with all possible conclusions, leading from one of its objects (phenomenon) to all others, and on to the most remote parts of any possible empirical synthesis, — but is altogether a pure and genuine product or rather problem of pure reason.

What kinds of pure concepts of reason are comprehended under these three titles of all transcendental ideas will be fully explained in the following chapter. They follow the thread of the categories, for pure reason never refers direct to objects, but to the concepts of objects framed by the understanding. Nor can it be rendered clear, except hereafter in a detailed explanation, how first, reason simply by the synthetical use of the same function which it employs for categorical syllogisms is necessarily led on to the concept of the absolute unity of the thinking subject; secondly, how the logical procedure in hypothetical syllogisms leads to the idea of something absolutely unconditioned, in a series of given conditions, and how, thirdly, the mere form of the disjunctive syllogism produces necessarily the highest concept of reason, that of a Being of all beings; a thought which, at first sight, seems extremely paradoxical. [p. 336]

No objective deduction, like that given of the categories, is possible with regard to these transcendental ideas; they are ideas only, and for that very reason they have no relation to any object corresponding to them in experience. What we could undertake to give was a subjective deduction1 of them from the nature of reason, and this has been given in the present chapter.

We can easily perceive that pure reason has no other aim but the absolute totality of synthesis on the side of conditions (whether of inherence, dependence, or concurrence), and that it has nothing to do with the absolute completeness on the part of the conditioned. It is the former only which is required for presupposing the whole series of conditions, and thus presenting it a priori to the understanding. If once we have a given condition, complete and unconditioned itself, no concept of reason is required to continue the series, because the understanding takes by itself every step downward from the condition to the conditioned. The transcendental ideas therefore serve only for ascending in the series of conditions till they reach the unconditioned, that is, the principles. With regard to descending to the conditioned, there is no doubt a widely extended logical use which our reason [p. 337] may make of the rules of the understanding, but no transcendental one; and if we form an idea of the absolute totality of such a synthesis (by progressus), as, for instance, of the whole series of all future changes in the world, this is only a thought (ens rationis) that may be thought if we like, but is not presupposed as necessary by reason. For the possibility of the conditioned, the totality of its conditions only, but not of its consequences, is presupposed. Such a concept therefore is not one of the transcendental ideas, with which alone we have to deal.

Finally, we can perceive, that there is among the transcendental ideas themselves a certain connection and unity by which pure reason brings all its knowledge into one system. There is in the progression from our knowledge of ourselves (the soul) to a knowledge of the world, and through it to a knowledge of the Supreme Being, something so natural that it looks like the logical progression of reason from premisses to a conclusion.1 Whether there exists here a real though hidden relationship, such as we saw before between the logical and transcendental use of reason, is also one of the questions the answer to which can only be given in the progress of these investigations. For the present we have achieved what we wished to achieve, by removing the transcendental [p. 338] concepts of reason, which in the systems of other philosophers are generally mixed up with other concepts, without being distinguished even from the concepts of the understanding, out of so equivocal a position; by being able to determine their origin and thereby at the same time their number, which can never be exceeded, and by thus bringing them into a systematic connection, marking out and enclosing thereby a separate field for pure reason.

BOOK II

OF THE DIALECTICAL CONCLUSIONS OF PURE REASON

One may say that the object of a purely transcendental idea is something of which we have no concept, although the idea is produced with necessity according to the original laws of reason. Nor is it possible indeed to form of an object that should be adequate to the demands of reason, a concept of the understanding, that is, a concept which could be shown in any possible experience, and rendered intuitive. It would be better, however, and less [p. 339] liable to misunderstandings, to say that we can have no knowledge of an object corresponding to an idea, but a problematic concept only.

The transcendental (subjective) reality, at least of pure concepts of reason, depends on our being led to such ideas by a necessary syllogism of reason. There will be syllogisms therefore which have no empirical premisses, and by means of which we conclude from something which we know to something else of which we have no concept, and to which, constrained by an inevitable illusion, we nevertheless attribute objective reality. As regards their result, such syllogisms are rather to be called sophistical than rational, although, as regards their origin, they may claim the latter name, because they are not purely fictitious or accidental, but products of the very nature of reason. They are sophistications, not of men, but of pure reason itself, from which even the wisest of men cannot escape. All he can do is, with great effort, to guard against error, though never able to rid himself completely of an illusion which constantly torments and mocks him.

Of these dialectical syllogisms of reason there are therefore three classes only, that is as many as the ideas to which their conclusions lead. In the syllogism [p. 340] of the first class, I conclude from the transcendental concept of the subject, which contains nothing manifold, the absolute unity of the subject itself, of which however I have no concept in this regard. This dialectical syllogism I shall call the transcendental paralogism.

The second class of the so-called sophistical syllogisms aims at the transcendental concept of an absolute totality in the series of conditions to any given phenomenon; and I conclude from the fact that my concept of the unconditioned synthetical unity of the series is always self-contradictory on one side, the correctness of the opposite unity, of which nevertheless I have no concept either. The state of reason in this class of dialectical syllogisms, I shall call the antinomy of pure reason.

Lastly, according to the third class of sophistical syllogisms, I conclude from the totality of conditions, under which objects in general, so far as they can be given to me, must be thought, the absolute synthetical unity of all conditions of the possibility of things in general; that is to say, I conclude from things which I do not know according to their mere transcendental1 concept, a Being of all beings, which I know still less through a transcendental concept, and of the unconditioned necessity of which I can form no concept whatever. This dialectical syllogism of reason I shall call the ideal of pure reason.

CHAPTER I

OF THE PARALOGISMS OF PURE REASON [p. 341]

The logical paralogism consists in the formal faultiness of a conclusion, without any reference to its contents. But a transcendental paralogism arises from a transcendental cause, which drives us to a formally false conclusion. Such a paralogism, therefore, depends most likely on the very nature of human reason, and produces an illusion which is inevitable, though not insoluble.

We now come to a concept which was not inserted in our general list of transcendental concepts, and yet must be reckoned with them, without however changing that table in the least, or proving it to be deficient. This is the concept, or, if the term is preferred, the judgment, I think. It is easily seen, however, that this concept is the vehicle of all concepts in general, therefore of transcendental concepts also, being always comprehended among them, and being itself transcendental also, though without any claim to a special title, inasmuch as it serves only to introduce all thought, as belonging to consciousness. However free that concept may be from all that is empirical (impressions of the senses), it serves [p. 342] nevertheless to distinguish two objects within the nature of our faculty of representation. 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. The term I, as a thinking being, signifies the object of psychology, which may be called the rational science of the soul, supposing that we want to know nothing about the soul except what, independent of all experience (which determines the I more especially and in concreto), can be deduced from the concept of I, so far as it is present in every act of thought.

Now the rational science of the soul is really such an undertaking; for if the smallest empirical element of my thought or any particular perception of my internal state were mixed up with the sources from which that science derives its materials, it would be an empirical, and no longer a purely rational science of the soul. There is therefore a pretended science, founded on the single proposition of I think, and the soundness or unsoundness of which may well be examined in this place, according to the principles of transcendental philosophy. It should not be objected that even in that proposition, which expresses the perception of oneself, I have an internal experience, and that therefore the rational science of the soul, which is founded on it, can never be quite [p. 343] pure, but rests, to a certain extent, on an empirical principle. For this inner perception is nothing more than the mere apperception, I think, without which even all transcendental concepts would be impossible, in which we really say, I think the substance, I think the cause, etc. This internal experience in general and its possibility, or perception in general and its relation to other perceptions, there being no special distinction or empirical determination of it, cannot be regarded as empirical knowledge, but must be regarded as knowledge of the empirical in general, and falls therefore under the investigation of the possibility of all experience, which investigation is certainly transcendental. The smallest object of perception (even pleasure and pain), if added to the general representation of self-consciousness, would at once change rational into empirical psychology.

I think is, therefore, the only text of rational psychology, out of which it must evolve all its wisdom. It is easily seen that this thought, if it is to be applied to any object (my self), cannot contain any but transcendental predicates, because the smallest empirical predicate would spoil the rational purity of the science, and its independence of all experience.

We shall therefore follow the thread of the [p. 344] categories, with this difference, however, that as here the first thing which is given is a thing, the I, a thinking being, we must begin with the category of substance, by which a thing in itself is represented, and then proceed backwards, though without changing the respective order of the categories, as given before in our table. The topic of the rational science of the soul, from which has to be derived whatever else that science may contain, is therefore the following.

All concepts of pure psychology arise from [p. 345] these elements, simply by way of combination, and without the admixture of any other principle. This substance, taken simply as the object of the internal sense, gives us the concept of immateriality; and as simple substance, that of incorruptibility; its identity, as that of an intellectual substance,. gives us personality; and all these three together, spirituality; its relation to objects in space gives us the concept of commercium (intercourse) with bodies; the pure psychology thus representing the thinking substance as the principle of life in matter, that is, as soul (anima), and as the ground of animality; which again, as restricted by spirituality, gives us the concept of immortality.

To these concepts refer four paralogisms of a transcendental psychology, which is falsely supposed to be a science of pure reason, concerning the nature of our thinking being. We can, however, use as the foundation of such a science nothing but the single, and in itself perfectly empty, representation of the I, of which [p. 346] we cannot even say that it is a concept, but merely a consciousness that accompanies all concepts. By this I, or he, or it (the thing), which thinks, nothing is represented beyond a transcendental subject of thoughts = x, which is known only through the thoughts that are its predicates, and of which, apart from them, we can never have the slightest concept, so that we are really turning round it in a perpetual circle, having already to use its representation, before we can form any judgment about it. And this inconvenience is really inevitable, because consciousness in itself is not so much a representation, distinguishing a particular object, but really a form of representation in general, in so far as it is to be called knowledge, of which alone I can say that I think something by it.

It must seem strange, however, from the very beginning, that the condition under which I think, and which therefore is a property of my own subject only, should be valid at the same time for everything which thinks, and that, depending on a proposition which seems to be empirical, we should venture to found the apodictical and general judgment, namely, that everything which thinks is such as the voice of my own consciousness declares it to be within me. The reason of it is, that we are constrained to attribute a priori to things all the qualities which form the conditions, under which alone [p. 347] we are able to think them. Now it is impossible for me to form the smallest representation of a thinking being by any external experience, but I can do it through self-consciousness only. Such objects therefore are nothing but a transference of my own consciousness to other things, which thus, and thus only, can be represented as thinking beings. The proposition I think is used in this case, however, as problematical only; not so far as it may contain the perception of an existence (the Cartesian, cogito, ergo sum), but with regard to its mere possibility, in order to see what properties may be deduced from such a simple proposition with regard to its subject, whether such subject exists or not.

If our knowledge of thinking beings in general, so far as it is derived from pure reason, were founded on more than the cogito, and if we made use at the same time of observations on the play of our thoughts and the natural laws of the thinking self, derived from them, we should have before us an empirical psychology, which would form a kind of physiology of the internal sense, and perhaps explain its manifestations, but would never help us to understand such properties as do not fall under any possible experience (as, for instance, simplicity), or to teach apodictically anything touching the nature of thinking beings in general. It would not therefore be a rational psychology.

As the proposition I think (taken problematically) [p. 348] contains the form of every possible judgment of the understanding, and accompanies all categories as their vehicle, it must be clear that the conclusions to be drawn from it can only contain a transcendental use of the understanding, which declines all admixture of experience, and of the achievements of which, after what has been said before, we cannot form any very favourable anticipations. We shall therefore follow it, with a critical eye, through all the predicaments of pure psychology.1

[The First Paralogism of Substantiality

That the representation of which is the absolute subject of our judgments, and cannot be used therefore as the determination of any other thing, is the substance.

I, as a thinking being, am the absolute subject of all my possible judgments, and this representation of myself can never be used as the predicate of any other thing.

Therefore I, as a thinking being (Soul), am Substance.

Criticism of the First Paralogism of Pure2Psychology

We showed in the analytical portion of transcendental logic, that pure categories, and among them that of substance, have in themselves no objective meaning, unless they rest on some intuition, and are applied to [p. 349] the manifold of such intuitions as functions of synthetical unity. Without this they are merely functions of a judgment without contents. I may say of everything, that it is a substance, so far as I distinguish it from what are mere predicates and determinations. Now in all our thinking the I is the subject, in which thoughts are inherent as determinations only; nor can that I ever be used as a determination of any other thing. Thus everybody is constrained to look upon himself as the substance, and on thinking as the accidents only of his being, and determinations of his state.

But what use are we to make of such a concept of a substance? That I, as a thinking being, continue for myself, and naturally neither arise nor perish, is no legitimate deduction from it; and yet this conclusion would be the only advantage that could be gained from the concept of the substantiality of my own thinking subject, and, but for that, I could do very well without it.

So far from being able to deduce these properties from the pure category of substance, we have on the contrary to observe the permanency of an object in our experience and then lay hold of this permanency, if we wish to apply to it the empirically useful concept of substance. In this case, however, we had no experience to lay hold of, but have only formed a deduction from the concept [p. 350] of the relation which all thinking has to the I, as the common subject to which it belongs. Nor should we, whatever we did, succeed by any certain observation in proving such permanency. For though the I exists in all thoughts, not the slightest intuition is connected with that representation, by which it might be distinguished from other objects of intuition. We may very well perceive therefore that this representation appears again and again in every act of thought, but not that it is a constant and permanent intuition, in which thoughts, as being changeable, come and go.

Hence it follows that in the first syllogism of transcendental psychology reason imposes upon us an apparent knowledge only, by representing the constant logical subject of thought as the knowledge of the real subject in which that knowledge inheres. Of that subject, however, we have not and cannot have the slightest knowledge, because consciousness is that which alone changes representations into thoughts, and in which therefore, as the transcendental subject, all our perceptions must be found. Beside this logical meaning of the I, we have no knowledge of the subject in itself, which forms the substratum and foundation of it and of all our thoughts. In spite of this, the proposition that the soul is a substance may well be allowed to stand, if only we see that this concept cannot help us on in the least or teach us any of the ordinary conclusions of rationalising psychology, as, for [p. 351] instance, the everlasting continuance of the soul amid all changes and even in death, and that it therefore signifies a substance in idea only, and not in reality.

The Second Paralogism of Simplicity

Everything, the action of which can never be considered as the concurrence of several acting things, is simple.

Now the Soul, or the thinking I, is such a thing: —

Therefore, etc.

Criticism of the Second Paralogism of Transcendental Psychology

This is the strong (yet not invulnerable) syllogism among all dialectical syllogisms of pure psychology, not a mere sophism contrived by a dogmatist in order to impart a certain plausibility to his assertions, but a syllogism which seems able to stand the sharpest examination and the gravest doubts of the philosopher. It is this: —

Every composite substance is an aggregate of many substances, and the action of something composite, or that which is inherent in it as such, is an aggregate of many actions or accidents distributed among many substances. An effect due to the concurrence of many acting substances is no doubt possible, if that effect is [p. 352] external only (as, for instance, the motion of a body is the combined motion of all its parts). The case is different however with thoughts, if considered as accidents belonging to a thinking being within. For suppose it is the composite which thinks, then every part of it would contain a part of the thought, and all together only the whole of it. This however is self-contradictory. For as representations, distributed among different beings (like the single words of a verse), never make a whole thought (a verse), it is impossible that a thought should be inherent in something composite, as such. Thought therefore is possible only in a substance which is not an aggregate of many, and therefore absolutely simple.1

What is called the nervus probandi in this argument lies in the proposition that, in order to constitute a thought, the many representations must be comprehended under the absolute unity of the thinking subject. Nobody however can prove this proposition from concepts. For how would he undertake to do it? The proposition [p. 353] that a thought can only be the effect of the absolute unity of a thinking being, cannot be considered as analytical. For the unity of thought, consisting of many representations, is collective, and may, so far as mere concepts are concerned, refer to the collective unity of all co-operating substances (as the movement of a body is the compound movement of all its parts) quite as well as to the absolute unity of the subject. According to the rule of identity it would be impossible therefore to establish the necessity of the presupposition of a simple substance, the thought being composite. That, on the other hand, such a proposition might be established synthetically and entirely a priori from mere concepts, no one will venture to affirm who has once understood the grounds on which the possibility of synthetical propositions a priori rests, as explained by us before.

It is likewise impossible, however, to derive this necessary unity of the subject, as the condition of the possibility of the unity of every thought, from experience. For experience never supplies any necessity of thought, much less the concept of absolute unity. Whence then do we take that proposition on which the whole psychological syllogism of reason rests?

It is manifest that if we wish to represent to ourselves a thinking being, we must put ourselves in its place, and supplant as it were the object which has to be considered by our own subject (which never happens in any [p. 354] other kind of investigation). The reason why we postulate for every thought absolute unity of the subject is because otherwise we could not say of it, I think (the manifold in one representation). For although the whole of a thought may be divided and distributed under many subjects, the subjective I can never thus be divided and distributed, and it is this I which we presuppose in every thought.

As in the former paralogism therefore, so here also, the formal proposition of apperception, I think, remains the sole ground on which rational psychology ventures to undertake the extension of its knowledge. That proposition, however, is no experience, but only the form of apperception inherent in, and antecedent to, every experience, that is a purely subjective condition, having reference to a possible experience only, but by no means the condition of the possibility of the knowledge of objects, and by no means necessary to the concept of a thinking being in general; although it must be admitted that we cannot represent to ourselves another intelligent being without putting ourselves in its place with that formula of our consciousness.

Nor is it true that the simplicity of my self (as a soul) is really deduced from the proposition, I think, for it is already involved in every thought itself. The proposition I am simple must be considered as the immediate [p. 355] expression of apperception, and the so-called syllogism of Cartesius, cogito, ergo sum, is in reality tautological, because cogito (sum cogitans) predicates reality immediately. I am simple means no more than that this representation of I does not contain the smallest trace of manifoldness, but is absolute (although merely logical) unity.

Thus we see that the famous psychological argument is founded merely on the indivisible unity of a representation, which only determines the verb with reference to a person; and it is clear that the subject of inherence is designated transcendentally only by the I, which accompanies the thought, without our perceiving the smallest quality of it, in fact, without our knowing anything about it. It signifies a something in general (a transcendental subject) the representation of which must no doubt be simple, because nothing is determined in it, and nothing can be represented more simple than by the concept of a mere something. The simplicity however of the representation of a subject is not therefore a knowledge of the simplicity of the subject, because no account whatever is taken of its qualities when it is designated by the entirely empty expression I, an expression that can be applied to every thinking subject.

So much is certain therefore that though I [p. 356] always represent by the I an absolute, but only logical, unity of the subject (simplicity), I never know thereby the real simplicity of my subject. We saw that the proposition, I am a substance, signified nothing but the mere category of which I must not make any use (empirically) in concreto. In the same manner, I may well say, I am a simple substance, that is, a substance the representation of which contains no synthesis of the manifold; but that concept, or that proposition also, teaches us nothing at all with reference to myself, as an object of experience, because the concept of substance itself is used as a function of synthesis only, without any intuition to rest on, and therefore without any object, valid with reference to the condition of our knowledge only, but not with reference to any object of it. We shall test the usefulness of this proposition by an experiment.

Everybody must admit that the assertion of the simple nature of the soul can only be of any value in so far as it enables me to distinguish the soul from all matter, and thus to except it from that decay to which matter is at all times subject. It is for that use that our proposition is really intended, and it is therefore often expressed by, the soul is not corporeal. If then I can show that, [p. 357] although we allow to this cardinal proposition of rational psychology (as a mere judgment of reason from pure categories) all objective validity (everything that thinks is simple substance), we cannot make the least use of it, in order to establish the homogeneousness or non-homogeneousness of soul and matter, this will be the same as if I had relegated this supposed psychological truth to the field of mere ideas, without any real or objective use.

We have irrefutably proved in the transcendental Æsthetic that bodies are mere phenomena of our external sense, not things by themselves. We are justified therefore in saying that our thinking subject is not a body, i.e. that, because it is represented by us as an object of the internal sense, it is, so far as it thinks, no object of our external senses, and no phenomenon in space. This means the same as that among external phenomena we can never have thinking beings as such, or ever see their thoughts, their consciousness, their desires, etc., externally. All this belongs to the internal sense. This argument seems indeed so natural and popular that even the commonest understanding has always been led [p. 358] to it, the distinction between souls and bodies being of very early date.

But although extension, impermeability, cohesion, and motion, in fact everything that the external senses can give us, cannot be thoughts, feeling, inclination, and determination, or contain anything like them, being never objects of external intuition, it might be possible, nevertheless, that that something which forms the foundation of external phenomena, and which so affects our sense as to produce in it the representations of space, matter, form, etc., if considered as a noumenon (or better as a transcendental object) might be, at the same time, the subject of thinking, although by the manner in which it affects our external sense it produces in us no intuitions of representations, will, etc., but only of space and its determinations. This something, however, is not extended, not impermeable, not composite, because such predicates concern sensibility only and its intuition, whenever we are affected by these (to us otherwise unknown) objects. These expressions, however, do not give us any information what kind of object it is, but only that, if considered by itself, without reference to the external senses, it has no right to these predicates, peculiar to external appearance. The predicates of the internal sense, on the contrary, such as representation, thinking, [p. 359] etc., are by no means contradictory to it, so that really, even if we admit the simplicity of its nature, the human soul is by no means sufficiently distinguished from matter, so far as its substratum is concerned, if (as it ought to be) matter is considered as a phenomenon only.

If matter were a thing by itself, it would, as a composite being, be totally different from the soul, as a simple being. But what we call matter is an external phenomenon only, the substratum of which cannot possibly be known by any possible predicates. I can therefore very well suppose that that substratum is simple, although in the manner in which it affects our senses it produces in us the intuition of something extended, and therefore composite, so that the substance which, with reference to our external sense, possesses extension, might very well by itself possess thoughts which can be represented consciously by its own internal sense. In such wise the same thing which in one respect is called corporeal, would in another respect be at the same time a thinking being, of which though we cannot see its thoughts, we can yet see the signs of them phenomenally. Thus the expression that souls only (as a particular class of substances) think, would have to be dropt, and we should return to the common expression that men think, that is, [p. 360] that the same thing which, as an external phenomenon, is extended, is internally, by itself, a subject, not composite, but simple and intelligent.

But without indulging in such hypotheses, we may make this general remark, that if I understand by soul a being by itself, the very question would be absurd, whether the soul be homogeneous or not with matter which is not a thing by itself, but only a class of representations within us; for so much at all events must be clear, that a thing by itself is of a different nature from the determinations which constitute its state only.

If, on the contrary, we compare the thinking I, not with matter, but with that object of the intellect that forms the foundation of the external phenomena which we call matter, then it follows, as we know nothing whatever of the matter, that we have no right to say that the soul by itself is different from it in any respect.

The simple consciousness is not therefore a knowledge of the simple nature of our subject, so that we might thus distinguish the soul from matter, as a composite being.

If therefore, in the only case where that concept might be useful, namely, in comparing myself with objects of external experience, it is impossible to determine the peculiar and distinguishing characteristics of its nature, what is the use, if we pretend to know that the [p. 361] thinking I, or the soul (a name for the transcendental object of the internal sense), is simple? Such a proposition admits of no application to any real object, and cannot therefore enlarge our knowledge in the least.

Thus collapses the whole of rational psychology, with its fundamental support, and neither here nor elsewhere can we hope by means of mere concepts (still less through the mere subjective form of all our concepts, that is, through our consciousness) and without referring these concepts to a possible experience, to extend our knowledge, particularly as even the fundamental concept of a simple nature is such that it can never be met with in experience, so that no chance remains of arriving at it as a concept of objective validity.

The Third Paralogism of Personality

Whatever is conscious of the numerical identity of its own self at different times, is in so far a person.

Now the Soul, etc.

Therefore the Soul is a person.

Criticism of the Third Paralogism of Transcendental Psychology

Whenever I want to know by experience the numerical identity of an external object, I shall have to [p. 362] attend to what is permanent in that phenomenon to which, as the subject, everything else refers as determination, and observe the identity of the former during the time that the latter is changing. I myself, however, am an object of the internal sense, and all time is but the form of the internal sense. I therefore refer each and all of my successive determinations to the numerically identical self; and this in all time, that is, in the form of the inner intuition of myself. From this point of view, the personality of the soul should not even be considered as inferred, but as an entirely identical proposition of self-consciousness in time, and that is indeed the reason why it is valid a priori. For it really says no more than this: that during the whole time, while I am conscious of myself, I am conscious of that time as belonging to the unity of myself; and it comes to the same thing whether I say that this whole time is within me as an individual unity, or that I with numerical identity am present in all that time.

In my own consciousness, therefore, the identity of person is inevitably present. But if I consider myself from the point of view of another person (as an object of his external intuition), then that external observer considers me, first of all, in time, for in the apperception time is really represented in me only. Though he admits, therefore, the I, which at all times accompanies all representations in my consciousness, and with [p. 363] entire identity, he will not yet infer from it the objective permanence of myself. For as in that case the time in which the observer places me is not the time of my own, but of his sensibility, it follows that the identity which is connected with my consciousness is not therefore connected with his, that is, with the external intuition of my subject.

The identity of my consciousness at different times is therefore a formal condition only of my thoughts and their coherence, and proves in no way the numerical identity of my subject, in which, in spite of the logical identity of the I, such a change may have passed as to make it impossible to retain its identity, though we may still attribute to it the same name of I, which in every other state, and even in the change of the subject, might yet retain the thought of the preceding and hand it over to the subsequent subject.1

Although the teaching of some old schools [p. 364] that everything is in a flux, and nothing in the world permanent, cannot be admitted, if we admit substances, yet it must not be supposed that it can be refuted by the unity of self-consciousness. For we ourselves cannot judge from our own consciousness whether, as souls, we are permanent or not, because we reckon as belonging to our own identical self that only of which we are conscious, and therefore are constrained to admit that, during the whole time of which we are conscious, we are one and the same. From the point of view of a stranger, however, such a judgment would not be valid, because, perceiving in the soul no permanent phenomena, except the representation of the I, which accompanies and connects them all, we cannot determine whether that I (being a mere thought) be not in the same state of flux as the other thoughts which are chained together by the I. [p. 365]

It is curious, however, that the personality and what is presupposed by it, namely, the permanence and substantiality of the soul, has now to be proved first. For if we could presuppose these, there would follow, if not the permanence of consciousness, yet the possibility of a permanent consciousness in one and the same subject, and this is sufficient to establish personality which does not cease at once, because its effect is interrupted at the time. This permanence, however, is by no means given us before the numerical identity of ourself, which we infer from identical apperception, but is itself inferred from it, so that, according to rule, the concept of substance, which alone is empirically useful, would have to follow first upon it. But as the identity of person follows by no means from the identity of the I, in the consciousness of all time in which I perceive myself, it follows that we could not have founded upon it the substantiality of the soul.

Like the concept of substance and of the simple, however, the concept of personality also may remain, so long as it is used as transcendental only, that is, as a concept of the unity of the subject which is otherwise unknown to us, but in the determinations of which there is an uninterrupted connection by apperception. In this sense such a concept is necessary for practical purposes and sufficient, but we can never pride ourselves on it as helping to expand our knowledge of our self by means of [p. 366] pure reason, which only deceives us if we imagine that we can concluse an uninterrupted continuance of the subject from the mere concept of the identical self. That concept is only constantly turning round itself in a circle, and does not help us as with respect to any question which aims at synthetical knowledge. What matter may be as a thing by itself (a transcendental object) is entirely unknown to us; though we may observe its permanence as a phenomenon, since it is represented as something external. When however I wish to observe the mere I during the change of all representations, I have no other correlative for my comparisons but again the I itself, with the general conditions of my consciousness. I cannot therefore give any but tautological answers to all questions, because I put my concept and its unity in the place of the qualities that belong to me as an object, and thus really take for granted what was wished to be known.

The Fourth Paralogism of Ideality (with Regard to External Relations)

That, the existence of which can only be inferred as a cause of given perceptions, has a doubtful existence only: — [p. 367]

All external phenomena are such that their existence cannot be perceived immediately, but that we can only infer them as the cause of given perceptions: —

Therefore the existence of all objects of the external senses is doubtful. This uncertainty I call the ideality of external phenomena, and the doctrine of that ideality is called idealism; in comparison with which the other doctrine, which maintains a possible certainty of the objects of the external senses, is called dualism.

Criticism of the Fourth Paralogism of Transcendental Psychology

We shall first have to examine the premisses. We are perfectly justified in maintaining that that only which is within ourselves can be perceived immediately, and that my own existence only can be the object of a mere perception. The existence of a real object therefore outside me (taking this word in its intellectual meaning) can never be given directly in perception, but can only be added in thought to the perception, which is a modification of the internal sense, and thus inferred as its external cause. Hence Cartesius was quite right in limiting all perception, in the narrowest sense, to the proposition, I (as a thinking being) am. For it must be clear that, as what [p. 368] is without is not within me, I cannot find it in my apperception; nor hence in any perception which is in reality a determination of apperception only.

In the true sense of the word, therefore, I can never perceive external things, but only from my own internal perception infer their existence, taking the perception as an effect of which something external must be the proximate cause. An inference, however, from a given effect to a definite cause is always uncertain, because the effect may be due to more than one cause. Therefore in referring a perception to its cause, it always remains doubtful whether that cause be internal or external; whether in fact all so-called external perceptions are not a mere play of our external sense, or point to real external objects as their cause. At all events the existence of the latter is inferential only, and liable to all the dangers of inferences, while the object of the internal sense (I myself with all my representations) is perceived immediately, and its existence cannot be questioned.

It must not be supposed, therefore, that an idealist is he who denies the existence of external objects of the senses; all he does is to deny that it is known by immediate perception, and to infer that we can never [p. 369] become perfectly certain of their reality by any experience whatsoever.

Before I expose the deceptive illusion of our paralogism, let me remark that we must necessarily distinguish two kinds of idealism, the transcendental and the empirical. Transcendental idealism teaches that all phenomena are representations only, not things by themselves, and that space and time therefore are only sensuous forms of our intuition, not determinations given independently by themselves or conditions of objects, as things by themselves. Opposed to this transcendental idealism, is a transcendental realism, which considers space and time as something in itself (independent of our sensibility). Thus the transcendental realist represents all external phenomena (admitting their reality) as things by themselves, existing independently of us and our sensibility, and therefore existing outside us also, if regarded according to pure concepts of the understanding. It is this transcendental realist who afterwards acts the empirical idealist, and who, after wrongly supposing that the objects of the senses, if they are to be external, must have an existence by themselves, and without our senses, yet from this point of view considers all our sensuous representations insufficient to render certain the reality of their objects.

The transcendental idealist, on the contrary, [p. 370] may well be an empirical realist, or, as he is called, a dualist; that is, he may admit the existence of matter, without taking a step beyond mere self-consciousness, or admitting more than the certainty of representations within me, that is the cogito, ergo sum. For as he considers matter, and even its internal possibility, as a phenomenon only, which, if separated from our sensibility, is nothing, matter with him is only a class of representations (intuition) which are called external, not as if they referred to objects external by themselves, but because they refer perceptions to space, in which everything is outside everything else, while space itself is inside us.

We have declared ourselves from the very beginning in favour of this transcendental idealism. In our system, therefore, we need not hesitate to admit the existence of matter on the testimony of mere self-consciousness, and to consider it as established by it (i.e. the testimony), in the same manner as the existence of myself, as a thinking being. I am conscious of my representations, and hence they exist as well as I myself, who has these representations. External objects, however (bodies), are phenomena only, therefore nothing but a class of my representations, the objects of which are something by means of these representations only, and apart from them nothing. [p. 371] External things, therefore, exist by the same right as I myself, both on the immediate testimony of my self-consciousness, with this difference only, that the representation of myself, as a thinking subject, is referred to the internal sense only, while the representations which indicate extended beings are referred to the external sense also. With reference to the reality of external objects, I need as little trust to inference, as with reference to the reality of the object of my internal sense (my thoughts), both being nothing but representations, the immediate perception (consciousness) of which is at the same time a sufficient proof of their reality.

The transcendental idealist is, therefore, an empirical realist, and allows to matter, as a phenomenon, a reality which need not be inferred, but may be immediately perceived. The transcendental realism, on the contrary, is necessarily left in doubt, and obliged to give way to empirical idealism, because it considers the objects of the external senses as something different from the senses themselves, taking mere phenomena as independent beings, existing outside us. And while with the very best consciousness of our representation of these things, it is far from certain that, if a representation exists, its corresponding object must exist also, it is clear that in our system external things, that is, matter in all its shapes and changes, are nothing but mere phenomena, [p. 372] that is, representations within us, of the reality of which we are immediately conscious.

As, so far as I know, all psychologists who believe in empirical idealism are transcendental realists, they have acted no doubt quite consistently, in ascribing great importance to empirical idealism, as one of the problems from which human reason could hardly extricate itself. For indeed, if we consider external phenomena as representations produced inside us by their objects, as existing as things by themselves outside us, it is difficult to see how their existence could be known otherwise but through a syllogism from effect to cause, where it must always remain doubtful, whether the cause be within or without us. Now we may well admit that something which, taken transcendentally, is outside us, may be the cause of our external intuitions, but this can never be the object which we mean by the representations of matter and material things; for these are phenomena only, that is, certain kinds of representations existing always within us, and the reality of which depends on our immediate consciousness, quite as much as the consciousness of my own thoughts. The transcendental object is unknown equally in regard to internal and external intuition.

Of this, however, we are not speaking at [p. 373] present, but only of the empirical object, which is called external, if represented in space, and internal, when represented in temporal relations only, both space and time being to be met with nowhere except in ourselves.

The expression, outside us, involves however an inevitable ambiguity, because it may signify either, something which, as a thing by itself, exists apart from us, or what belongs to outward appearance only. In order, therefore, to remove all uncertainty from that concept, taken in the latter meaning (which alone affects the psychological question as to the reality of our external intuition) we shall distinguish empirically external objects from those that may be called so in a transcendental sense, by calling the former simply things occurring in space.

Space and time are no doubt representations a priori, which dwell in us as forms of our sensuous intuition, before any real object has determined our senses by means of sensation, enabling them to represent the object under those sensuous conditions. But this something, material or real, that is to be seen in space, presupposes necessarily perception, and cannot be fancied or produced by means of imagination without that perception, which indicates the reality of something in space. It is sensation, therefore, that indicates reality [p. 374] in space and time, according as it is related to the one or the other mode of sensuous intuition. If sensation is once given (which, if referring to an object in general, and not specialising it, is called perception), many an object may be put together in imagination from the manifold materials of perception, which has no empirical place in space or time, but in imagination only. This admits of no doubt, whether we take the sensations of pain and pleasure, or the external ones of colour, heat, etc.; it is always perception by which the material for thinking of any objects of external intuition must be first supplied. This perception, therefore (to speak at present of external intuitions only), represents something real in space. For, first, perception is the representation of a reality, while space is the representation of a mere possibility of coexistence. Secondly, this reality is represented before the external sense, that is, in space. Thirdly, space itself is nothing but mere representation, so that nothing in it can be taken as real, except what is represented in it;1 or, vice versa, whatever is given in it, that is, whatever [p. 375] is represented in it by perception, is also real in it, because, if it were not real in it, that is, given immediately by empirical intuition, it could not be created by fancy, the real of intuition being unimaginable a priori.

Thus we see that all external perception proves immediately something real in space, or rather is that real itself. Empirical realism is therefore perfectly true, that is, something real in space always corresponds to our external intuitions. Space itself, it is true, with all its phenomena, as representations, exists within me only, but the real or the material of all objects of intuition is nevertheless given in that space, independent of all fancy or imagination; nay, it is impossible that in that space anything outside us (in a transcendental sense) could be given, because space itself is nothing outside our sensibility. The strictest idealist, therefore, can never require that we should prove that the object without us [p. 376] (in its true meaning) corresponds to our perception. For granted there are such objects, they could never be represented and seen, as outside us, because this presupposes space, and the reality in space, as a mere representation, is nothing but the perception itself. It thus follows, that what is real in external phenomena, is real in perception only, and cannot be given in any other way.

From such perceptions, whether by mere play of fancy or by experience, knowledge of objects can be produced, and here no doubt deceptive representations may arise, without truly corresponding objects, the deception being due, either to illusions of imagination (in dreams), or to a fault of judgment (the so-called deceptions of the senses). In order to escape from these false appearances, one has to follow the rule that, whatever is connected according to empirical laws with a perception, is real. This kind of illusion, however, and its prevention, concerns idealism as well as dualism, since it affects the form of experience only. In order to refute empirical idealism and its unfounded misgivings as to the objective reality of our external perceptions, it is sufficient to consider 1) that external perception proves immediately a reality in space, which space, though in itself a mere form of [p. 377] representations, possesses nevertheless objective reality with respect to all external phenomena (which themselves are mere representations only); 2) that without perception, even the creations of fancy and dreams would not be possible, so that our external senses, with reference to the data from which experience can spring, must have real objects corresponding to them in space.

There are two kinds of idealists, the dogmatic, who denies the existence of matter, and the sceptical, who doubts it, because he thinks it impossible to prove it. At present we have nothing to do with the former, who is an idealist, because he imagines he finds contradictions in the possibility of matter in general. This is a difficulty which we shall have to deal with in the following section on dialectical syllogisms, treating of reason in its internal struggle with reference to the concepts of the possibility of all that belongs to the connection of experience. The sceptical idealist, on the contrary, who attacks only the ground of our assertion, and declares our conviction of the existence of matter, which we founded on immediate perception, as insufficient, is in reality a benefactor of human reason, because he obliges us, even in the smallest matter of common experience, to keep our eyes well [p. 378] open, and not to consider as a well-earned possession what may have come to us by mistake only. We now shall learn to understand the great advantage of these idealistic objections. They drive us by main force, unless we mean to contradict ourselves in our most ordinary propositions, to consider all perceptions, whether we call them internal or external, as a consciousness only of what affects our sensibility, and to look on the external objects of them, not as things by themselves, but only as representations of which, as of every other representation, we can become immediately conscious, and which are called external, because they depend on what we call the external sense with its intuition of space, space being itself nothing but an internal kind of representation in which certain perceptions become associated.

If we were to admit external objects to be things by themselves, it would be simply impossible to understand how we can arrive at a knowledge of their reality outside us, considering that we always depend on representations which are inside us. It is surely impossible that we should feel outside us, and not inside us, and the whole of our self-consciousness cannot give us anything but our own determinations. Thus sceptical idealism forces us to take refuge in the only place that is left to us, namely, in the ideality of all phenomena: the very ideality which, though as yet unprepared for its consequences, we established in our own transcendental Æsthetic. If [p. 379] then we ask whether, consequently, dualism only must be admitted in psychology, we answer, certainly, but only in its empirical acceptation. In the connection of experience matter, as the substance of phenomena, is really given to the external sense in the same manner as the thinking I, likewise as the substance of phenomena, is given to the internal sense; and it is according to the rules which this category introduces into the empirical connection of our external as well as internal perceptions, that phenomena on both sides must be connected among themselves. If, on the contrary, as often happens, we were to extend the concept of dualism and take it in its transcendental acceptation, then neither it, nor on one side the pneumatism, or on the other side the materialism, which are opposed to dualism, would have the smallest foundation; we should have missed the determination of our concepts, and have mistaken the difference in our mode of representing objects, which, with regard to what they are in themselves, remain always unknown to us, for a difference of the things themselves. No doubt I, as represented by the internal sense in time, and objects in space outside me, are two specifically different phenomena, but they are not therefore conceived as different things. The transcendental object, which forms the foundation of external phenomena, and the other, which forms the foundation of our internal intuition, is therefore [p. 380] neither matter, nor a thinking being by itself, but simply an unknown cause of phenomena which supply to us the empirical concept of both.

If therefore, as evidently forced to do by this very criticism, we remain faithful to the old rule, never to push questions beyond where possible experience can supply us with an object, we shall never dream of going beyond the objects of our senses and asking what they may be by themselves, that is, without any reference to our senses. But if the psychologist likes to take phenomena for things by themselves, then, whether he admit into his system, as a materialist, matter only, or, as a spiritualist, thinking beings only (according to the form of our own internal sense), or, as a dualist, both, as things existing in themselves, he will always be driven by his mistake to invent theories as to how that which is not a thing by itself, but a phenomenon only, could exist by itself.

CONSIDERATION

on the Whole of Pure Psychology, as affected by these Paralogisms[p. 381]

If we compare the science of the soul, as the physiology of the internal sense, with the science of the body, as a physiology of the objects of external senses, we find, besides many things which in both must be known empirically, this important difference, that in the latter many things can be known a priori from the mere concept of an extended and impermeable being, while in the former nothing can be known a priori and synthetically from the concept of a thinking being. The cause is this. Though both are phenomena, yet the phenomena of the external sense have something permanent, which suggests a substratum of varying determinations, and consequently a synthetical concept, namely, that of space, and of a phenomenon in space; while time, the only form of our internal intuition, has nothing permanent, and makes us to know the change of determinations only, but not the determinable object. For in what we call soul there is a continuous flux, and nothing permanent, except it may be (if people will so have it) the simple I, so simple because this representation has no contents, consequently nothing manifold, so that it seems to represent, or more accurately to indicate, a simple [p. 382] object. This I or Ego would have to be an intuition, which, being presupposed in all thought (before all experience), might as an intuition a priori supply synthetical propositions, if it should be possible to get any knowledge by pure reason of the nature of a thinking being in general. But this I is neither an intuition nor a concept of any object, but the mere form of consciousness which can accompany both classes of representations, and impart to them the character of knowledge, provided something else be given in intuition which supplies matter for a representation of an object. Thus we see that the whole of rational psychology is impossible as transcending the powers of human reason, and nothing remains to us but to study our soul under the guidance of experience, and to keep ourselves within the limits of questions which do not go beyond the line where the material can be supplied by possible internal experience.

But although rational psychology is of no use in extending our knowledge, but as such is made up of paralogisms only, we cannot deny to it an important negative utility, if it does not pretend to be more than a critical investigation of our dialectical syllogisms, as framed by our common and natural reason.

What purpose can be served by psychology [p. 383] founded on pure principles of reason? Its chief purpose is meant to be to guard our thinking self against the danger of materialism. This purpose however is answered, as we have shown, by the concept which reason gives of our thinking self. For, so far from there being any fear lest, if matter be taken away, all thought, and even the existence of thinking beings might vanish, it has been on the contrary clearly shown that, if we take away the thinking subject, the whole material world would vanish, because it is nothing but a phenomenon in the sensibility of our own subject, and a certain class of its representations.

It is true that I do not know thus this thinking self any better according to its qualities, nor can I perceive its permanence, or even the independence of its existence from the problematical transcendental substratum of external phenomena, both being necessarily unknown to us. But as it is nevertheless possible that I may find reason, from other than purely speculative causes, to hope for an independent, and, during every possible change of my states, permanently abiding existence of my thinking nature, much is gained if, though I freely confess my own ignorance, I can nevertheless repel the dogmatical attacks of a speculative opponent, [p. 384] showing to him that he can never know more of the nature of the subject, in order to deny the possibility of my expectations, than I can know, in order to cling to them.

Three dialectical questions, which form the real object of all rational psychology, are founded on this transcendental illusion of our psychological concepts, and cannot be answered except by means of the considerations in which we have just been engaged, namely, (1) the question of the possibility of the association of the soul with an organic body, that is, of animality and the state of the soul in the life of man; (2) the question of the beginning of that association of the soul at the time and before the time of our birth; (3) the question of the end of that association of the soul at and after the time of death (immortality).

What I maintain is, that all the difficulties which we imagine to exist in these questions, and with which, as dogmatical objections, people wish to give themselves an air of deeper insight into the nature of things than the common understanding can ever claim, rest on a mere illusion, which leads us to hypostasise what exists in thought only, and to accept it in the same quality in which it is thought as a real object, outside the thinking subject, taking in fact extension, which is phenomenal only, for a quality of external things, existing [p. 385] without our sensibility also, and movement as their effect, taking place by itself also, and independently of our senses. For matter, the association of which with the soul causes so much misgiving, is nothing but a mere orm, or a certain mode of representing an unknown object by that intuition which we call the external sense. There may, therefore, well be something outside us to which the phenomenon which we call matter corresponds; though in its quality of phenomenon it cannot be outside us, but merely as a thought within us, although that thought represents it through the external sense as existing outside us. Matter, therefore, does not signify a class of substances totally heterogeneous and different from the object of the internal sense (the soul), but only the different nature of the phenomenal appearance of objects (in themselves unknown to us), the representations of which we call external, as compared with those which we assign to the internal sense, although, like other thoughts, those external representations also belong to the thinking subject only. They possess however this illusion that, as they represent objects in space, they seem to separate themselves from the soul and to move outside it, although even the space, in which they are seen, is nothing but a representation of which no homogeneous original can ever be found outside the soul. The question therefore is no longer as to the possibility of an association of the soul with other known and foreign [p. 386] substances outside us, but only as to the connection of the representations of the internal sense with the modifications of our external sensibility, and how these can be connected with each other according to constant laws, and acquire cohesion in experience.

So long as we connect internal and external phenomena with each other as mere representations in our experience, there is nothing irrational, nor anything to make the association of both senses to appear strange. As soon however as we hypostatise the external phenomena, looking upon them no longer as representations, but as things existing by themselves and outside us, with the same quality in which they exist inside us, and referring to our own thinking subject their acts which they, as phenomena, show in their mutual relation, the effective causes outside us assume a character which will not harmonise with their effects within us, because that character refers to the external senses only, but the effects to the internal sense, both being entirely unhomogeneous, though united in the same subject. We then have no other external effects but changes of place, and no forces but tendencies, which have for their effects relations in space only. Within us, on the contrary, those effects are mere thoughts, without any relations of space, movement, shape, or local [p. 387] determination between them; and we entirely lose the thread of the causes in the effects which ought to show themselves in the internal sense. We ought to consider therefore that bodies are not objects by themselves which are present to us, but a mere appearance of we do not know what unknown object, and that movement likewise is not the effect of that unknown cause, but only the appearance of its influence on our senses. Both are not something outside us, but only representation within us, and consequently it is not the movement of matter which produces representations within us, but that motion itself (and matter also, which makes itself known through it) is representation only. Our whole self-created difficulty turns on this, how and why the representations of our sensibility are so connected with each other that those which we call external intuitions can, according to empirical laws, be represented as objects outside us; a question which is entirely free from the imagined difficulty of explaining the origin of our representations from totally heterogeneous efficient causes, existing outside us, the confusion arising from our mistaking the phenomenal appearance of an unknown cause for the very cause outside us. In judgments in which there is a misapprehension confirmed by long habit, it is impossible to bring its correction at once to that clearness which can be [p. 388] produced in other cases, where no inevitable illusion confuses our concept. Our attempt therefore at freeing reason from these sophistical theories can hardly claim as yet that perspicuity which would render it perfectly satisfactory. I hope however to arrive at greater lucidity in the following manner.

All objections may be divided into dogmatical, critical, and sceptical. The dogmatical attacks the proposition, the critical the proof of a proposition. The former presupposes an insight into the peculiar nature of the object in order to be able to assert the contrary of what the proposition asserts. It is therefore itself dogmatical, and pretends to know the peculiar nature of the object in question better than the opponent. The critical objection, as it says nothing about the worth or worthlessness of the proposition, and attacks the proof only, need not know the object itself better, or claim a better knowledge of it. All it wants to show is, that a proposition is not well grounded, not that it is false. The sceptical objection, lastly, places assertion and denial side by side, as of equal value, taking one or the other now as dogma, and now as denial; and being thus in appearance dogmatical on both sides, it renders every judgment [p. 389] on the object impossible. Both the dogmatical and sceptical objections must pretend to so much knowledge of their object as is necessary in order to assert or deny anything about it. The critical objection, on the contrary, wishes only to show that something purely futile and fanciful has been used in support of a proposition, and thus upsets a theory by depriving it of its pretended foundation, without wishing to establish itself anything else about the nature of the object.

According to the ordinary concepts of our reason with regard to the association between our thinking subject and the things outside us, we are dogmatical, and look upon them as real objects, existing independently of ourselves, in accordance with a certain transcendental dualism which does not reckon external phenomena as representations belonging to the subject, but places them, as they are given us in sensuous intuition, as objects outside us and entirely separated from the thinking subject. This mere assumption is the foundation of all theories on the association between soul and body. It is never asked whether this objective reality of phenomena is absolutely true, but it is taken for granted, and the only question seems to be, how it is to be explained and understood. The three systems which are commonly suggested, [p. 390] and which in fact are alone possible, are those, 1st, of physical influence, 2nd, of pre-established harmony, and 3rd, of supernatural assistance.

The second and third explanations of the association between soul and matter arise from objections to the first, which is that of the ordinary understanding, the objection being, that what appears as matter cannot by its immediate influence be the cause of representations, these being a totally heterogeneous class of effects. Those who start this objection cannot understand by the objects of the external senses matter, conceived as phenomenon only, and therefore itself a mere representation produced by whatever external objects. For in that case they would really say that the representations of external objects (phenomena) cannot be the external causes of the representations in our mind, which would be a meaningless objection, because nobody would think of taking for an external cause what he knows to be a mere representation. According to our principles the object of their theory can only be, that that which is the true (transcendental) object of our external senses cannot be the cause of those representations (phenomena) which we mean by the name of matter. As no one has any right to say that he [p. 391] knows anything of the transcendental cause of the representations of our external senses, their assertion is entirely groundless. And if the pretended reformers of the doctrine of physical influence represent, according to the ordinary views of transcendental dualism, matter, as such, as a thing by itself (not simply as a mere phenomenal appearance of an unknown thing), and then proceed in their objections to show that such an external object, which shows no causality but that of movements, can never be the efficient cause of representations, but that a third being must intervene in order to produce, if not reciprocal action, at least correspondence and harmony between the two, they would really begin their refutation by admitting in their dualism the πρωˆτον ψενˆδος of a physical influence, and thus refute by their objection, not so much the physical influence as their own dualistic premisses. For all the difficulties with regard to a possible connection between a thinking nature and matter arise, without exception, from that too readily admitted dualistic representation, namely, that matter, as such, is not phenomenal, that is, a mere representation of the mind to which an unknown object corresponds, but the object itself, such as it exists outside us, and independent of all sensibility. [p. 392]

It is impossible, therefore, to start a dogmatical objection against the commonly received theory of a physical influence. For if the opponent were to say that matter and its movements are purely phenomenal and therefore mere representations, the only difficulty remaining to him would be that the unknown object of our senses could not be the cause of our representations, and this he has no right to say, because no one is able to determine what an unknown object may or may not be able to effect; and, according to our former arguments, he must necessarily admit this transcendental idealism, unless he wishes to hypostasise mere representations and place them outside himself as real things.

What is quite possible, however, is to raise a well-founded critical objection to the commonly received opinion of a physical influence. For the pretended association between two kinds of substances, the one thinking, the other extended, rests on a coarse dualism, and changes the latter, though they are nothing but representations of the thinking subject, into things existing by themselves. Thus the misunderstood physical influence may be entirely upset by showing that the proof which was to establish it, was surreptitiously obtained, and therefore, valueless.

The notorious problem, therefore, as to a possible association between the thinking and the extended, would, when all that is purely imaginative is deducted, [p. 393] come to this, how external intuition, namely, that of space (or what fills space, namely, form and movement), is possible in any thinking subject? To this question, however, no human being can return an answer, and instead of attempting to fill this gap in our knowledge, all we can do is to indicate it by ascribing external phenomena to a transcendental object as the cause of this class of representations, but which we shall never know, nor be able to form any concept of. In all practical questions we treat phenomena as objects by themselves, without troubling ourselves about the first cause of their possibility (as phenomena). But as soon as we go beyond, the concept of a transcendental object becomes inevitable.

The decision of all the discussions on the state of a thinking being, before this association with matter (life) or after the ceasing of such association (death), depends on the remarks which we have just made on the association between the thinking and the extended. The opinion that the thinking subject was able to think before any association with bodies, would assume the following form, that before the beginning of that kind of sensibility [p. 394] through which something appears to us in space, the same transcendental objects, which in our present state appear as bodies, could have been seen in a totally different way. The other opinion that, after the cessation of its association with the material world, the soul could continue to think, would be expressed as follows: that, if that kind of sensibility through which transcendental and, for the present, entirely unknown objects appear to us as a material world, should cease, it would not follow that thereby all intuition of them would be removed: it being quite possible that the same unknown objects should continue to be known by the thinking subject, although no longer in the quality of bodies.

Now it is quite true that no one can produce from speculative principles the smallest ground for such an assertion, or do more than presuppose its possibility, but neither can any valid dogmatical objection be raised against it. For whoever would attempt to do so, would know neither more nor less than I myself, or anybody else, about the absolute and internal cause of external and material phenomena. As he cannot pretend to know on what the reality of external phenomena in our present state (in life) really rests, neither can he know that the condition of all external intuition, or the thinking subject itself, will cease after this state (in death). [p. 395]

We thus see that all the wrangling about the nature of a thinking being, and its association with the material world, arises simply from our filling the gap, due to our ignorance, with paralogisms of reason, and by changing thoughts into things and hypostasising them. On this an imaginary science is built up, both by those who assert and by those who deny, some pretending to know about objects of which no human being has any conception, while others make their own representations to be objects, all turning round in a constant circle of ambiguities and contradictions. Nothing but a sober, strict, and just criticism can free us of this dogmatical illusion, which, through theories and systems, deceives so many by an imaginary happiness. It alone can limit our speculative pretensions to the sphere of possible experience, and this not by a shallow scoffing at repeated failures or by pious sighs over the limits of our reason, but by a demarcation made according to well-established principles, writing the nihil ulterius with perfect assurance on those Herculean columns which Nature herself has erected, in order that the voyage of our reason should be continued so far only as the continuous shores of experience extend — shores which we can never forsake without [p. 396] being driven upon a boundless ocean, which, after deceiving us again and again, makes us in the end cease all our laborious and tedious endeavours as perfectly hopeless.

*     *     *     *     *     *     *     *

We have yet to give a general and clear investigation of the transcendental, and yet natural illusion, produced by the paralogisms of pure reason, and the justification of our systematical arrangement of them, which ran parallel with the table of the categories. We could not have done this at the beginning of this section, without running the risk of becoming obscure, or inconveniently anticipating our arguments. We shall now try to fulfil our duty.

All illusion may be explained as mistaking the subjective condition of thought for the knowledge of the object. In the introduction to the transcendental Dialectic, we showed that pure reason is occupied exclusively with the totality of the synthesis of conditions belonging to anything conditioned. Now as the dialectical illusion of pure reason cannot be an empirical illusion, such as occurs in certain empirical kinds of knowledge, it can refer only to the conditions of thought in general, so that there can [p. 397] only be three cases of the dialectical use of pure reason:—

1. The synthesis of the conditions of a thought in general.

2. The synthesis of the conditions of empirical thought.

3. The synthesis of the conditions of pure thought.

In every one of these three cases pure reason is occupied only with the absolute totality of that synthesis, that is, with that condition, which is itself unconditioned. It is on this division also that the threefold transcendental illusion is founded which leads to three subdivisions of the Dialectic, and to as many pretended sciences flowing from pure reason, namely, transcendental psychology, cosmology, and theology. We are at present concerned with the first only.

As, in thinking in general, we take no account of the relation of our thoughts to any object (whether of the senses or of the pure understanding), what is called (1) the synthesis of the conditions of a thought in general, is not objective at all, but only a synthesis of thought with the subject, which synthesis is wrongly taken for the synthetical representation of an object.

It follows from this that the dialectical conclusion as to the condition of all thought in general, which condition itself is unconditioned, does not involve a fault in its contents (for it ignores all contents or objects), but only a fault in form, and must therefore be called a [p. 398] paralogism.

As, moreover, the only condition which accompanies all thought is the I, in the general proposition I think, reason has really to deal with this condition, so far as that condition is itself unconditioned. It is however a formal condition only, namely, the logical unity of every thought, no account being taken of any object; but it is represented nevertheless as an object which I think, namely, as the I itself and its unconditioned unity.

If I were asked what is the nature of a thing which thinks, I could not give any answer a priori, for the answer ought to be synthetical, as an analytical answer might explain perhaps the meaning of the term “thought,” but could never add any real knowledge of that on which the possibility of thought depends. For a synthetical solution, however, we should require intuition, and this has been entirely left out of account in the general form given to our problem. It is equally impossible to answer the general question, what is the nature of a thing which is moveable, because in that case the impermeable extension (matter) is not given. But although I have no answer to return to that question in general, it might seem that I could answer it in a special case, namely, in the proposition which expresses the self-consciousness, I think. For this I is the first subject, i.e. substance, [p. 399] it is simple, etc. These, however, ought then to be propositions of experience, which nevertheless, without a general rule containing the conditions of the possibility of thought in general and a priori, could not contain such predicates (which are not empirical). This consideration makes our knowledge of the nature of a thinking being derived from pure concepts, which seemed at first so plausible, extremely suspicious, though we have not yet discovered the place where the fault really lies.

A further investigation, however, of the origin of the attributes which I predicate of myself as a thinking being in general, may help us to discover the fault. They are no more than pure categories by which I can never think a definite object, but only the unity of the representations which is requisite in order to determine an object. Without a previous intuition, no category by itself can give me a concept of an object, for by intuition alone the object is given, which afterwards is thought in accordance with a category. In order to declare a thing to be a substance in phenomenal appearance, predicates of its intuition must first be given to me, in which I may distinguish the permanent from the changeable, and the substratum (the thing in itself) from that which is merely inherent [p. 400] in it. If I call a thing simple as a phenomenon, what I mean is that its intuition is a part of phenomenal appearance, but cannot itself be divided into parts, etc. But if I know something to be simple by a concept only, and not by phenomenal appearance, I have really no knowledge whatever of the object, but only of my concept which I make to myself of something in general, that is incapable of any real intuition. I only say that I think something as perfectly simple, because I have really nothing to say of it except that it is something.

Now the mere apperception (the I) is substance in concept, simple in concept, etc., and so far all the psychological propositions of which we spoke before are incontestably true. Nevertheless what we really wish to know of the soul, becomes by no means known to us in that way, because all those predicates are with regard to intuition non-valid, entailing no consequences with regard to objects of experience, and therefore entirely empty. For that concept of substance does not teach me that the soul continues by itself, or that it is a part of external intuitions, which itself cannot be resolved into parts, and cannot therefore arise or perish by any changes of nature. These are qualities which would make the soul known to us in its connection with experience, and might give us an insight into its origin and future state. But [p. 401] if I say, by means of the category only, that the soul is a simple substance, it is clear that the bare rational concept of substance contains nothing beyond the thought that a thing should be represented as a subject in itself, without becoming in turn a predicate of anything else. Nothing can be deduced from this, with regard to the permanence (of the I), nor can the attribute of simplicity add that of permanence, nor can we thus learn anything whatsoever as to the fate of the soul in the revolutions of the world. If anybody could tell us that the soul is a simple part of matter, we might, with the help of experience, deduce from this the permanence and, on account of its simple nature, the indestructibility of the soul. But of all this, the concept of the I, in the psychological proposition of I think, tells us nothing.

The reason why that being which thinks within us imagines that it knows itself by means of pure categories, and especially by that which expresses absolute unity under each head, is this. The apperception itself is the ground of the possibility of the categories, and these represent nothing but the synthesis of the manifold in intuition, so far as it has unity in apperception. Self-consciousness therefore is the representation of that which forms the condition of all unity, and is itself unconditioned. One may therefore say of the thinking [p. 402] I (the soul), which represents itself as substance, simple, numerically identical in all time, and as the correlative of all existence, from which in fact all other existence must be concluded, that it does not know itself through the categories, but knows the categories only, and through them all objects, in the absolute unity of apperception, that is, through itself. It may seem no doubt self-evident that I cannot know as an object that which is presupposed in order to enable me to know an object, and that the determining self (thought) differs from the self that is to be determined (the thinking subject), like knowledge from its object. Nevertheless nothing is more natural or at least more tempting than the illusion which makes us look upon the unity in the synthesis of thoughts as a perceived unity in the subject of thoughts. One might call it the surreptitious admission of an hypostasised consciousness (apperceptionis substantiatae).

If we want to have a logical term for the paralogism in the dialectical syllogisms of rational psychology, based on perfectly correct premisses, it might be called a sophisma figurae dictionis. In the major we use the category, with reference to its condition, transcendentally only; in the minor and in the conclusion, we use the same category, with reference to the soul which is to be comprehended [p. 403] under that condition, empirically. Thus, in the paralogism of substantiality,1 the concept of substance is a purely intellectual concept which, without the conditions of sensuous intuition, admits of a transcendental use only, that is, of no use at all. In the minor, however, we refer the same concept to the object of all internal experience, though without having previously established the condition of its application in concreto, namely, its permanence. We thus are making an empirical, and therefore entirely inadmissible use of it.

Lastly, in order to show the systematical connection of all these dialectical propositions of a rationalising psychology, according to their connection in pure reason, and thus to establish their completeness, it should be remarked that the apperception is carried through all the classes of the categories, but only with reference to those concepts of the understanding, which in each of them formed a foundation of unity for the others in a possible perception, namely subsistence, reality, unity (not plurality), and existence, all of which are here represented by reason, as conditions (themselves unconditioned) of the possibility of a thinking being. Thus the soul knows in itself: —

Reason is the faculty of principles. The statements [p. 405] of pure psychology do not contain empirical predicates of the soul, but such as, if they exist, are meant to determine the object by itself, independent of all experience, and therefore by a pure reason only. They ought therefore to rest on principles and on general concepts of thinking beings. Instead of this we find that a single representation, I think,1 governs them all, a representation which, for the very reason that it expresses the pure formula of all my experience (indefinitely), claims to be a general proposition, applicable to all thinking beings, and, though single in all respects, has the appearance of an absolute unity of the conditions of thought in general, thus stretching far beyond the limits of possible experience.]

CHAPTER II

THE ANTINOMY OF PURE REASON

In the Introduction to this part of our work we showed that all the transcendental illusion of pure reason depended on three dialectical syllogisms, the outline of which is supplied to us by logic in the three formal kinds of the ordinary syllogism, in about the same way in which the logical outline of the categories was derived from the [p. 406] four functions of all judgments. The first class of these rationalising syllogisms aimed at the unconditioned unity of the subjective conditions of all representations (of the subject or the soul) as corresponding to the categorical syllogisms of reason, the major of which, as the principle, asserts the relation of a predicate to a subject. The second class of the dialectical arguments will, therefore, in analogy with the hypothetical syllogisms, take for its object the unconditioned unity of the objective conditions in phenomenal appearance, while the third class, which has to be treated in the following chapter, will be concerned with the unconditioned unity of the objective conditions of the possibility of objects in general.

It is strange, however, that a transcendental paralogism caused a one-sided illusion only, with regard to our idea of the subject of our thought; and that it is impossible to find in mere concepts of reason the slightest excuse for maintaining the contrary. All the advantage is on the side of pneumatism, although it cannot hide the hereditary taint by which it evaporates into nought, when subjected to the ordeal of our critique.

The case is totally different when we apply reason to the objective synthesis of phenomena; here reason tries at first, with great plausibility, to establish its principle [p. 407] of unconditioned unity, but becomes soon entangled in so many contradictions, that it must give up its pretensions with regard to cosmology also.

For here we are met by a new phenomenon in human reason, namely, a perfectly natural Antithetic, which is not produced by any artificial efforts, but into which reason falls by itself, and inevitably. Reason is no doubt preserved thereby from the slumber of an imaginary conviction, which is often produced by a purely one-sided illusion; but it is tempted at the same time, either to abandon itself to sceptical despair, or to assume a dogmatical obstinacy, taking its stand on certain assertions, without granting a hearing and doing justice to the arguments of the opponent. In both cases, a death-blow is dealt to sound philosophy, although in the former we might speak of the Euthanasia of pure reason.

Before showing the scenes of discord and confusion produced by the conflict of the laws (antinomy) of pure reason, we shall have to make a few remarks in order to explain and justify the method which we mean to follow in the treatment of this subject. I shall call all transcendental ideas, so far as they relate to the absolute totality in the synthesis of phenomena, cosmical concepts, [p. 408] partly, because of even this unconditioned totality on which the concept of the cosmical universe also rests (which is itself an idea only), partly, because they refer to the synthesis of phenomena only, which is empirical, while the absolute totality in the synthesis of the conditions of all possible things must produce an ideal of pure reason, totally different from the cosmical concept, although in a certain sense related to it. As therefore the paralogisms of pure reason formed the foundation for a dialectical psychology, the antinomy of pure reason will place before our eyes the transcendental principles of a pretended pure (rational) cosmology, not in order to show that it is valid and can be accepted, but, as may be guessed from the very name of the antinomy of reason, in order to expose it as an idea surrounded by deceptive and false appearances, and utterly irreconcileable with phenomena.

[1 ]Here the same as transcendent.

[1 ]I have adopted Erdmann’s conjecture, als solche Begriffe instead of aus solchen Begriffen.

[1 ]See Supplement XXI.

[2 ]Insert man before gleichwohl, and leave out können at the end of the sentence.

[1 ]Read seine Ursache instead of ihre.

[1 ]No doubt by reality I assert more than by possibility, but not in the thing itself, which can never contain more in its reality than what is contained in its complete possibility. While possibility is only the positing of a thing in reference to the understanding (in its empirical use), reality is, at the same time, a connection of it with perception.

[1 ]See Supplement XXII.

[1 ]Additions of the Second Edition.

[1 ]I am treating here of the real definition, which not only puts in place of the name of a thing other and more intelligible words, but that which contains a clear mark by which the object (definitum) can at all times be safely recognised, and by which the defined concept becomes fit for practical use. A real definition (Realarklärung) must therefore render clear the concept itself, and its objective reality also. Of this kind are the mathematical explanations which represent an object in intuition, according to its concept.

[2 ]Read nimmt instead of nehmen, and können instead of könne.

[1 ]The passage from ‘It seems to be’ to ‘objective concepts’ is left out in the Second Edition, and replaced by a short note, see Supplement XXIII.

[1 ]The passage from ‘Appearances’ to ‘given to me in intuition’ is left out in the Second Edition, and replaced by Supplement XXIV.

[1 ]Read welches instead of welcher.

[1 ]Addition of the Second Edition.

[1 ]An additional note in the Second Edition is given in Supplement XXV.

[1 ]Sensibility, if subjected to the understanding as the object on which it exercises its function, is the source of real knowledge, but sensibility, if it influences the action of the understanding itself and leads it on to a judgment, is the cause of error.

[1 ]It is true, however, that he extended his concept of ideas to speculative knowledge also, if only it was pure, and given entirely a priori. He extended it even to mathematics, although they can have their object nowhere but in possible experience. In this I cannot follow him, nor in the mystical deduction of his ideas, and in the exaggerations which led him, as it were, to hypostasise them, although the high-flown language which he used, when treating of this subject, may well admit of a milder interpretation, and one more in accordance with the nature of things.

[1 ]Instead of Anleitung read Ableitung.

[1 ]See Supplement XXVI.

[1 ]Transcendent is a misprint.

[1 ]All that follows from here to the beginning of the second chapter, is left out in the Second Edition, and replaced by Supplement XXVII.

[2 ]Afterwards transcendental instead of pure.

[1 ]It would be very easy to give to this argument the ordinary scholastic dress. But for my purposes it is sufficient to have clearly exhibited, even in a popular form, the ground on which it rests.

[1 ]An elastic ball, which impinges on another in a straight line, communicates to it its whole motion, and therefore (if we only consider the places in space) its whole state. If then, in analogy with such bodies, we admit substances of which the one communicates to the other representations with consciousness, we could imagine a whole series of them, in which the first communicates its state and its consciousness to the second, the second its own state with that of the first substance to a third, and this again all the states of the former, together with its own, and a consciousness of them, to another. That last substance would be conscious of all the states of the previously changed substances, as of its own, because all of them had been transferred to it with the consciousness of them; but for all that it would not have been the same person in all those states.

[1 ]We must well master this paradoxical, but quite correct proposition, that nothing can be in space, except what is represented in it. For space itself is nothing but representation, and whatever is in it must therefore be contained in that representation. There is nothing whatever in space, except so far as it is really represented in it. That a thing can exist only in the representation of it, may no doubt sound strange; but will lose its strangeness if we consider that the things with which we have to deal, are not things by themselves, but phenomena only, that is, representations.

[1 ]Simplicität was a misprint for substantialität.

[1 ]Ich bin was a mistake, it can only be meant for Ich denke.