(Analytic of Concepts)
P 092 TRANSCENDENTAL DOCTRINE OF ELEMENTS SECOND PART TRANSCENDENTAL LOGIC INTRODUCTION IDEA OF A TRANSCENDENTAL LOGIC I LOGIC IN GENERAL OUR knowledge springs from two fundamental sources of the mind; the first is the capacity of receiving representations (receptivity for impressions), the second is the power of know- ing an object through these representations (spontaneity [in the production] of concepts). Through the first an object is given to us, through the second the object is thought in relation to that [given] representation (which is a mere determination of the mind). Intuition and concepts constitute, therefore, the ele- ments of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition with- out concepts, can yield knowledge. Both may be either pure or empirical. When they contain sensation (which presupposes the actual presence of the object), they are empirical. When there is no mingling of sensation with the representation,they are pure. Sensation may be entitled the material of sensible knowledge. Pure intuition, therefore, contains only the form under which something is intuited; the pure concept only the form of the thought of an object in general. Pure intuitions or pure con- cepts alone are possible a priori, empirical intuitions and empirical concepts only a posteriori. P 093 If the receptivity of our mind, its power of receiving re- presentations in so far as it is in any wise affected, is to be entitled sensibility, then the mind's power of producing repre- sentations from itself, the spontaneity of knowledge, should be called the understanding. Our nature is so constituted that our intuition can never be other than sensible; that is, it con- tains only the mode in which we are affected by objects. The faculty, on the other hand, which enables us to think the object of sensible intuition is the understanding. To neither of these powers may a preference be given over the other. Without sensibility no object would be given to us, without understanding no object would be thought. Thoughts without content are empty, intuitions without concepts are blind. It is, therefore, just as necessary to make our concepts sensible, that is, to add the object to them in intuition, as to make our intuitions intelligible, that is, to bring them under con- cepts. These two powers or capacities cannot exchange their functions. The understanding can intuit nothing, the senses can think nothing. Only through their union can know- ledge arise. But that is no reason for confounding the contribution of either with that of the other; rather is it a strong reason for carefully separating and distinguishing the one from the other. We therefore distinguish the science of the rules of sensibility in general, that is, aesthetic, from the science of the rules of the understanding in general, that is, logic. Logic, again, can be treated in a twofold manner, either as logic of the general or as logic of the special employment of the understanding. The former contains the absolutely necessary rules of thought without which there can be no employment whatsoever of the understanding. It therefore treats of understanding without any regard to difference in the objects to which the understanding may be directed. The logic of the special employment of the understanding contains the rules of correct thinking as regards a certain kind of objects. The former may be called the logic of elements, the latter the organon of this or that science. The latter is com- monly taught in the schools as a propaedeutic to the sciences, though, according to the actual procedure of human reason, it is what is obtained last of all, when the particular science P 094 under question has been already brought to such completion that it requires only a few finishing touches to correct and perfect it. For the objects under consideration must already be known fairly completely before it can be possible to pre- scribe the rules according to which a science of them is to be obtained. General logic is either pure or applied. In the former we abstract from all empirical conditions under which our under- standing is exercised, i.e. from the influence of the senses, the play of imagination, the laws of memory, the force of habit, inclination, etc. , and so from all sources of prejudice, indeed from all causes from which this or that knowledge may arise or seem to arise. For they concern the understanding only in so far as it is being employed under certain circumstances, and to become acquainted with these circumstances experi- ence is required. Pure general logic has to do, therefore, only with principles a priori, and is a canon of understanding and of reason, but only in respect of what is formal in their em- ployment, be the content what it may, empirical or tran- scendental. General logic is called applied, when it is directed to the rules of the employment of understanding under the subjective empirical conditions dealt with by psychology. Applied logic has therefore empirical principles, although it is still indeed in so far general that it refers to the employ- ment of the understanding without regard to difference in the objects. Consequently it is neither a canon of the under- standing in general nor an organon of special sciences, but merely a cathartic of the common understanding. In general logic, therefore, that part which is to constitute the pure doctrine of reason must be entirely separated from that which constitutes applied (though always still general) logic. The former alone is, properly speaking, a science, though indeed concise and dry, as the methodical exposition of a doctrine of the elements of the understanding is bound to be. There are therefore two rules which logicians must always bear in mind, in dealing with pure general logic: 1. As general logic, it abstracts from all content of the knowledge of understanding and from all differences in its objects, and deals with nothing but the mere form of thought. P 095 2. As pure logic, it has nothing to do with empirical prin- ciples, and does not, as has sometimes been supposed, borrow anything from psychology, which therefore has no influence whatever on the canon of the understanding. Pure logic is a body of demonstrated doctrine, and everything in it must be certain entirely a priori. What I call applied logic (contrary to the usual meaning of this title, according to which it should contain certain exercises for which pure logic gives the rules) is a representa- tion of the understanding and of the rules of its necessary employment in concreto, that is, under the accidental sub- jective conditions which may hinder or help its application, and which are all given only empirically. It treats of attention, its impediments and consequences, of the source of error, of the state of doubt, hesitation, and conviction, etc. Pure general logic stands to it in the same relation as pure ethics, which contains only the necessary moral laws of a free will in general, stands to the doctrine of the virtues strictly so called -- the doctrine which considers these laws under the limitations of the feelings, inclinations, and passions to which men are more or less subject. Such a doctrine can never furnish a true and demonstrated science, because, like applied logic, it depends on empirical and psychological principles. II TRANSCENDENTAL LOGIC General logic, as we have shown, abstracts from all con- tent of knowledge, that is, from all relation of knowledge to the object, and considers only the logical form in the relation of any knowledge to other knowledge; that is, it treats of the form of thought in general. But since, as the Transcendental Aes- thetic has shown, there are pure as well as empirical intuitions, a distinction might likewise be drawn between pure and em- pirical thought of objects. In that case we should have a logic in which we do not abstract from the entire content of know- ledge. This other logic, which should contain solely the rules of the pure thought of an object, would exclude only those P 096 modes of knowledge which have empirical content. It would also treat of the origin of the modes in which we know objects, in so far as that origin cannot be attributed to the objects. General logic, on the other hand, has nothing to do with the origin of knowledge, but only considers representations, be they originally a priori in ourselves or only empirically given, according to the laws which the understanding employs when, in thinking, it relates them to one another. It deals therefore only with that form which the understanding is able to impart to the representations, from whatever source they may have arisen. And here I make a remark which the reader must bear well in mind, as it extends its influence over all that follows. Not every kind of knowledge a priori should be called tran- scendental, but that only by which we know that -- and how -- certain representations (intuitions or concepts) can be em- ployed or are possible purely a priori. The term 'transcend- ental', that is to say, signifies such knowledge as concerns the a priori possibility of knowledge, or its a priori employment. Neither space nor any a priori geometrical determination of it is a transcendental representation; what can alone be entitled transcendental is the knowledge that these representations are not of empirical origin, and the possibility that they can yet relate a priori to objects of experience. The application of space to objects in general would likewise be transcendental, but, if restricted solely to objects of sense, it is empirical. The distinction between the transcendental and the empirical belongs therefore only to the critique of knowledge; it does not concern the relation of that knowledge to its objects. In the expectation, therefore, that there may perhaps be concepts which relate a priori to objects, not as pure or sen- sible intuitions, but solely as acts of pure thought -- that is, as concepts which are neither of empirical nor of aesthetic origin -- we form for ourselves by anticipation the idea of a science of the knowledge which belongs to pure understanding and reason, whereby we think objects entirely a priori. Such a science, which should determine the origin, the scope, and P 097 the objective validity of such knowledge, would have to be called transcendental logic, because, unlike general logic, which has to deal with both empirical and pure knowledge of reason, it concerns itself with the laws of understanding and of reason solely in so far as they relate a priori to objects. III THE DIVISION OF GENERAL LOGIC INTO ANALYTIC AND DIALECTIC The question, famed of old, by which logicians were supposed to be driven into a corner, obliged either to have recourse to a pitiful sophism, or to confess their ignorance and consequently the emptiness of their whole art, is the question: What is truth? The nominal definition of truth, that it is the agreement of knowledge with its object, is assumed as granted; the question asked is as to what is the general and sure criterion of the truth of any and every knowledge. To know what questions may reasonably be asked is already a great and necessary proof of sagacity and insight. For if a question is absurd in itself and calls for an answer where none is required, it not only brings shame on the pro- pounder of the question, but may betray an incautious listener into absurd answers, thus presenting, as the ancients said, the ludicrous spectacle of one man milking a he-goat and the other holding a sieve underneath. If truth consists in the agreement of knowledge with its object, that object must thereby be distinguished from other objects; for knowledge is false, if it does not agree with the object to which it is related, even although it contains some- thing which may be valid of other objects. Now a general criterion of truth must be such as would be valid in each and every instance of knowledge, however their objects may vary. It is obvious, however, that such a criterion [being general] cannot take account of the [varying] content of knowledge (relation to its [specific] object). But since truth concerns just this very content, it is quite impossible, and indeed absurd, to ask for a P 098 general test of the truth of such content. A sufficient and at the same time general criterion of truth cannot possibly be given. Since we have already entitled the content of knowledge its matter, we must be prepared to recognise that of the truth of knowledge, so far as its matter is concerned, no general criterion can be demanded. Such a criterion would by its very nature be self-contradictory. But, on the other hand, as regards knowledge in respect of its mere form (leaving aside all content), it is evident that logic, in so far as it expounds the universal and necessary rules of the understanding, must in these rules furnish criteria of truth. Whatever contradicts these rules is false. For the understanding would thereby be made to contradict its own general rules of thought, and so to contradict itself. These criteria, however, concern only the form of truth, that is, of thought in general; and in so far they are quite correct, but are not by themselves sufficient. For although our knowledge may be in complete accordance with logical demands, that is, may not contradict itself, it is still possible that it may be in contradiction with its object. The purely logical criterion of truth, namely, the agreement of knowledge with the general and formal laws of the understanding and reason, is a conditio sine qua non, and is therefore the negative condition of all truth. But further than this logic cannot go. It has no touch- stone for the discovery of such error as concerns not the form but the content. General logic resolves the whole formal procedure of the understanding and reason into its elements, and exhibits them as principles of all logical criticism of our knowledge. This part of logic, which may therefore be entitled analytic, yields what is at least the negative touchstone of truth. Its rules must be applied in the examination and appraising of the form of all knowledge before we proceed to determine whether their content contains positive truth in respect to their object. But since the mere form of knowledge, however completely it may be in agreement with logical laws, is far from being sufficient to determine the material (objective) truth of know- ledge, no one can venture with the help of logic alone to judge regarding objects, or to make any assertion. We must first, independently of logic, obtain reliable information; only P 099 then are we in a position to enquire, in accordance with logical laws, into the use of this information and its connection in a coherent whole, or rather to test it by these laws. There is, however, something so tempting in the possession of an art so specious, through which we give to all our knowledge, how- ever uninstructed we may be in regard to its content, the form of understanding, that general logic, which is merely a canon of judgment, has been employed as if it were an organon for the actual production of at least the semblance of objective assertions, and has thus been misapplied. General logic, when thus treated as an organon, is called dialectic. However various were the significations in which the ancients used 'dialectic' as the title for a science or art, we can safely conclude from their actual employment of it that with them it was never anything else than the logic of illusion. It was a sophistical art of giving to ignorance, and indeed to intentional sophistries, the appearance of truth, by the device of imitat- ing the methodical thoroughness which logic prescribes, and of using its 'topic' to conceal the emptiness of its pretensions. Now it may be noted as a sure and useful warning, that general logic, if viewed as an organon, is always a logic of illusion, that is, dialectical. For logic teaches us nothing whatsoever regarding the content of knowledge, but lays down only the formal conditions of agreement with the understanding; and since these conditions can tell us nothing at all as to the objects concerned, any attempt to use this logic as an instru- ment (organon) that professes to extend and enlarge our knowledge can end in nothing but mere talk -- in which, with a certain plausibility, we maintain, or, if such be our choice, attack, any and every possible assertion. Such instruction is quite unbecoming the dignity of philo- sophy. The title 'dialectic' has therefore come to be otherwise employed, and has been assigned to logic, as a critique of dialectical illusion. This is the sense in which it is to be under- stood in this work. P 100 IV THE DIVISION OF TRANSCENDENTAL LOGIC INTO TRANSCENDENTAL ANALYTIC AND DIALECTIC In a transcendental logic we isolate the understanding -- as above, in the Transcendental Aesthetic, the sensibility -- separating out from our knowledge that part of thought which has its origin solely in the understanding. The employment of this pure knowledge depends upon the condition that objects to which it can be applied be given to us in intuition. In the absence of intuition all our knowledge is without objects, and therefore remains entirely empty. That part of transcen- dental logic which deals with the elements of the pure know- ledge yielded by understanding, and the principles without which no object can be thought, is transcendental analytic. It is a logic of truth. For no knowledge can contradict it without at once losing all content, that is, all relation to any object, and therefore all truth. But since it is very tempting to use these pure modes of knowledge of the understanding and these prin- ciples by themselves, and even beyond the limits of experience, which alone can yield the matter (objects) to which those pure concepts of understanding can be applied, the understanding is led to incur the risk of making, with a mere show of rationality, a material use of its pure and merely formal principles, and of passing judgments upon objects without distinction -- upon objects which are not given to us, nay, perhaps cannot in any way be given. Since, properly, this transcendental analytic should be used only as a canon for passing judgment upon the empirical employment of the understanding, it is misapplied if appealed to as an organon of its general and unlimited application, and if consequently we venture, with the pure understanding alone, to judge synthetically, to affirm, and to decide regarding objects in general. The employment of the pure understanding then becomes dialectical. The second part of transcendental logic must therefore form a critique of this dialectical illusion, and is called transcendental dialectic, not as an art of producing such illusion dogmatically (an art un- fortunately very commonly practised by metaphysical jugglers), but as a critique of understanding and reason in respect of P 101 their hyperphysical employment. It will expose the false, illu- sory character of those groundless pretensions, and in place of the high claims to discover and to extend knowledge merely by means of transcendental principles, it will substitute what is no more than a critical treatment of the pure understanding, for the guarding of it against sophistical illusion. P 102 TRANSCENDENTAL LOGIC FIRST DIVISION TRANSCENDENTAL ANALYTIC TRANSCENDENTAL analytic consists in the dissection of all our a priori knowledge into the elements that pure under- standing by itself yields. In so doing, the following are the points of chief concern: (1) that the concepts be pure and not empirical; (2) that they belong, not to intuition and sensibility, but to thought and understanding; (3) that they be fundamental and be carefully distinguished from those which are derivative or composite; (4) that our table of concepts be complete, covering the whole field of the pure understanding. When a science is an aggregate brought into existence in a merely experimental manner, such completeness can never be guaranteed by any kind of mere estimate. It is possible only by means of an idea of the totality of the a priori knowledge yielded by the understanding; such an idea can furnish an exact classification of the concepts which compose that totality, exhibiting their interconnection in a system. Pure understanding distinguishes itself not merely from all that is empirical but completely also from all sensibility. It is a unity self-subsistent, self-sufficient, and not to be increased by any additions from without. The sum of its knowledge thus constitutes a system, comprehended and determined by one idea. The completeness and articulation of this system can at the same time yield a criterion of the correctness and genuine- ness of all its components. This part of transcendental logic requires, however, for its complete exposition, two books, the one containing the concepts, the other the principles of pure understanding. P 103 TRANSCENDENTAL ANALYTIC BOOK I ANALYTIC OF CONCEPTS By 'analytic of concepts' I do not understand their ana- lysis, or the procedure usual in philosophical investigations, that of dissecting the content of such concepts as may present themselves, and so of rendering them more distinct; but the hitherto rarely attempted dissection of the faculty of the under- standing itself, in order to investigate the possibility of con- cepts a priori by looking for them in the understanding alone, as their birthplace, and by analysing the pure use of this faculty. This is the proper task of a transcendental philosophy; anything beyond this belongs to the logical treatment of con- cepts in philosophy in general. We shall therefore follow up the pure concepts to their first seeds and dispositions in the human understanding, in which they lie prepared, till at last, on the occasion of experience, they are developed, and by the same understanding are exhibited in their purity, freed from the empirical conditions attaching to them. P 104 ANALYTIC OF CONCEPTS CHAPTER I THE CLUE TO THE DISCOVERY OF ALL PURE CONCEPTS OF THE UNDERSTANDING WHEN we call a faculty of knowledge into play, then, as the occasioning circumstances differ, various concepts stand forth and make the faculty known, and allow of their being collected with more or less completeness, in proportion as observation has been made of them over a longer time or with greater acuteness. But when the enquiry is carried on in this mechanical fashion, we can never be sure whether it has been brought to completion. Further, the con- cepts which we thus discover only as opportunity offers, ex- hibit no order and systematic unity, but are in the end merely arranged in pairs according to similarities, and in series accord- ing to the amount of their contents, from the simple on to the more composite -- an arrangement which is anything but sys- tematic, although to a certain extent methodically instituted. Transcendental philosophy, in seeking for its concepts, has the advantage and also the duty of proceeding according to a single principle. For these concepts spring, pure and unmixed, out of the understanding which is an absolute unity; and must therefore be connected with each other according to one con- cept or idea. Such a connection supplies us with a rule, by which we are enabled to assign its proper place to each pure concept of the understanding, and by which we can determine in an a priori manner their systematic completeness. Other- wise we should be dependent in these matters on our own discretionary judgment or merely on chance. P 105 THE TRANSCENDENTAL CLUE TO THE DISCOVERY OF ALL PURE CONCEPTS OF THE UNDERSTANDING Section I THE LOGICAL EMPLOYMENT OF THE UNDERSTANDING The understanding has thus far been explained merely negatively, as a non-sensible faculty of knowledge. Now since without sensibility we cannot have any intuition, understand- ing cannot be a faculty of intuition. But besides intuition there is no other mode of knowledge except by means of concepts. The knowledge yielded by understanding, or at least by the human understanding, must therefore be by means of concepts, and so is not intuitive, but discursive. Whereas all intuitions, as sensible, rest on affections, concepts rest on functions. By 'function' I mean the unity of the act of bringing various repre- sentations under one common representation. Concepts are based on the spontaneity of thought, sensible intuitions on the receptivity of impressions. Now the only use which the under- standing can make of these concepts is to judge by means of them. Since no representation, save when it is an intuition, is in immediate relation to an object, no concept is ever related to an object immediately, but to some other representa- tion of it, be that other representation an intuition, or itself a concept. Judgment is therefore the mediate knowledge of an object, that is, the representation of a representation of it. In every judgment there is a concept which holds of many repre- sentations, and among them of a given representation that is immediately related to an object. Thus in the judgment, 'all bodies are divisible', the concept of the divisible applies to various other concepts, but is here applied in particular to the concept of body, and this concept again to certain appear- ances that present themselves to us. These objects, therefore, are mediately represented through the concept of divisibility. Accordingly, all judgments are functions of unity among our P 106 representations; instead of an immediate representation, a higher representation, which comprises the immediate repre- sentation and various others, is used in knowing the object, and thereby much possible knowledge is collected into one. Now we can reduce all acts of the understanding to judg- ments, and the understanding may therefore be represented as a faculty of judgment. For, as stated above, the under- standing is a faculty of thought. Thought is knowledge by means of concepts. But concepts, as predicates of possible judgments, relate to some representation of a not yet deter- mined object. Thus the concept of body means something, for instance, metal, which can be known by means of that con- cept. It is therefore a concept solely in virtue of its com- prehending other representations, by means of which it can relate to objects. It is therefore the predicate of a possible judgment, for instance, 'every metal is a body'. The functions of the understanding can, therefore, be discovered if we can give an exhaustive statement of the functions of unity in judgments. That this can quite easily be done will be shown in the next section. THE CLUE TO THE DISCOVERY OF ALL PURE CONCEPTS OF THE UNDERSTANDING Section 2 $9 THE LOGICAL FUNCTION OF THE UNDERSTANDING IN JUDGMENTS If we abstract from all content of a judgment, and con- sider only the mere form of understanding, we find that the function of thought in judgment can be brought under four heads, each of which contains three moments. They may be conveniently represented in the following table: P 107 I Quantity of Judgments Universal Particular Singular II III Quality Relation Affirmative Categorical Negative Hypothetical Infinite Disjunctive IV Modality Problematic Assertoric Apodeictic As this division appears to depart in some, though not in any essential respects, from the technical distinctions ordin- arily recognised by logicians, the following observations may serve to guard against any possible misunderstanding. 1. Logicians are justified in saying that, in the employ- ment of judgments in syllogisms, singular judgments can be treated like those that are universal. For, since they have no extension at all, the predicate cannot relate to part only of that which is contained in the concept of the subject, and be excluded from the rest. The predicate is valid of that concept, without any such exception, just as if it were a general concept and had an extension to the whole of which the predicate applied. If, on the other hand, we compare a singular with a universal judgment, merely as knowledge, in respect of quantity, the singular stands to the universal as unity to infinity, and is therefore in itself essentially different from the universal. If, therefore, we estimate a singular judg- ment (judicium singulare), not only according to its own inner validity, but as knowledge in general, according to its quantity in comparison with other knowledge, it is certainly different from general judgments (judicia communia), and in a com- plete table of the moments of thought in general deserves a separate place -- though not, indeed, in a logic limited to the use of judgments in reference to each other. P 108 2. In like manner infinite judgments must, in trans- cendental logic, be distinguished from those that are affirm- ative, although in general logic they are rightly classed with them, and do not constitute a separate member of the division. General logic abstracts from all content of the predicate (even though it be negative); it enquires only whether the predicate be ascribed to the subject or opposed to it. But transcendental logic also considers what may be the worth or content of a logical affirmation that is thus made by means of a merely negative predicate, and what is thereby achieved in the way of addition to our total knowledge. If I should say of the soul, 'It is not mortal', by this negative judgment I should at least have warded off error. Now by the proposition, 'The soul is non-mortal', I have, so far as the logical form is concerned, really made an affirmation. I locate the soul in the unlimited sphere of non-mortal beings. Since the mortal constitutes one part of the whole extension of possible beings, and the non-mortal the other, nothing more is said by my proposition than that the soul is one of the infinite number of things which remain over when I take away all that is mortal. The infinite sphere of all that is possible is thereby only so far limited that the mortal is excluded from it, and that the soul is located in the remaining part of its extension. But, even allowing for such exclusion, this extension still remains infinite, and several more parts of it may be taken away without the con- cept of the soul being thereby in the least increased, or de- termined in an affirmative manner. These judgments, though infinite in respect of their logical extension, are thus, in respect of the content of their knowledge, limitative only, and cannot therefore be passed over in a transcendental table of all moments of thought in judgments, since the function of the understanding thereby expressed may perhaps be of import- ance in the field of its pure a priori knowledge. 3. All relations of thought in judgments are (a) of the predicate to the subject, (b) of the ground to its consequence, (c) of the divided knowledge and of the members of the division, taken together, to each other. In the first kind of P 109 judgments we consider only two concepts, in the second two judgments, in the third several judgments in their relation to each other. The hypothetical proposition, 'If there is a perfect justice, the obstinately wicked are punished', really contains the relation of two propositions, namely, 'There is a perfect justice', and 'The obstinately wicked are punished'. Whether both these propositions are in themselves true, here remains undetermined. It is only the logical sequence which is thought by this judgment. Finally, the disjunctive judgment contains a relation of two or more propositions to each other, a relation not, however, of logical sequence, but of logical opposition, in so far as the sphere of the one excludes the sphere of the other, and yet at the same time of community, in so far as the propositions taken together occupy the whole sphere of the knowledge in question. The disjunctive judg- ment expresses, therefore, a relation of the parts of the sphere of such knowledge, since the sphere of each part is a com- plement of the sphere of the others, yielding together the sum-total of the divided knowledge. Take, for instance, the judgment, 'The world exists either through blind chance, or through inner necessity, or through an external cause'. Each of these propositions occupies a part of the sphere of the possible knowledge concerning the existence of a world in general; all of them together occupy the whole sphere. To take the knowledge out of one of these spheres means placing it in one of the other spheres, and to place it in one sphere means taking it out of the others. There is, therefore, in a disjunctive judging a certain community of the known constitutes, such that they mutually exclude each other, and yet thereby determine in their totality the true know- ledge. For, when taken together, they constitute the whole content of one given knowledge. This is all that need here be considered, so far as concerns what follows. 4. The modality of judgments is a quite peculiar function. Its distinguishing characteristic is that it contributes nothing to the content of the judgment (for, besides quantity, quality, and relation, there is nothing that constitutes the content of a judgment), but concerns only the value of the copula in relation to thought in general. Problematic judgments are those in which affirmation or negation is taken as merely P 110 possible (optional). In assertoric judgments affirmation or negation is viewed as real (true), and in apodeictic judgments as necessary. Thus the two judgments, the relation of which constitutes the hypothetical judgment (antecedens et con- sequens), and likewise the judgments the reciprocal relation of which forms the disjunctive judgment (members of the division), are one and all problematic only. In the above example, the proposition, 'There is a perfect justice', is not stated assertorically, but is thought only as an optional judg- ment, which it is possible to assume; it is only the logical sequence which is assertoric. Such judgments may therefore be obviously false, and yet, taken problematically, may be con- ditions of the knowledge of truth. Thus the judgment 'The world exists by blind chance', has in the disjunctive judgment only problematic meaning, namely, as a proposition that may for a moment be assumed. At the same time, like the indica- tion of a false road among the number of all those roads that can be taken, it aids in the discovery of the true proposition. The problematic proposition is therefore that which expresses only logical (which is not objective) possibility -- a free choice of admitting such a proposition, and a purely optional admission of it into the understanding. The assertoric pro- position deals with logical reality or truth. Thus, for instance, in a hypothetical syllogism the antecedent is in the major premiss problematic, in the minor assertoric, and what the syllogism shows is that the consequence follows in accordance with the laws of the understanding. The apodeictic proposi- tion thinks the assertoric as determined by these laws of the understanding, and therefore as affirming a priori; and in this manner it expresses logical necessity. Since everything is thus incorporated in the understanding step by step -- inas- much as we first judge something problematically, then maintain its truth assertorically, and finally affirm it as in- separably united with the understanding, that is, as necessary and apodeictic -- we are justified in regarding these three functions of modality as so many moments of thought. Just as if thought were in the problematic a function of the understanding; in the assertoric, of the faculty of judgment; in the apodeictic, of reason. This is a remark which will be explained in the sequel. P 111 THE CLUE TO THE DISCOVERY OF ALL PURE CONCEPTS OF THE UNDERSTANDING Section 3 $10 THE PURE CONCEPTS OF THE UNDERSTANDING, OR CATEGORIES General logic, as has been repeatedly said, abstracts from all content of knowledge, and looks to some other source, whatever that may be, for the representations which it is to transform into concepts by process of analysis. Tran- scendental logic, on the other hand, has lying before it a mani- fold of a priori sensibility, presented by transcendental aes- thetic, as material for the concepts of pure understanding. In the absence of this material those concepts would be with- out any content, therefore entirely empty. Space and time contain a manifold of pure a priori intuition, but at the same time are conditions of the receptivity of our mind -- conditions under which alone it can receive representations of objects, and which therefore must also always affect the concept of these objects. But if this manifold is to be known, the spontaneity of our thought requires that it be gone through in a certain way, taken up, and connected. This act I name synthesis. By synthesis, in its most general sense, I understand the act of putting different representations together, and of grasp- ing what is manifold in them in one [act of] knowledge. Such a synthesis is pure, if the manifold is not empirical but is given a priori, as is the manifold in space and time. Before we can analyse our representations, the representations must them- selves be given, and therefore as regards content no concepts can first arise by way of analysis. Synthesis of a manifold (be it given empirically or a priori) is what first gives rise to know- ledge. This knowledge may, indeed, at first, be crude and con- fused, and therefore in need of analysis. Still the synthesis is that which gathers the elements for knowledge, and unites them to [form] a certain content. It is to synthesis, therefore, P 112 that we must first direct our attention, if we would determine the first origin of our knowledge. Synthesis in general, as we shall hereafter see, is the mere result of the power of imagination, a blind but indispensable function of the soul, without which we should have no know- ledge whatsoever, but of which we are scarcely ever conscious. To bring this synthesis to concepts is a function which belongs to the understanding, and it is through this function of the understanding that we first obtain knowledge properly so called. Pure synthesis, represented in its most general aspect, gives the pure concept of the understanding. By this pure syn- thesis I understand that which rests upon a basis of a priori synthetic unity. Thus our counting, as is easily seen in the case of larger numbers, is a synthesis according to concepts, be- cause it is executed according to a common ground of unity, as, for instance, the decade. In terms of this concept, the unity of the synthesis of the manifold is rendered necessary. By means of analysis different representations are brought under one concept -- a procedure treated of in general logic. What transcendental logic, on the other hand, teaches, is how we bring to concepts, not representations, but the pure syn- thesis of representations. What must first be given -- with a view to the a priori knowledge of all objects -- is the manifold of pure intuition; the second factor involved is the synthesis of this manifold by means of the imagination. But even this does not yet yield knowledge. The concepts which give unity to this pure synthesis, and which consist solely in the representation of this necessary synthetic unity, furnish the third requisite for the knowledge of an object; and they rest on the under- standing. The same function which gives unity to the various repre- sentations in a judgment also gives unity to the mere syn- thesis of various representations in an intuition; and this unity, in its most general expression, we entitle the pure con- cept of the understanding. The same understanding, through the same operations by which in concepts, by means of ana- lytical unity, it produced the logical form of a judgment, also introduces a transcendental content into its representa- tions, by means of the synthetic unity of the manifold in intui- P 113 tion in general. On this account we are entitled to call these representations pure concepts of the understanding, and to regard them as applying a priori to objects -- a conclusion which general logic is not in a position to establish. In this manner there arise precisely the same number of pure concepts of the understanding which apply a priori to objects of intuition in general, as, in the preceding table, there have been found to be logical functions in all possible judg- ments. For these functions specify the understanding com- pletely, and yield an exhaustive inventory of its powers. These concepts we shall, with Aristotle, call categories, for our primary purpose is the same as his, although widely diverging from it in manner of execution. TABLE OF CATEGORIES I Of Quantity Unity Plurality Totality II III Of Quality Of Relation Reality Of Inherence and Subsistence Negation (substantia et accidens) Limitation Of Causality and Dependence (cause and effect) Of Community (reciprocity between agent and patient) IV Of Modality Possibility -- Impossibility Existence -- Non-existence Necessity -- Contingency This then is the list of all original pure concepts of syn- thesis that the understanding contains within itself a priori. P 114 Indeed, it is because it contains these concepts that it is called pure understanding; for by them alone can it under- stand anything in the manifold of intuition, that is, think an object of intuition. This division is developed systematically from a common principle, namely, the faculty of judgment (which is the same as the faculty of thought). It has not arisen rhapsodically, as the result of a haphazard search after pure concepts, the complete enumeration of which as based on induction only, could never be guaranteed. Nor could we, if this were our procedure, discover why just these concepts, and no others, have their seat in the pure understanding. It was an enterprise worthy of an acute thinker like Aristotle to make search for these fundamental concepts. But as he did so on no principle, he merely picked them up as they came his way, and at first procured ten of them, which he called categories (predicaments). Afterwards he believed that he had discovered five others, which he added under the name of post-predica- ments. But his table still remained defective. Besides, there are to be found in it some modes of pure sensibility (quando, ubi, situs, also prius, simul), and an empirical concept (motus), none of which have any place in a table of the concepts that trace their origin to the understanding. Aristotle's list also enumerates among the original concepts some derivative con- cepts (actio, passio); and of the original concepts some are entirely lacking. In this connection, it is to be remarked that the categories, as the true primary concepts of the pure understanding, have also their pure derivative concepts. These could not be passed over in a complete system of transcendental philosophy, but in a merely critical essay the simple mention of the fact may suffice. I beg permission to entitle these pure but derivative con- cepts of the understanding the predicables of the pure under- standing -- to distinguish them from the predicaments [i.e. the categories]. If we have the original and primitive concepts, it is easy to add the derivative and subsidiary, and so to give a complete picture of the family tree of the [concepts of] pure understanding. Since at present we are concerned not with the completeness of the system, but only with the principles to be followed in its construction, I reserve this supplementary work P 115 for another occasion. It can easily be carried out, with the aid of the ontological manuals -- for instance, by placing under the category of causality the predicables of force, action, passion; under the category of community the predicables of presence, resistance; under the predicaments of modality the predicables of coming to be, ceasing to be, change, etc. The categories, when combined with the modes of pure sen- sibility, or with one another, yield a large number of derivative a priori concepts. To note, and, where possible, to give a com- plete inventory of these concepts, would be a useful and not unpleasant task, but it is a task from which we can here be absolved. In this treatise, I purposely omit the definitions of the cate- gories, although I may be in possession of them. I shall pro- ceed to analyse these concepts only so far as is necessary in connection with the doctrine of method which I am propound- ing. In a system of pure reason, definitions of the categories would rightly be demanded, but in this treatise they would merely divert attention from the main object of the enquiry, arousing doubts and objections which, without detriment to what is essential to our purposes, can very well be reserved for another occasion. Meanwhile, from the little that I have said, it will be obvious that a complete glossary, with all the requisite explanations, is not only a possible, but an easy task. The divi- sions are provided; all that is required is to fill them; and a systematic 'topic', such as that here given, affords sufficient guidance as to the proper location of each concept, while at the same time indicating which divisions are still empty. $II This table of categories suggests some nice points, which may perhaps have important consequences in regard to the scientific form of all modes of knowledge obtainable by reason. For that this table is extremely useful in the theoretical part of philosophy, and indeed is indispensable as supplying the com- plete plan of a whole science, so far as that science rests on a - priori concepts, and as dividing it systematically according to P 116 determinate principles, is already evident from the fact that the table contains all the elementary concepts of the under- standing in their completeness, nay, even the form of a system of them in the human understanding, and accordingly indi- cates all the momenta of a projected speculative science, and even their order, as I have elsewhere shown. P 116n * Metaphysical First Principles of Natural Science. P 116 The first of the considerations suggested by the table is that while it contains four classes of the concepts of under- standing, it may, in the first instance, be divided into two groups; those in the first group being concerned with objects of intuition, pure as well as empirical, those in the second group with the existence of these objects, in their relation either to each other or to the understanding. The categories in the first group I would entitle the mathe- matical, those in the second group the dynamical. The former have no correlates; these are to be met with only in the second group. This distinction must have some ground in the nature of the understanding. Secondly, in view of the fact that all a priori division of concepts must be by dichotomy, it is significant that in each class the number of the categories is always the same, namely, three. Further, it may be observed that the third category in each class always arises from the combination of the second category with the first. Thus allness or totality is just plurality considered as unity; limitation is simply reality combined with negation; commun- ity is the causality of substances reciprocally determining one another; lastly, necessity is just the existence which is given through possibility itself. It must not be supposed, however, that the third category is therefore merely a derivative, and not a primary, concept of the pure understanding. For the com- bination of the first and second concepts, in order that the third may be produced, requires a special act of the understand- ing, which is not identical with that which is exercised in the case of the first and the second. Thus the concept of a number (which belongs to the category of totality) is not always possible simply upon the presence of concepts of plurality and unity P 117 (for instance, in the representation of the infinite); nor can I, by simply combining the concept of a cause and that of a sub- stance, at once have understanding of influence, that is, how a substance can be the cause of something in another substance. Obviously in these cases, a separate act of the understanding is demanded; and similarly in the others. Thirdly, in the case of one category, namely, that of com- munity, which is found in the third group, its accordance with the form of a disjunctive judgment -- the form which corre- sponds to it in the table of logical functions -- is not as evident as in the case of the others. To gain assurance that they do actually accord, we must observe that in all disjunctive judgments the sphere (that is, the multiplicity which is contained in any one judgment) is represented as a whole divided into parts (the subordinate con- cepts), and that since no one of them can be contained under any other, they are thought as co-ordinated with, not sub- ordinated to, each other, and so as determining each other, not in one direction only, as in a series, but reciprocally, as in an aggregate -- if one member of the division is posited, all the rest are excluded, and conversely. Now in a whole which is made up of things, a similar com- bination is being thought; for one thing is not subordinated, as effect, to another, as cause of its existence, but, simultane- ously and reciprocally, is co-ordinated with it, as cause of the determination of the other (as, for instance, in a body the parts of which reciprocally attract and repel each other). This is a quite different kind of connection from that which is found in the mere relation of cause to effect (of ground to conse- quence), for in the latter relation the consequence does not in its turn reciprocally determine the ground, and therefore does not constitute with it a whole -- thus the world, for instance, does not with its Creator serve to constitute a whole. The procedure which the understanding follows in representing to itself the sphere of a divided concept it likewise follows when it thinks a thing as divisible; and just as, in the former case, the members of a division exclude each other, and yet are com- P 118 bined in one sphere, so the understanding represents to itself the parts of the latter as existing (as substances) in such a way that, while each exists independently of the others, they are yet combined together in one whole. $12 In the transcendental philosophy of the ancients there is included yet another chapter containing pure concepts of the understanding which, though not enumerated among the cate- gories, must, on their view, be ranked as a priori concepts of objects. This, however, would amount to an increase in the number of the categories, and is therefore not feasible. They are propounded in the proposition, so famous among the Schoolmen, quodlibet ens est unum, verum, bonum. Now, although the application of this principle has proved very meagre in consequences, and has indeed yielded only proposi- tions that are tautological, and therefore in recent times has retained its place in metaphysics almost by courtesy only, yet, on the other hand, it represents a view which, however empty it may seem to be, has maintained itself over this very long period. It therefore deserves to be investigated in respect of its origin, and we are justified in conjecturing that it has its ground in some rule of the understanding which, as often happens, has only been wrongly interpreted. These supposedly transcendental predicates of things are, in fact, nothing but logical requirements and criteria of all knowledge of things in general, and prescribe for such knowledge the categories of quantity, namely, unity, plurality, and totality. But these categories, which, properly regarded, must be taken as material, belonging to the possibility of the things themselves [empirical objects], have, in this further application, been used only in their formal meaning, as being of the nature of logical requis- ites of all knowledge, and yet at the same time have been incautiously converted from being criteria of thought to be pro- perties of things in themselves. In all knowledge of an object there is unity of concept, which may be entitled qualitative unity, so far as we think by it only the unity in the combination of the manifold of our knowledge: as, for example, the unity of the theme in a play, a speech, or a story. Secondly, there is P 119 truth, in respect of its consequences. The greater the number of true consequences that follow from a given concept, the more criteria are there of its objective reality. This might be entitled the qualitative plurality of characters, which belong to a concept as to a common ground (but are not thought in it, as quantity). Thirdly, and lastly, there is perfection, which con- sists in this, that the plurality together leads back to the unity of the concept, and accords completely with this and with no other concept. This may be entitled the qualitative complete- ness (totality). Hence it is evident that these logical criteria of the possibility of knowledge in general are the three categories of quantity, in which the unity in the production of the quantum has to be taken as homogeneous throughout; and that these categories are here being transformed so as also to yield con- nection of heterogeneous knowledge in one consciousness, by means of the quality of the knowledge as the principle of the connection. Thus the criterion of the possibility of a concept (not of an object) is the definition of it, in which the unity of the concept, the truth of all that may be immediately deduced from it, and finally, the completeness of what has been thus de- duced from it, yield all that is required for the construction of the whole concept. Similarly, the criterion of an hypothesis consists in the intelligibility of the assumed ground of explana- tion, that is, in its unity (without any auxiliary hypothesis); in the truth of the consequences that can be deduced from it (their accordance with themselves and with experience); and finally, in the completeness of the ground of explanation of these consequences, which carry us back to neither more nor less than was assumed in the hypothesis, and so in an a pos- teriori analytic manner give us back and accord with what has previously been thought in a synthetic a priori manner. We have not, therefore, in the concepts of unity, truth, and per- fection, made any addition to the transcendental table of the categories, as if it were in any respect imperfect. All that we have done is to bring the employment of these concepts under general logical rules, for the agreement of knowledge with itself -- the question of their relation to objects not being in any way under discussion. P 120 ANALYTIC OF CONCEPTS CHAPTER II THE DEDUCTION OF THE PURE CONCEPTS OF UNDERSTANDING Section 1 $13 THE PRINCIPLES OF ANY TRANSCENDENTAL DEDUCTION JURISTS, when speaking of rights and claims, distinguish in a legal action the question of right (quid juris) from the question of fact (quid facti); and they demand that both be proved. Proof of the former, which has to state the right or the legal claim, they entitle the deduction. Many empirical concepts are employed without question from anyone. Since experience is always available for the proof of their objective reality, we be- lieve ourselves, even without a deduction, to be justified in ap- propriating to them a meaning, an ascribed significance. But there are also usurpatory concepts, such as fortune, fate, which, though allowed to circulate by almost universal indul- gence, are yet from time to time challenged by the question: quid juris. This demand for a deduction involves us in con- siderable perplexity, no clear legal title, sufficient to justify their employment, being obtainable either from experience or from reason. Now among the manifold concepts which form the highly P 121 complicated web of human knowledge, there are some which are marked out for pure a priori employment, in complete in- dependence of all experience; and their right to be so em- ployed always demands a deduction. For since empirical proofs do not suffice to justify this kind of employment, we are faced by the problem how these concepts can relate to objects which they yet do not obtain from any experience. The explanation of the manner in which concepts can thus relate a priori to objects I entitle their transcendental deduction; and from it I distinguish empirical deduction, which shows the manner in which a concept is acquired through experience and through reflection upon experience, and which therefore concerns, not its legitimacy, but only its de facto mode of origination. We are already in possession of concepts which are of two quite different kinds, and which yet agree in that they relate to objects in a completely a priori manner, namely, the con- cepts of space and time as forms of sensibility, and the cate- gories as concepts of understanding. To seek an empirical de- duction of either of these types of concept would be labour entirely lost. For their distinguishing feature consists just in this, that they relate to their objects without having borrowed from experience anything that can serve in the representation of these objects. If, therefore, a deduction of such concepts is indispensable, it must in any case be transcendental. We can, however, with regard to these concepts, as with regard to all knowledge, seek to discover in experience, if not the principle of their possibility, at least the occasioning causes of their production. The impressions of the senses supplying the first stimulus, the whole faculty of knowledge opens out to them, and experience is brought into exist- ence. That experience contains two very dissimilar elements, namely, the matter of knowledge [obtained] from the senses, and a certain form for the ordering of this matter, [obtained] from the inner source of the pure intuition and thought which, on occasion of the sense-impressions, are first brought into action and yield concepts. Such an investigation of the first strivings of our faculty of knowledge, whereby it advances from particular perceptions to universal concepts, is un- doubtedly of great service. We are indebted to the celebrated P 122 Locke for opening out this new line of enquiry. But a deduc- tion of the pure a priori concepts can never be obtained in this manner; it is not to be looked for in any such direction. For in view of their subsequent employment, which has to be entirely independent of experience, they must be in a position to show a certificate of birth quite other than that of descent from experiences. Since this attempted physiological deriva- tion concerns a quaestio facti, it cannot strictly be called deduction; and I shall therefore entitle it the explanation of the possession of pure knowledge. Plainly the only deduction that can be given of this knowledge is one that is transcen- dental, not empirical. In respect to pure a priori concepts the latter type of deduction is an utterly useless enterprise which can be engaged in only by those who have failed to grasp the quite peculiar nature of these modes of know- ledge. But although it may be admitted that the only kind of deduction of pure a priori knowledge which is possible is on transcendental lines, it is not at once obvious that a deduc- tion is indispensably necessary. We have already, by means of a transcendental deduction, traced the concepts of space and time to their sources, and have explained and determined their a priori objective validity. Geometry, however, proceeds with security in knowledge that is completely a priori, and has no need to beseech philosophy for any certificate of the pure and legitimate descent of its fundamental concept of space. But the concept is employed in this science only in its reference to the outer sensible world -- of the intuition of which space is the pure form -- where all geometrical knowledge, grounded as it is in a priori intuition, possesses immediate evidence. The objects, so far as their form is concerned, are given, through the very knowledge of them, a priori in intuition. *********** otherwise; it is with them that the unavoidable demand for a transcendental deduction, not only of themselves, but also of the concept of space, first originates. For since they speak of objects through predicates not of intuition and sensibility but of pure a priori thought, they relate to objects universally, P 123 that is, apart from all conditions of sensibility. Also, not being grounded in experience, they cannot, in a priori intuition, exhibit any object such as might, prior to all experience, serve as ground for their synthesis. For these reasons, they arouse suspicion not merely in regard to the objective validity and the limits of their own employment, but owing to their tendency to employ the concept of space beyond the conditions of sensible intuition, that concept also they render ambiguous; and this, indeed, is why we have already found a transcendental deduction of it necessary. The reader must therefore be convinced of the unavoidable necessity of such a transcendental deduction before he has taken a single step in the field of pure reason. Otherwise he proceeds blindly, and after manifold wanderings must come back to the same ignorance from which he started. At the same time, if he is not to lament over obscurity in matters which are by their very nature deeply veiled, or to be too easily discouraged in the removal of obstacles, he must have a clear foreknowledge of the inevitable difficulty of the undertaking. For we must either completely surrender all claims to make judgments of pure reason in the most highly esteemed of all fields, that which transcends the limits of all possible experience, or else bring this critical enquiry to completion. We have already been able with but little difficulty to explain how the concepts of space and time, although a priori modes of knowledge, must necessarily relate to objects, and how independently of all experience they make possible a synthetic knowledge of objects. For since only by means of such pure forms of sensibility can an object appear to us, and so be an object of empirical intuition, space and time are pure intuitions which contain a priori the condition of the possibility of objects as appearances, and the synthesis which takes place in them has objective validity. The categories of understanding, on the other hand, do not represent the conditions under which objects are given in intuition. Objects may, therefore, appear to us without P 124 their being under the necessity of being related to the functions of understanding; and understanding need not, therefore, contain their a priori conditions. Thus a difficulty such as we did not meet with in the field of sensibility is here presented, namely, how subjective conditions of thought can have objective validity, that is, can furnish conditions of the possibility of all knowledge of objects. For appearances can certainly be given in intuition independently of functions of the understanding. Let us take, for instance, the concept of cause, which signifies a special kind of synthesis, whereby upon something, A, there is posited something quite different, B, according to a rule. It is not manifest a priori why appear- ances should contain anything of this kind (experiences cannot be cited in its proof, for what has to be established is the objective validity of a concept that is a priori); and it is therefore a priori doubtful whether such a concept be not perhaps altogether empty, and have no object anywhere among appearances. That objects of sensible intuition must conform to the formal conditions of sensibility which lie a priori in the mind is evident, because otherwise they would not be objects for us. But that they must likewise conform to the conditions which the understanding requires for the synthetic unity of thought, is a conclusion the grounds of which are by no means so obvious. Appearances might very well be so constituted that the understanding should not find them to be in accordance with the Conditions of its unity. Everything might be in such confusion that, for instance, in the series of appearances nothing presented itself which might yield a rule of synthesis and so answer to the concept of cause and effect. This concept would then be altogether empty, null, and meaningless. But since intuition stands in no need whatsoever of the functions of thought, appearances would none the less present objects to our intuition. If we thought to escape these toilsome enquiries by saying that experience continually presents examples of such regu- larity among appearances and so affords abundant oppor- tunity of abstracting the concept of cause, and at the same time of verifying the objective validity of such a concept, we should be overlooking the fact that the concept of cause can P 125 never arise in this manner. It must either be grounded com- pletely a priori in the understanding, or must be entirely given up as a mere phantom of the brain. For this concept makes strict demand that something, A, should be such that some- thing else, B, follows from it necessarily and in accordance with an absolutely universal rule. Appearances do indeed pre- sent cases from which a rule can be obtained according to which something usually happens, but they never prove the sequence to be necessary. To the synthesis of cause and effect there belongs a dignity which cannot be empirically expressed, namely that the effect not only succeeds upon the cause, but that it is posited through it and arises out of it. This strict universality of the rule is never a characteristic of empirical rules; they can acquire through induction only com- parative universality, that is, extensive applicability. If we were to treat pure concepts of understanding as merely em- pirical products, we should be making a complete change in [the manner of] their employment. $14 Transition to the Transcendental Deduction of the Categories There are only two possible ways in which synthetic re- presentations and their objects can establish connection, obtain necessary relation to one another, and, as it were, meet one another. Either the object alone must make the repre- sentation possible, or the representation alone must make the object possible. In the former case, this relation is only em- pirical, and the representation is never possible a priori. This is true of appearances, as regards that [element] in them which belongs to sensation. In the latter case, representation in itself does not produce its object in so far as existence is concerned, for we are not here speaking of its causality by means of the will. None the less the representation is a priori determinant of the object, if it be the case that only through P 126 the representation is it possible to know anything as an object. Now there are two conditions under which alone the know- ledge of an object is possible, first, intuition, through which it is given, though only as appearance; secondly, concept, through which an object is thought corresponding to this in- tuition. It is evident from the above that the first condition, namely, that under which alone objects can be intuited, does actually lie a priori in the mind as the formal ground of the objects. All appearances necessarily agree with this formal condition of sensibility, since only through it can they appear, that is, be empirically intuited and given. The question now arises whether a priori concepts do not also serve as ante- cedent conditions under which alone anything can be, if not intuited, yet thought as object in general. In that case all em- pirical knowledge of objects would necessarily conform to such concepts, because only as thus presupposing them is anything possible as object of experience. Now all experience does indeed contain, in addition to the intuition of the senses through which something is given, a concept of an object as being thereby given, that is to say, as appearing. Concepts of objects in general thus underlie all empirical knowledge as its a priori conditions. The objective validity of the categories as a priori concepts rests, therefore, on the fact that, so far as the form of thought is concerned, through them alone does experience become possible. They relate of necessity and a priori to objects of experience, for the reason that only by means of them can any object whatsoever of experience be thought. The transcendental deduction of all a priori concepts has thus a principle according to which the whole enquiry must be directed, namely, that they must be recognised as a priori conditions of the possibility of experience, whether of the intuition which is to be met with in it or of the thought. Con- cepts which yield the objective ground of the possibility of experience are for this very reason necessary. But the unfold- ing of the experience wherein they are encountered is not their deduction; it is only their illustration. For on any such P 127 exposition they would be merely accidental. Save through their original relation to possible experience, in which all objects of knowledge are found, their relation to any one object would be quite incomprehensible. The illustrious Locke, failing to take account of these con- siderations, and meeting with pure concepts of the understand- ing in experience, deduced them also from experience, and yet proceeded so inconsequently that he attempted with their aid to obtain knowledge which far transcends all limits of ex- perience. David Hume recognised that, in order to be able to do this, it was necessary that these concepts should have an a priori origin. But since he could not explain how it can be possible that the understanding must think concepts, which are not in themselves connected in the understanding, as being necessarily connected in the object, and since it never occurred to him that the understanding might itself, perhaps, through these concepts, be the author of the experience in which its objects are found, he was constrained to derive them from experience, namely, from a subjective necessity (that is, from custom), which arises from repeated association in experience, and which comes mistakenly to be regarded as objective. But from these premisses he argued quite consistently. It is im- possible, he declared, with these concepts and the principles to which they give rise, to pass beyond the limits of experience. *There are three original sources (capacities or faculties of the soul) which contain the conditions of the possibility of all experience, and cannot themselves be derived from any other faculty of the mind, namely, sense, imagination, and appercep- tion. Upon them are grounded (1) the synopsis of the manifold a priori through sense; (2) the synthesis of this manifold through imagination; finally (3) the unity of this synthesis through original apperception. All these faculties have a transcendental (as well as an empirical) employment which concerns the form alone, and is possible a priori. As regards sense, we have treated of this above in the first part; we shall now endeavour to comprehend the nature of the other two. P 128 Now this empirical derivation, in which both philosophers agree, cannot be reconciled with the scientific a priori know- ledge which we do actually possess, namely, pure mathematics and general science of nature; and this fact therefore suffices to disprove such derivation. While the former of these two illustrious men opened a wide door to enthusiasm -- for if reason once be allowed such rights, it will no longer allow itself to be kept within bounds by vaguely defined recommendations of moderation -- the other gave himself over entirely to scepticism, having, as he believed, discovered that what had hitherto been regarded as reason was but an all-prevalent illusion infecting our faculty of know- ledge. We now propose to make trial whether it be not possible to find for human reason safe conduct between these two rocks, assigning to her determinate limits, and yet keeping open for her the whole field of her appropriate activities. But first I shall introduce a word of explanation in regard to the categories. They are concepts of an object in general, by means of which the intuition of an object is regarded as deter- mined in respect of one of the logical functions of judgment. Thus the function of the categorical judgment is that of the relation of subject to predicate; for example, 'All bodies are divisible'. But as regards the merely logical employment of the understanding, it remains undetermined to which of the two concepts the function of the subject, and to which the function of predicate, is to be assigned. For we can also say, 'Something divisible is a body'. But when the concept of body is brought under the category of substance, it is thereby de- termined that its empirical intuition in experience must always be considered as subject and never as mere predicate. Simi- larly with all the other categories. P 129 THE DEDUCTION OF THE PURE CONCEPTS OF UNDERSTANDING Section 2 THE A PRIORI GROUNDS OF THE POSSIBILITY OF EXPERIENCE THAT a concept, although itself neither contained in the con- cept of possible experience nor consisting of elements of a possible experience, should be produced completely a priori and should relate to an object, is altogether contradictory and impossible. For it would then have no content, since no intui- tion corresponds to it; and intuitions in general, through which objects can be given to us, constitute the field, the whole ob- ject, of possible experience. An a priori concept which did not relate to experience would be only the logical form of a concept, not the concept itself through which something is thought. Pure a priori concepts, if such exist, cannot indeed con- tain anything empirical; yet, none the less, they can serve solely as a priori conditions of a possible experience. Upon this ground alone can their objective reality rest. If, therefore, we seek to discover how pure concepts of understanding are possible, we must enquire what are the a priori conditions upon which the possibility of experience rests, and which remain as its underlying grounds when every- thing empirical is abstracted from appearances. A concept which universally and adequately expresses such a normal and P 130 objective condition of experience would be entitled a pure con- cept of understanding. Certainly, once I am in possession of pure concepts of understanding, I can think objects which may be impossible, or which, though perhaps in themselves possible, cannot be given in any experience. For in the connecting of these concepts something may be omitted which yet neces- sarily belongs to the condition of a possible experience (as in the concept of a spirit). Or, it may be, pure concepts are ex- tended further than experience can follow (as with the concept of God). But the elements of all modes of a priori knowledge, even of capricious and incongruous fictions, though they cannot, indeed, be derived from experience, since in that case they would not be knowledge a priori, must none the less always contain the pure a priori conditions of a possible ex- perience and of an empirical object. Otherwise nothing would be thought through them, and they themselves, being without data, could never arise even in thought. The concepts which thus contain a priori the pure thought involved in every experience, we find in the categories. If we can prove that by their means alone an object can be thought, this will be a sufficient deduction of them, and will justify their objective validity. But since in such a thought more than simply the faculty of thought, the understanding, is brought into play, and since this faculty itself, as a faculty of knowledge that is meant to relate to objects, calls for explanation in regard to the possibility of such relation, we must first of all consider, not in their empirical but in their transcendental constitution, the subjective sources which form the a priori foundation of the possibility of experience. If each representation were completely foreign to every other, standing apart in isolation, no such thing as knowledge would ever arise. For knowledge is [essentially] a whole in which representations stand compared and connected. As sense contains a manifold in its intuition, I ascribe to it a synopsis. But to such synopsis a synthesis must always correspond; re- ceptivity can make knowledge possible only when combined with spontaneity. Now this spontaneity is the ground of a threefold synthesis which must necessarily be found in all knowledge; namely, the apprehension of representations as modifications of the mind in intuition, their reproduction in P 131 imagination, and their recognition in a concept. These point to three subjective sources of knowledge which make possible the understanding itself -- and consequently all experience as its empirical product. Preliminary Remark The deduction of the categories is a matter of such ex- treme difficulty, compelling us to penetrate so deeply into the first grounds of the possibility of our knowledge in general, that in order to avoid the elaborateness of a complete theory, and yet at the same time to omit nothing in so indispensable an enquiry, I have found it advisable in the four following pass- ages rather to prepare than to instruct the reader. System- atic exposition of these elements of the understanding is first given in Section 3, immediately following. The reader must not therefore be deterred by obscurities in these earlier sections. They are unavoidable in an enterprise never before attempted. They will, as I trust, in the section referred to, finally give way to complete insight. 1. The Synthesis of Apprehension in Intuition Whatever the origin of our representations, whether they are due to the influence of outer things, or are produced through inner causes, whether they arise a priori, or being appearances have an empirical origin, they must all, as modi- fications of the mind, belong to inner sense. All our know- ledge is thus finally subject to time, the formal condition of inner sense. In it they must all be ordered, connected, and brought into relation. This is a general observation which, throughout what follows, must be borne in mind as being quite fundamental. Every intuition contains in itself a manifold which can be represented as a manifold only in so far as the mind distin- guishes the time in the sequence of one impression upon another; for each representation, in so far as it is contained in a single moment, can never be anything but absolute unity. In order that unity of intuition may arise out of this manifold (as is required in the representation of space) it must first be run through, and held together. This act I name the synthesis of apprehension, because it is directed immediately upon intuition, which does indeed offer a manifold, but a manifold which can P 132 never be represented as a manifold, and as contained in a single representation, save in virtue of such a synthesis. This synthesis of apprehension must also be exercised a priori, that is, in respect of representations which are not empirical. For without it we should never have a priori the representations either of space or of time. They can be pro- duced only through the synthesis of the manifold which sen- sibility presents in its original receptivity. We have thus a pure synthesis of apprehension. 2. The Synthesis of Reproduction in Imagination It is a merely empirical law, that representations which have often followed or accompanied one another finally be- come associated, and so are set in a relation whereby, even in the absence of the object, one of these representations can, in accordance with a fixed rule, bring about a transition of the mind to the other. But this law of reproduction presupposes that appearances are themselves actually subject to such a rule, and that in the manifold of these representations a co- existence or sequence takes place in conformity with certain rules. Otherwise our empirical imagination would never find opportunity for exercise appropriate to its powers, and so would remain concealed within the mind as a dead and to us unknown faculty. If cinnabar were sometimes red, sometimes black, sometimes light, sometimes heavy, if a man changed sometimes into this and sometimes into that animal form, if the country on the longest day were sometimes covered with fruit, sometimes with ice and snow, my empirical imagina- tion would never find opportunity when representing red colour to bring to mind heavy cinnabar. Nor could there be an empirical synthesis of reproduction, if a certain name were sometimes given to this, sometimes to that object, or were one and the same thing named sometimes in one way, sometimes in another, independently of any rule to which appearances are in themselves subject. There must then be something which, as the a priori ground of a necessary synthetic unity of appearances, makes their reproduction possible. What that something is we P 133 soon discover, when we reflect that appearances are not things in themselves, but are the mere play of our representa- tions, and in the end reduce to determinations of inner sense. For if we can show that even our purest a priori intuitions yield no knowledge, save in so far as they contain a com- bination of the manifold such as renders a thoroughgoing synthesis of reproduction possible, then this synthesis of im- agination is likewise grounded, antecedently to all experi- ence, upon a priori principles; and we must assume a pure transcendental synthesis of imagination as conditioning the very possibility of all experience. For experience as such neces- sarily presupposes the reproducibility of appearances. When I seek to draw a line in thought, or to think of the time from one noon to another, or even to represent to myself some par- ticular number, obviously the various manifold representa- tions that are involved must be apprehended by me in thought one after the other. But if I were always to drop out of thought the preceding representations (the first parts of the line, the antecedent parts of the time period, or the units in the order represented), and did not reproduce them while advancing to those that follow, a complete representation would never be obtained: none of the above-mentioned thoughts, not even the purest and most elementary representations of space and time, could arise. The synthesis of apprehension is thus inseparably bound up with the synthesis of reproduction. And as the former con- stitutes the transcendental ground of the possibility of all modes of knowledge whatsoever -- of those that are pure a priori no less than of those that are empirical -- the repro- ductive synthesis of the imagination is to be counted among the transcendental acts of the mind. We shall therefore entitle this faculty the transcendental faculty of imagination. 3. The Synthesis of Recognition in a Concept If we were not conscious that what we think is the same as what we thought a moment before, all reproduction in the series of representations would be useless. For it would in its present state be a new representation which would not in any way belong to the act whereby it was to be gradually gener- P 134 ated. The manifold of the representation would never, there- fore, form a whole, since it would lack that unity which only consciousness can impart to it. If, in counting, I forget that the units, which now hover before me, have been added to one another in succession, I should never know that a total is being produced through this successive addition of unit to unit, and so would remain ignorant of the number. For the concept of the number is nothing but the consciousness of this unity of synthesis. The word 'concept' might of itself suggest this remark. For this unitary consciousness is what combines the mani- fold, successively intuited, and thereupon also reproduced, into one representation. This consciousness may often be only faint, so that we do not connect it with the act itself, that is, not in any direct manner with the generation of the repre- sentation, but only with the outcome [that which is thereby represented]. But notwithstanding these variations, such con- sciousness, however indistinct, must always be present; with- out it, concepts, and therewith knowledge of objects, are altogether impossible. At this point we must make clear to ourselves what we mean by the expression 'an object of representations'. We have stated above that appearances are themselves nothing but sensible representations, which, as such and in themselves, must not be taken as objects capable of existing outside our power of representation. What, then, is to be understood when we speak of an object corresponding to, and consequently also distinct from, our knowledge? It is easily seen that this object must be thought only as something in general = x, since outside our knowledge we have nothing which we could set over against this knowledge as corresponding to it. Now we find that our thought of the relation of all know- ledge to its object carries with it an element of necessity; the object is viewed as that which prevents our modes of know- ledge from being haphazard or arbitrary, and which deter- mines them a priori in some definite fashion. For in so far as they are to relate to an object, they must necessarily agree P 135 with one another, that is, must possess that unity which con- stitutes the concept of an object. But it is clear that, since we have to deal only with the manifold of our representations, and since that x (the object) which corresponds to them is nothing to us -- being, as it is, something that has to be distinct from all our representations -- the unity which the object makes necessary can be nothing else than the formal unity of consciousness in the synthesis of the manifold of representations. It is only when we have thus produced synthetic unity in the manifold of intuition that we are in a position to say that we know the object. But this unity is impossible if the intuition cannot be generated in accord- ance with a rule by means of such a function of synthesis as makes the reproduction of the manifold a priori necessary, and renders possible a concept in which it is united. Thus we think a triangle as an object, in that we are conscious of the combination of three straight lines according to a rule by which such an intuition can always be represented. This unity of rule determines all the manifold, and limits it to conditions which make unity of apperception possible. The concept of this unity is the representation of the object = x, which I think through the predicates, above mentioned, of a triangle. All knowledge demands a concept, though that concept may, indeed, be quite imperfect or obscure. But a concept is always, as regards its form, something universal which serves as a rule. The concept of body, for instance, as the unity of the manifold which is thought through it, serves as a rule in our knowledge of outer appearances. But it can be a rule for intuitions only in so far as it represents in any given appearances the necessary reproduction of their manifold, and thereby the synthetic unity in our consciousness of them. The concept of body, in the perception of something outside us, necessitates the representation of extension, and there- with representations of impenetrability, shape, etc. All necessity, without exception, is grounded in a tran- scendental condition. There must, therefore, be a transcend- ental ground of the unity of consciousness in the synthesis of the manifold of all our intuitions, and consequently also of the concepts of objects in general, and so of all objects of experience, a ground without which it would be impossible P 136 to think any object for our intuitions; for this object is no more than that something, the concept of which expresses such a necessity of synthesis. This original and transcendental condition is no other than transcendental apperception. Consciousness of self according to the determinations of our state in inner percep- tion is merely empirical, and always changing. No fixed and abiding self can present itself in this flux of inner appear- ances. Such consciousness is usually named inner sense, or empirical apperception. What has necessarily to be repre- sented as numerically identical cannot be thought as such through empirical data. To render such a transcendental presupposition valid, there must be a condition which precedes all experience, and which makes experience itself possible. There can be in us no modes of knowledge, no connection or unity of one mode of knowledge with another, without that unity of consciousness which precedes all data of intuitions, and by relation to which representation of objects is alone possible. This pure original unchangeable consciousness I shall name transcendental apperception. That it deserves this name is clear from the fact that even the purest objective unity, namely, that of the a priori concepts (space and time), is only possible through relation of the intuitions to such unity of consciousness. The numerical unity of this appercep- tion is thus the a priori ground of all concepts, just as the manifoldness of space and time is the a priori ground of the intuitions of sensibility. This transcendental unity of apperception forms out of all possible appearances, which can stand alongside one another in one experience, a connection of all these repre- sentations according to laws. For this unity of consciousness would be impossible if the mind in knowledge of the manifold could not become conscious of the identity of function whereby it synthetically combines it in one knowledge. The original and necessary consciousness of the identity of the self is thus at the same time a consciousness of an equally necessary unity of the synthesis of all appearances according to concepts, that P 137 is, according to rules, which not only make them necessarily reproducible but also in so doing determine an object for their intuition, that is, the concept of something wherein they are necessarily interconnected. For the mind could never think its identity in the manifoldness of its representations, and indeed think this identity a priori, if it did not have before its eyes the identity of its act, whereby it subordinates all synthesis of apprehension (which is empirical) to a transcend- ental unity, thereby rendering possible their interconnection according to a priori rules. Now, also, we are in a position to determine more ade- quately our concept of an object in general. All representations have, as representations, their object, and can themselves in turn become objects of other representations. Appearances are the sole objects which can be given to us immediately, and that in them which relates immediately to the object is called intuition. But these appearances are not things in themselves; they are only representations, which in turn have their object -- an object which cannot itself be intuited by us, and which may, therefore, be named the non-empirical, that is, transcend- ental object = x. The pure concept of this transcendental object, which in reality throughout all our knowledge is always one and the same, is what can alone confer upon all our empirical con- cepts in general relation to an object, that is, objective reality. This concept cannot contain any determinate intuition, and therefore refers only to that unity which must be met with in any manifold of knowledge which stands in relation to an object. This relation is nothing but the necessary unity of consciousness, and therefore also of the synthesis of the mani- fold, through a common function of the mind, which com- bines it in one representation. Since this unity must be re- garded as necessary a priori -- otherwise knowledge would be without an object -- the relation to a transcendental object, that is, the objective reality of our empirical knowledge, rests on the transcendental law, that all appearances, in so far as through them objects are to be given to us, must stand under those a priori rules of synthetical unity whereby the inter- P 138 relating of these appearances in empirical intuition is alone possible. In other words, appearances in experience must stand under the conditions of the necessary unity of apper- ception, just as in mere intuition they must be subject to the formal conditions of space and of time. Only thus can any knowledge become possible at all. 4.Preliminary Explanation of the Possibility of the Categories, as Knowledge a priori There is one single experience in which all perceptions are represented as in thoroughgoing and orderly connection, just as there is only one space and one time in which all modes of appearance and all relation of being or not being occur. When we speak of different experiences, we can refer only to the various perceptions, all of which, as such, belong to one and the same general experience. This thoroughgoing synthetic unity of perceptions is indeed the form of experience; it is nothing else than the synthetic unity of appearances in accordance with concepts. Unity of synthesis according to empirical concepts would be altogether accidental, if these latter were not based on a transcendental ground of unity. Otherwise it would be possible for appearances to crowd in upon the soul, and yet to be such as would never allow of experience. Since connection in accord- ance with universal and necessary laws would be lacking, all relation of knowledge to objects would fall away. The appear- ances might, indeed, constitute intuition without thought, but not knowledge; and consequently would be for us as good as nothing. The a priori conditions of a possible experience in general are at the same time conditions of the possibility of objects of experience. Now I maintain that the categories, above cited, are nothing but the conditions of thought in a possible experience, just as space and time are the conditions of in- tuition for that same experience. They are fundamental con- cepts by which we think objects in general for appearances, and have therefore a priori objective validity. This is exactly what we desired to prove. P 139 But the possibility, indeed the necessity, of these cate- gories rests on the relation in which our entire sensibility, and with it all possible appearances, stand to original apper- ception. In original apperception everything must necessarily conform to the conditions of the thoroughgoing unity of self- consciousness, that is, to the universal functions of synthesis, namely, of that synthesis according to concepts in which alone apperception can demonstrate a priori its complete and necessary identity. Thus the concept of a cause is nothing but a synthesis (of that which follows in the time-series, with other appearances) according to concepts; and without such unity, which has its a priori rule, and which subjects the appear- ances to itself, no thoroughgoing, universal, and therefore necessary, unity of consciousness would be met with in the manifold of perceptions. These perceptions would not then belong to any experience, consequently would be without an object, merely a blind play of representations, less even than a dream. All attempts to derive these pure concepts of understand- ing from experience, and so to ascribe to them a merely em- pirical origin, are entirely vain and useless. I need not insist upon the fact that, for instance, the concept of a cause involves the character of necessity, which no experience can yield. Experience does indeed show that one appearance customarily follows upon another, but not that this sequence is necessary, nor that we can argue a priori and with complete universality from the antecedent, viewed as a condition, to the consequent. But as regards the empirical rule of association, which we must postulate throughout when we assert that everything in the series of events is so subject to rule that nothing ever happens save in so far as something precedes it on which it universally follows -- upon what I ask, does this rule, as a law of nature, rest? How is this association itself possible? The ground of the possibility of the association of the manifold, so far as it lies in the object, is named the affinity of the manifold. I therefore ask, how are we to make comprehensible to our- selves the thoroughgoing affinity of appearances, whereby they stand and must stand under unchanging laws? On my principles it is easily explicable. All possible ap- pearances, as representations, belong to the totality of a pos- P 140 sible self-consciousness. But as self-consciousness is a tran- scendental representation, numerical identity is inseparable from it, and is a priori certain. For nothing can come to our knowledge save in terms of this original apperception. Now, since this identity must necessarily enter into the synthesis of all the manifold of appearances, so far as the synthesis is to yield empirical knowledge, the appearances are subject to a priori conditions, with which the synthesis of their apprehen- sion must be in complete accordance. The representation of a universal condition according to which a certain manifold can be posited in uniform fashion is called a rule, and, when it must be so posited, a law. Thus all appearances stand in thoroughgoing connection according to necessary laws, and therefore in a transcendental affinity, of which the empirical is a mere consequence. That nature should direct itself according to our sub- jective ground of apperception, and should indeed depend upon it in respect of its conformity to law, sounds very strange and absurd. But when we consider that this nature is not a thing in itself but is merely an aggregate of appearances, so many representations of the mind, we shall not be surprised that we can discover it only in the radical faculty of all our knowledge, namely, in transcendental apperception, in that unity on account of which alone it can be entitled object of all possible experience, that is, nature. Nor shall we be surprised that just for this very reason this unity can be known a priori, and therefore as necessary. Were the unity given in itself in- dependently of the first sources of our thought, this would never be possible. We should not then know of any source from which we could obtain the synthetic propositions assert- ing such a universal unity of nature. For they would then have to be derived from the objects of nature themselves; and as this could take place only empirically, none but a merely accidental unity could be obtained, which would fall far short of the necessary interconnection that we have in mind when we speak of nature. P 141 DEDUCTION OF THE PURE CONCEPTS OF UNDERSTANDING Section 3 THE RELATION OF THE UNDERSTANDING TO OBJECTS IN GENERAL, AND THE POSSIBILITY OF KNOWING THEM A PRIORI What we have expounded separately and singly in the preceding section, we shall now present in systematic inter- connection. There are three subjective sources of knowledge upon which rests the possibility of experience in general and of knowledge of its objects -- sense, imagination, and appercep- tion. Each of these can be viewed as empirical, namely, in its application to given appearances. But all of them are likewise a priori elements or foundations, which make this empirical employment itself possible. Sense represents appearances em- pirically in perception, imagination in association (and repro- duction), apperception in the empirical consciousness of the identity of the reproduced representations with the appear- ances whereby they were given, that is, in recognition. But all perceptions are grounded a priori in pure intuition (in time, the form of their inner intuition as representations), association in pure synthesis of imagination, and empirical consciousness in pure apperception, that is, in the thorough- going identity of the self in all possible representations. If, now, we desire to follow up the inner ground of this connection of the representations to the point upon which they have all to converge in order that they may therein for the first time acquire the unity of knowledge necessary for a possible experience, we must begin with pure appercep- tion. Intuitions are nothing to us, and do not in the least concern us if they cannot be taken up into consciousness, in which they may participate either directly or indirectly. In this way alone is any knowledge possible. We are conscious a priori of the complete identity of the self in respect of all representations which can even belong to our knowledge, as being a necessary condition of the possibility of all representa- P 142 tions. For in me they can represent something only in so far as they belong with all others to one consciousness, and therefore must be at least capable of being so connected. This principle holds a priori, and may be called the tran- scendental principle of the unity of all that is manifold in our representations, and consequently also in intuition. Since this unity of the manifold in one subject is synthetic, pure apper- ception supplies a principle of the synthetic unity of the mani- fold in all possible intuition. This synthetic unity presupposes or includes a synthesis, and if the former is to be a priori necessary, the synthesis must also be a priori. The transcendental unity of apperception thus relates to the pure synthesis of imagination, as an a priori condition of the possibility of all combination of the manifold in one knowledge. This proposition is of great importance and calls for careful consideration. All representations have a necessary relation to a possible empirical consciousness. For if they did not have this, and if it were altogether impossible to become conscious of them, this would practically amount to the admission of their non-existence. But all empirical consciousness has a necessary relation to a tran- scendental consciousness which precedes all special experience, namely, the consciousness of myself as original apperception. It is therefore absolutely necessary that in my knowledge all conscious- ness should belong to a single consciousness, that of myself. Here, then, is a synthetic unity of the manifold (of consciousness), which is known a priori, and so yields the ground for synthetic a priori propositions which concern pure thought, just as do space and time for the propositions which refer to the form of pure intuition. The synthetic proposition, that all the variety of empirical consciousness must be combined in one single self-consciousness, is the abso- lutely first and synthetic principle of our thought in general. But it must not be forgotten that the bare representation 'I' in relation to all other representations (the collective unity of which it makes possible) is transcendental consciousness. Whether this representa- tion is clear (empirical consciousness) or obscure, or even whether it ever actually occurs, does not here concern us. But the possibility of the logical form of all knowledge is necessarily conditioned by relation to this apperception as a faculty. P 142 But only the productive synthesis of the P 143 imagination can take place a priori; the reproductive rests upon empirical conditions. Thus the principle of the necessary unity of pure (productive) synthesis of imagination, prior to apperception, is the ground of the possibility of all know- ledge, especially of experience. We entitle the synthesis of the manifold in imagination transcendental, if without distinction of intuitions it is directed exclusively to the a priori combination of the manifold; and the unity of this synthesis is called transcendental, if it is repre- sented as a priori necessary in relation to the original unity of apperception. Since this unity of apperception underlies the possibility of all knowledge, the transcendental unity of the synthesis of imagination is the pure form of all possible knowledge; and by means of it all objects of possible experi- ence must be represented a priori. The unity of apperception in relation to the synthesis of imagination is the understanding; and this same unity, with reference to the transcendental synthesis of the imagination, the pure understanding. In the understanding there are then pure a priori modes of knowledge which contain the neces- sary unity of the pure synthesis of imagination in respect of all possible appearances. These are the categories, that is, the pure concepts of understanding. The empirical faculty of know- ledge in man must therefore contain an understanding which relates to all objects of the senses, although only by means of intuition and of its synthesis through imagination. All appear- ances, as data for a possible experience, are subject to this understanding. This relation of appearances to possible ex- perience is indeed necessary, for otherwise they would yield no knowledge and would not in any way concern us. We have, therefore, to recognise that pure understanding, by means of the categories, is a formal and synthetic principle of all ex- periences, and that appearances have a necessary relation to the understanding. We will now, starting from below, namely, with the em- pirical, strive to make clear the necessary connection in which understanding, by means of the categories, stands to appear- ances. What is first given to us is appearance. When combined with consciousness, it is called perception. (Save through its P 144 relation to a consciousness that is at least possible, appear- ance could never be for us an object of knowledge, and so would be nothing to us; and since it has in itself no objective reality, but exists only in being known, it would be nothing at all. ) Now, since every appearance contains a manifold, and since different perceptions therefore occur in the mind separately and singly, a combination of them, such as they cannot have in sense itself, is demanded. There must therefore exist in us an active faculty for the synthesis of this manifold. To this faculty I give the title, imagination. Its action, when immediately directed upon perceptions, I entitle apprehen- sion. Since imagination has to bring the manifold of intuition into the form of an image, it must previously have taken the impressions up into its activity, that is, have apprehended them. But it is clear that even this apprehension of the manifold would not by itself produce an image and a connection of the impressions, were it not that there exists a subjective ground which leads the mind to reinstate a preceding perception alongside the subsequent perception to which it has passed, and so to form whole series of perceptions. This is the repro- ductive faculty of imagination, which is merely empirical. If, however, representations reproduced one another in any order, just as they happened to come together, this would not lead to any determinate connection of them, but only to acci- dental collocations; and so would not give rise to any know- ledge. Their reproduction must, therefore, conform to a rule, in accordance with which a representation connects in the imagination with some one representation in preference to another. This subjective and empirical ground of repro- duction according to rules is what is called the association of representations. Psychologists have hitherto failed to realise that imagination is a necessary ingredient of perception itself. This is due partly to the fact that that faculty has been limited to reproduction, partly to the belief that the senses not only supply impressions but also com- bine them so as to generate images of objects. For that purpose some- thing more than the mere receptivity of impressions is undoubtedly required, namely, a function for the synthesis of them. P 144 Now if this unity of association had not also an objective P 145 ground which makes it impossible that appearances should be apprehended by the imagination otherwise than under the condition of a possible synthetic unity of this apprehension, it would be entirely accidental that appearances should fit into a connected whole of human knowledge. For even though we should have the power of associating perceptions, it would remain entirely undetermined and accidental whether they would themselves be associable; and should they not be associ- able, there might exist a multitude of perceptions, and indeed an entire sensibility, in which much empirical consciousness would arise in my mind, but in a state of separation, and without belonging to a consciousness of myself. This, however, is im- possible. For it is only because I ascribe all perceptions to one consciousness (original apperception) that I can say of all per- ceptions that I am conscious of them. There must, therefore, be an objective ground (that is, one that can be comprehended a priori, antecedently to all empirical laws of the imagination) upon which rests the possibility, nay, the necessity, of a law that extends to all appearances -- a ground, namely, which constrains us to regard all appearances as data of the senses that must be associable in themselves and subject to universal rules of a thoroughgoing connection in their reproduction. This objective ground of all association of appearances I entitle their affinity. It is nowhere to be found save in the principle of the unity of apperception, in respect of all know- ledge which is to belong to me. According to this principle all appearances, without exception, must so enter the mind or be apprehended, that they conform to the unity of appercep- tion. Without synthetic unity in their connection, this would be impossible; and such synthetic unity is itself, therefore, objectively necessary. The objective unity of all empirical consciousness in one consciousness, that of original apperception, is thus the neces- sary condition of all possible perception; and [this being recog- nised we can prove that] the affinity of all appearances, near or remote, is a necessary consequence of a synthesis in imagina- tion which is grounded a priori on rules. Since the imagination is itself a faculty of a priori syn- thesis, we assign to it the title, productive imagination. In so far as it aims at nothing but necessary unity in the synthesis of P 146 what is manifold in appearance, it may be entitled the tran- scendental function of imagination. That the affinity of appear- ances, and with it their association, and through this, in turn, their reproduction according to laws, and so [as involving these various factors] experience itself, should only be possible by means of this transcendental function of imagination, is indeed strange, but is none the less an obvious consequence of the preceding argument. For without this transcendental func- tion no concepts would together make up a unitary experience. The abiding and unchanging 'I' (pure apperception) forms the correlate of all our representations in so far as it is to be at all possible that we should become conscious of them. All consciousness as truly belongs to an all-comprehensive pure apperception, as all sensible intuition, as representation, does to a pure inner intuition, namely, to time. It is this apperception which must be added to pure imagination, in order to render its function intellectual. For since the syn- thesis of imagination connects the manifold only as it appears in intuition, as, for instance, in the shape of a triangle, it is, though exercised a priori, always in itself sensible. And while concepts, which belong to the understanding, are brought into play through relation of the manifold to the unity of apper- ception, it is only by means of the imagination that they can be brought into relation to sensible intuition. A pure imagination, which conditions all a priori know- ledge, is thus one of the fundamental faculties of the human soul. By its means we bring the manifold of intuition on the one side, into connection with the condition of the necessary unity of pure apperception on the other. The two extremes, namely sensibility and understanding, must stand in neces- sary connection with each other through the mediation of this transcendental function of imagination, because otherwise the former, though indeed yielding appearances, would supply no objects of empirical knowledge, and consequently no experi- ence. Actual experience, which is consitituted by apprehension, association (reproduction), and finally recognition of appear- ances, contains in recognition, the last and highest of these P 147 merely empirical elements of experience, certain concepts which render possible the formal unity of experience, and therewith all objective validity (truth) of empirical knowledge. These grounds of the recognition of the manifold, so far as they concern solely the form of an experience in general, are the categories. Upon them is based not only all formal unity in the [transcendental] synthesis of imagination, but also, thanks to that synthesis, all its empirical employment (in recogni- tion, reproduction, association, apprehension) in connection with the appearances. For only by means of these funda- mental concepts can appearances belong to knowledge or even to our consciousness, and so to ourselves. Thus the order and regularity in the appearances, which we entitle nature, we ourselves introduce. We could never find them in appearances, had no we ourselves, or the nature of our mind, originally set them there. For this unity of nature has to be a necessary one, that is, has to be an a priori certain unity of the connection of appearances; and such synthetic unity could not be established a priori if there were not sub- jective grounds of such unity contained a priori in the original cognitive powers of our mind, and if these subjective condi- tions, inasmuch as they are the grounds of the possibility of knowing any object whatsoever in experience, were not at the same time objectively valid. We have already defined the understanding in various different ways: as a spontaneity of knowledge (in distinction from the receptivity of sensibility), as a power of thought, as a faculty of concepts, or again of judgments. All these defini- tions, when they are adequately understood, are identical. We may now characterise it as the faculty of rules. This dis- tinguishing mark is more fruitful, and approximates more closely to its essential nature. Sensibility gives us forms (of intuition), but understanding gives us rules. The latter is always occupied in investigating appearances, in order to detect some rule in them. Rules, so far as they are objective, and therefore necessarily depend upon the knowledge of the object, are called laws. Although we learn many laws through P 148 experience, they are only special determinations of still higher laws, and the highest of these, under which the others all stand, issue a priori from the understanding itself. They are not borrowed from experience; on the contrary, they have to confer upon appearances their conformity to law, and so to make experience possible. Thus the understanding is some- thing more than a power of formulating rules through com- parison of appearances; it is itself the lawgiver of nature. Save through it, nature, that is, synthetic unity of the mani- fold of appearances according to rules, would not exist at all (for appearances, as such, cannot exist outside us -- they exist only in our sensibility); and this nature, as object of knowledge in an experience, with everything which it may contain, is only possible in the unity of apperception. The unity of apperception is thus the transcendental ground of the necessary conformity to law of all appearances in one ex- perience. This same unity of apperception in respect to a manifold of representations (determining it out of a unity) acts as the rule, and the faculty of these rules is the under- standing. All appearances, as possible experiences, thus lie a priori in the understanding, and receive from it their formal possibility, just as, in so far as they are mere in- tuitions, they lie in the sensibility, and are, as regards their form, only possible through it. However exaggerated and absurd it may sound, to say that the understanding is itself the source of the laws of nature, and so of its formal unity, such an assertion is none the less correct, and is in keeping with the object to which it refers, namely, experience. Certainly, empirical laws, as such, can never derive their origin from pure understanding. That is as little possible as to understand completely the inexhaust- ible multiplicity of appearances merely by reference to the pure form of sensible intuition. But all empirical laws are only special determinations of the pure laws of understanding, under which, and according to the norm of which, they first become possible. Through them appearances take on an orderly character, just as these same appearances, despite P 149 the differences of their empirical form, must none the less always be in harmony with the pure form of sensibility. Pure understanding is thus in the categories the law of the synthetic unity of all appearances, and thereby first and originally makes experience, as regards its form, possible. This is all that we were called upon to establish in the tran- scendental deduction of the categories, namely, to render comprehensible this relation of understanding to sensibility, and, by means of sensibility, to all objects of experience. The objective validity of the pure a priori concepts is thereby made intelligible, and their origin and truth determined. Summary Representation of the Correctness of this Deduction of the Pure Concepts of Understanding, and of its being the only Deduction possible If the objects with which our knowledge has to deal were things in themselves, we could have no a priori concepts of them. For from what source could we obtain the concepts? If we derived them from the object (leaving aside the question how the object could become known to us), our concepts would be merely empirical, not a priori. And if we derived them from the self, that which is merely in us could not determine the character of an object distinct from our representations, that is, could not be a ground why a thing should exist character- ised by that which we have in our thought, and why such a representation should not, rather, be altogether empty. But if, on the other hand, we have to deal only with appearances, it is not merely possible, but necessary, that certain a priori concepts should precede empirical knowledge of objects. For since a mere modification of our sensibility can never be met with outside us, the objects, as appearances, constitute an object which is merely in us. Now to assert in this manner, that all these appearances, and consequently all objects with which we can occupy ourselves, are one and all in me, that is, are determinations of my identical self, is only another way of saying that there must be a complete unity of them in one and the same apperception. But this unity of possible consciousness also constitutes the form of all knowledge of objects; through it the manifold is thought as belonging to a P 150 single object. Thus the mode in which the manifold of sensible representation (intuition) belongs to one consciousness pre- cedes all knowledge of the object as the intellectual form of such knowledge, and itself constitutes a formal a priori know- ledge of all objects, so far as they are thought (categories). The synthesis of the manifold through pure imagination, the unity of all representations in relation to original apper- ception, precede all empirical knowledge. Pure concepts of understanding are thus a priori possible, and, in relation to experience, are indeed necessary; and this for the reason that our knowledge has to deal solely with appearances, the possibility of which lies in ourselves, and the connection and unity of which (in the representation of an object) are to be met with only in ourselves. Such connection and unity must therefore precede all experience, and are required for the very possibility of it in its formal aspect. From this point of view, the only feasible one, our deduction of the categories has been developed. P 151 DEDUCTION OF THE PURE CONCEPTS OF THE UNDERSTANDING Section 2 TRANSCENDENTAL DEDUCTION OF THE PURE CONCEPTS OF THE UNDERSTANDING $15 The Possibility of Combination in General THE manifold of representations can be given in an intuition which is purely sensible, that is, nothing but receptivity; and the form of this intuition can lie a priori in our faculty of representation, without being anything more than the mode in which the subject is affected. But the combination (conjunctio) of a manifold in general can never come to us through the senses, and cannot, therefore, be already contained in the pure form of sensible intuition. For it is an act of spontaneity of the faculty of representation; and since this faculty, to distinguish it from sensibility, must be entitled understanding, all com- bination -- be we conscious of it or not, be it a combination of the manifold of intuition, empirical or non-empirical, or of various concepts -- is an act of the understanding. To this act the general title 'synthesis' may be assigned, as indicating that we cannot represent to ourselves anything as combined in the object which we have not ourselves previously combined, and that of all representations combination is the only one which P 152 cannot be given through objects. Being an act of the self- activity of the subject, it cannot be executed save by the sub- ject itself. It will easily be observed that this action is originally one and is equipollent for all combination, and that is dis- solution, namely, analysis, which appears to be its opposite, yet always presupposes it. For where the understanding has not previously combined, it cannot dissolve, since only as having been combined by the understanding can anything that allows of analysis be given to the faculty of representation. But the concept of combination includes, besides the con- cept of the manifold and of its synthesis, also the concept of the unity of the manifold. Combination is representation of the synthetic unity of the manifold. The representation of this unity cannot, therefore, arise out of the combination. On the contrary, it is what, by adding itself to the representation of the manifold, first makes possible the concept of the combina- tion. This unity, which precedes a priori all concepts of com- bination, is not the category of unity ($10); for all categories are grounded in logical functions of judgment, and in these functions combination, and therefore unity of given concepts, is already thought. Thus the category already presupposes combination. We must therefore look yet higher for this unity (as qualitative, $12), namely in that which itself contains the ground of the unity of diverse concepts in judgment, and there- fore of the possibility of the understanding, even as regards its logical employment. $16 The Original Synthetic Unity of Apperception It must be possible for the 'I think' to accompany all my representations; for otherwise something would be represented P 153 in me which could not be thought at all, and that is equivalent to saying that the representation would be impossible, or at least would be nothing to me. P 152 Whether the representations are in themselves identical, and whether, therefore, one can be analytically thought through the other, is not a question that here arises. The consciousness of the one, when the manifold is under consideration, has always to be dis- tinguished from the consciousness of the other; and it is with the synthesis of this (possible) consciousness that we are here alone concerned. P 153 That representation which can be given prior to all thought is entitled intuition. All the manifold of intuition has, therefore, a necessary relation to the 'I think' in the same subject in which this manifold is found. But this representation is an act of spontaneity, that is, it cannot be regarded as belonging to sensibility. I call it pure apperception, to distinguish it from empirical apperception, or, again, origninal apperception, because it is that self-consious- ness which, while generating the representation 'I think' (a representation which must be capable of accompanying all other representations, and which in all consciousness is one and the same), cannot itself be accompanied by any further repre- sentation. The unity of this apperception I likewise entitle the transcendental unity of self-consciousness, in order to indicate the possibility of a priori knowledge arising from it. For the manifold representations, which are given in an intuition, would not be one and all my representations, if they did not all belong to one self-consciousness. As my representa- tions (even if I am not conscious of them as such) they must conform to the condition under which alone they can stand together in one universal self-consciousness, because otherwise they would not all without exception belong to me. From this original combination many consequences follow. This thoroughgoing identity of the apperception of a manifold which is given in intuition contains a synthesis of representations, and is possible only through the conscious- ness of this synthesis. For the empirical consciousness, which accompanies different representations, is in itself diverse and without relation to the identity of the subject. That relation comes about, not simply through my accompanying each re- presentation with consciousness, but only in so far as I conjoin one representation with another, and am conscious of the syn- thesis of them. Only in so far, therefore, as I can unite a manifold of given representations in one consciousness, is it possible for me to represent to myself the identity of the con- sciousness in [i.e. throughout] these representations. In other P 154 words, the analytic unity of apperception is possible only under the presupposition of a certain synthetic unity. The thought that the representations given in intuition one and all belong to me, is therefore equivalent to the thought that I unite them in one self-consciousness, or can at least so unite them; and although this thought is not itself the consciousness of the synthesis of the representations, it pre- supposes the possibility of that synthesis. In other words, only in so far as I can grasp the manifold of the representations in one consciousness, do I call them one and all mine. For other- wise I should have as many-coloured and diverse a self as I have representations of which I am conscious to myself. Syn- thetic unity of the manifold of intuitions, as generated a - priori, is thus the ground of the identity of apperception itself, which precedes a priori all my determinate thought. Com- bination does not, however, lie in the objects, and cannot be borrowed from them, and so, through perception, first taken up into the understanding. On the contrary, it is an affair of the understanding alone, which itself is nothing but the faculty of combining a priori, and of bringing the manifold of given representations under the unity of apperception. The principle of apperception is the highest principle in the whole sphere of human knowledge. This principle of the necessary unity of apperception is ++ The analytic unity of consciousness belongs to all general con- cepts, as such. If, for instance, I think red in general, I thereby repre- sent to myself a property which (as a characteristic) can be found in something, or can he combined with other representations; that is, only by means of a presupposed possible synthetic unity can I repre- sent to myself the analytic unity. A representation which is to be thought as common to different representations is regarded as be- longing to such as have, in addition to it, also something different. Consequently it must previously be thought in synthetic unity with other (though, it may be, only possible) representations, before I can think in it the analytic unity of consciousness, which makes it a con- ceptus communis. The synthetic unity of apperception is therefore that highest point, to which we must ascribe all employment of the understanding, even the whole of logic, and conformably therewith, transcendental philosophy. Indeed this faculty of apperception is the understanding itself. P 155 itself, indeed, an identical, and therefore analytic, proposi- tion; nevertheless it reveals the necessity of a synthesis of the manifold given in intuition, without which the thoroughgoing identity of self-consciousness cannot be thought. For through the 'I', as simple representation, nothing manifold is given; only in intuition, which is distinct from the 'I', can a manifold be given; and only through combination in one conscious- ness can it be thought. An understanding in which through self-consciousness all the manifold would eo ipso be given, would be intuitive; our understanding can only think, and for intuition must look to the senses. I am conscious of the self as identical in respect of the manifold of representations that are given to me in an intuition, because I call them one and all my representations, and so apprehend them as con- stituting one intuition. This amounts to saying, that I am conscious to myself a priori of a necessary synthesis of re- presentations -- to be entitled the original synthetic unity of apperception -- under which all representations that are given to me must stand, but under which they have also first to be brought by means of a synthesis. $17 The Principle of the Synthetic Unity is the Supreme Principle of all Employment of the Understanding The supreme principle of the possibility of all intuition in its relation to sensibility is, according to the Transcendental Aesthetic, that all the manifold of intuition should be subject to the formal conditions of space and time. The supreme prin- ciple of the same possibility, in its relation to understanding, is that all the manifold of intuition should be subject to con- ditions of the original synthetic unity of apperception. Space and time, and all their parts, are intuitions, and are, therefore, with the manifold which they contain, singular representa- tions (vide the Transcendental Aesthetic). Consequently they are not mere concepts through which one and the same consciousness is found to be contained in a number of representations. On the con- trary, through them many representations are found to be contained in one representation, and in the consciousness of that representa- tion ; and they are thus composite. The unity of that consciousness P 156n is therefore synthetic and yet is also original. The singularity of such intuitions is found to have important consequences (vide $25). P 155 In so P 156 far as the manifold representations of intuition are given to us, they are subject to the former of these two principles; in so far as they must allow of being combined in one consciousness, they are subject to the latter. For without such combination nothing can be thought or known, since the given repre- sentations would not have in common the act of the apper- ception 'I think', and so could not be apprehended together in knowledge. This knowledge consists in the determinate re- lation of given representations to an object; and an object is that in the concept of which the manifold of a given intuition is united. Now all unification of representations demands unity of consciousness in the synthesis of them. Consequently it is the unity of consciousness that alone constitutes the relation of representations to an object, and therefore their objective validity and the fact that they are modes of know- ledge; and upon it therefore rests the very possibility of the understanding. The first pure knowledge of understanding, then, upon which all the rest of its employment is based, and which also at the same time is completely independent of all conditions of sensible intuition, is the principle of the original synthetic unity of apperception. Thus the mere form of outer sensible intuition, space, is not yet [by itself] knowledge; it supplies only the manifold of a priori intuition for a possible know- ledge. To know anything in space (for instance, a line), I must draw it, and thus synthetically bring into being a de- terminate combination of the given manifold, so that the unity of this act is at the same time the unity of consciousness (as in the concept of a line); and it is through this unity of con- sciousness that an object (a determinate space) is first known. The synthetic unity of consciousness is, therefore, an objective condition of all knowledge. It is not merely a condition that I myself require in knowing an object, but is a condition under which every intuition must stand in order to become an object for me. For otherwise, in the absence of this P 157 synthesis, the manifold would not be united in one con- sciousness. Although this proposition makes synthetic unity a con- dition of all thought, it is, as already stated, itself analytic. For it says no more than that all my representations in any given intuition must be subject to that condition under which alone I can ascribe them to the identical self as my representa- tions, and so can comprehend them as synthetically com- bined in one apperception through the general expression, 'I think'. This principle is not, however, to be taken as applying to every possible understanding, but only to that understand- ing through whose pure apperception, in the representation 'I am', nothing manifold is given. An understanding which through its self-consciousness could supply to itself the mani- fold of intuition -- an understanding, that is to say, through whose representation the objects of the representation should at the same time exist -- would not require, for the unity of consciousness, a special act of synthesis of the manifold. For the human understanding, however, which thinks only, and does not intuit, that act is necessary. It is indeed the first principle of the human understanding, and is so indispensable to it that we cannot form the least conception of any other possible understanding, either of such as is itself intuitive or of any that may possess an underlying mode of sensible in- tuition which is different in kind from that in space and time. $18 The Objective Unity of Self-Consciousness The transcendental unity of apperception is that unity through which all the manifold given in an intuition is united in a concept of the object. It is therefore entitled objective, and must be distinguished from the subjective unity of con- sciousness, which is a determination of inner sense -- through which the manifold of intuition for such [objective] combina- tion is empirically given. Whether I can become empirically conscious of the manifold as simultaneous or as successive depends on circumstances or empirical conditions. Therefore P 158 the empirical unity of consciousness, through association of representations, itself concerns an appearance, and is wholly contingent. But the pure form of intuition in time, merely as intuition in general, which contains a given manifold, is subject to the original unity of consciousness, simply through the necessary relation of the manifold of the intuition to the one 'I think', and so through the pure synthesis of understanding which is the a priori underlying ground of the empirical synthesis. Only the original unity is objectively valid; the empirical unity of apperception, upon which we are not here dwelling, and which besides is merely derived from the former under given conditions in concreto, has only subjective validity. To one man, for instance, a certain word suggests one thing, to another some other thing; the unity of consciousness in that which is empirical is not, as regards what is given, necessarily and universally valid. $19 The Logical Form of all Judgments consists in the Objective Unity of the Apperception of the Concepts which they contain I have never been able to accept the interpretation which logicians give of judgment in general. It is, they declare, the representation of a relation between two concepts. I do not here dispute with them as to what is defective in this interpretation -- that in any case it applies only to categorical, not to hypothetical and disjunctive judgments (the two latter containing a relation not of concepts but of judgments), an oversight from which many troublesome consequences have followed. I need only point out that the definition does not determine in what the asserted relation consists. The lengthy doctrine of the four syllogistic figures concerns categorical syllogisms only; and although it is indeed nothing more than an artificial method of securing, through the surreptitious introduction of immediate inferences (consequentiae immediatae) among the premisses of a pure syllogism, the appearance that there are more kinds of inference than that of the first figure, this would hardly have met with such remarkable acceptance, had not its authors succeeded in bringing categorical judgments into such P 159n exclusive respect, as being those to which all others must allow of being reduced -- teaching which, as indicated in $9, is none the less erroneous. P 159 But if I investigate more precisely the relation of the given modes of knowledge in any judgment, and distinguish it, as belonging to the understanding, from the relation accord- ing to laws of the reproductive imagination, which has only subjective validity, I find that a judgment is nothing but the manner in which given modes of knowledge are brought to the objective unity of apperception. This is what is intended by the copula 'is'. It is employed to distinguish the objective unity of given representations from the sub- jective. It indicates their relation to original apperception, and its necessary unity. It holds good even if the judgment is itself empirical, and therefore contingent, as, for example, in the judgment, 'Bodies are heavy'. I do not here assert that these representations necessarily belong to one another in the empirical intuition, but that they belong to one another in virtue of the necessary unity of apperception in the synthesis of intuitions, that is, according to principles of the object- ive determination of all representations, in so far as know- ledge can be acquired by means of these representations -- principles which are all derived from the fundamental prin- ciple of the transcendental unity of apperception. Only in this way does there arise from this relation a judgment, that is, a relation which is objectively valid, and so can be adequately distinguished from a relation of the same representations that would have only subjective validity -- as when they are connected according to laws of association. In the latter case, all that I could say would be, 'If I support a body, I feel an impression of weight'; I could not say, 'It, the body, is heavy'. Thus to say 'The body is heavy' is not merely to state that the two representations have always been conjoined in my perception, however often that perception be repeated; what we are asserting is that they are combined in the object, no matter what the state of the subject may be. P 160 $20 All Sensible Intuitions are subject to the Categories, as Con- ditions under which alone their Manifold can come to- gether in one Consciousness The manifold given in a sensible intuition is necessarily subject to the original synthetic unity of apperception, be- cause in no other way is the unity of intuition possible ($17). But that act of understanding by which the manifold of given representations (be they intuitions or concepts) is brought under one apperception, is the logical function of judgment (cf. $19). All the manifold, therefore, so far as it is given in a single empirical intuition, is determined in respect of one of the logical functions of judgment, and is thereby brought into one consciousness. Now the categories are just these functions of judgment, in so far as they are employed in determination of the manifold of a given intuition (cf. $13). Consequently, the manifold in a given intuition is necessarily subject to the categories. $21 Observation A manifold, contained in an intuition which I call mine, is represented, by means of the synthesis of the understanding, as belonging to the necessary unity of self-consciousness; and this is effected by means of the category. This [requirement of a] category therefore shows that the empirical consciousness of a given manifold in a single intuition is subject to a pure self- consciousness a priori, just as is empirical intuition to a pure sensible intuition, which likewise takes place a priori. Thus in the above proposition a beginning is made of a deduction of the pure concepts of understanding; The proof of this rests on the represented unity of intuition, by which an object is given. This unity of intuition always includes in itself a synthesis of the manifold given for an intuition, and so already contains the relation of this manifold to the unity of apper- ception. P 160 and in this deduction, since the categories have their source in the understanding alone, independently of sensibility, I must abstract from the P 161 mode in which the manifold for an empirical intuition is given, and must direct attention solely to the unity which, in terms of the category, and by means of the understanding, enters into the intuition. In what follows (cf. $26) it will be shown, from the mode in which the empirical intuition is given in sensibil- ity, that its unity is no other than that which the category (according to $20) prescribes to the manifold of a given in- tuition in general. Only thus, by demonstration of the a priori validity of the categories in respect of all objects of our senses, will the purpose of the deduction be fully attained. But in the above proof there is one feature from which I could not abstract, the feature, namely, that the manifold to be intuited must be given prior to the synthesis of understanding, and independently of it. How this takes place, remains here undetermined. For were I to think an understanding which is itself intuitive (as, for example, a divine understanding which should not represent to itself given objects, but through whose representation the objects should themselves be given or pro- duced), the categories would have no meaning whatsoever in respect of such a mode of knowledge. They are merely rules for an understanding whose whole power consists in thought, con- sists, that is, in the act whereby it brings the synthesis of a mani- fold, given to it from elsewhere in intuition, to the unity of ap- perception -- a faculty, therefore, which by itself knows nothing whatsoever, but merely combines and arranges the material of knowledge, that is, the intuition, which must be given to it by the object. This peculiarity of our understanding, that it can produce a priori unity of apperception solely by means of the categories, and only by such and so many, is as little capable of further explanation as why we have just these and no other functions of judgment, or why space and time are the only forms of our possible intuition. $22 The Category has no other Application in Knowledge than to Objects of Experience To think an object and to know an object are thus by no means the same thing. Knowledge involves two factors: first, P 162 the concept, through which an object in general is thought (the category); and secondly, the intuition, through which it is given. For if no intuition could be given corresponding to the concept, the concept would still indeed be a thought, so far as its form is concerned, but would be without any object, and no knowledge of anything would be possible by means of it. So far as I could know, there would be nothing, and could be nothing, to which my thought could be applied. Now, as the Aesthetic has shown, the only intuition possible to us is sens- ible; consequently, the thought of an object in general, by means of a pure concept of understanding, can become know- ledge for us only in so far as the concept is related to objects of the senses. Sensible intuition is either pure intuition (space and time) or empirical intuition of that which is immediately represented, through sensation, as actual in space and time. Through the determination of pure intuition we can acquire a priori knowledge of objects, as in mathematics, but only in regard to their form, as appearances; whether there can be things which must be intuited in this form, is still left unde- cided. Mathematical concepts are not, therefore, by themselves knowledge, except on the supposition that there are things which allow of being presented to us only in accordance with the form of that pure sensible intuition. Now things in space and time are given only in so far as they are perceptions (that is, representations accompanied by sensation) -- therefore only through empirical representation. Consequently, the pure concepts of understanding, even when they are applied to a - priori intuitions, as in mathematics, yield knowledge only in so far as these intuitions -- and therefore indirectly by their means the pure concepts also -- can be applied to empirical in- tuitions. Even, therefore, with the aid of [pure] intuition, the categories do not afford us any knowledge of things; they do so only through their possible application to empirical intui- tion. In other words, they serve only for the possibility of em- pirical knowledge; and such knowledge is what we entitle experience. Our conclusion is therefore this: the categories, as yielding knowledge of things, have no kind of application, save only in regard to things which may be objects of possible experience. P 163 $23 The above proposition is of the greatest importance; for it determines the limits of the employment of the pure concepts of understanding in regard to objects, just as the Transcen- dental Aesthetic determined the limits of the employment of the pure form of our sensible intuition. Space and time, as con- ditions under which alone objects can possibly be given to us, are valid no further than for objects of the senses, and there- fore only for experience. Beyond these limits they represent nothing; for they are only in the senses, and beyond them have no reality. The pure concepts of understanding are free from this limitation, and extend to objects of intuition in general, be the intuition like or unlike ours, if only it be sensible and not intellectual. But this extension of concepts beyond our sensible intuition is of no advantage to us. For as concepts of objects they are then empty, and do not even enable us to judge of their objects whether or not they are possible. They are mere forms of thought, without objective reality, since we have no intuition at hand to which the synthetic unity of apperception, which constitutes the whole content of these forms, could be applied, and in being so applied determine an object. Only our sensible and empirical intuition can give to them body and meaning. If we suppose an object of a non-sensible intuition to be given, we can indeed represent it through all the predicates which are implied in the presupposition that it has none of the characteristics proper to sensible intuition; that it is not ex- tended or in space, that its duration is not a time, that no change (succession of determinations in time) is to be met with in it, etc. But there is no proper knowledge if I thus merely in- dicate what the intuition of an object is not, without being able to say what it is that is contained in the intuition. For I have not then shown that the object which I am thinking through my pure concept is even so much as possible, not being in a position to give any intuition corresponding to the concept, and being able only to say that our intuition is not applicable to it. But what has chiefly to be noted is this, that to such a some- thing [in general] not a single one of all the categories could P 164 be applied. We could not, for instance, apply to it the concept of substance, meaning something which can exist as subject and never as mere predicate. For save in so far as empirical intuition provides the instance to which to apply it, I do not know whether there can be anything that corresponds to such a form of thought. But of this more hereafter. $24 The Application of the Categories to Objects of the Senses in General The pure concepts of understanding relate, through the mere understanding, to objects of intuition in general, whether that intuition be our own or any other, provided only it be sensible. The concepts are, however, for this very reason, mere forms of thought, through which alone no determinate object is known. The synthesis or combination of the manifold in them relates only to the unity of apperception, and is thereby the ground of the possibility of a priori knowledge, so far as such knowledge rests on the understanding. This synthesis, there- fore, is at once transcendental and also purely intellectual. But since there lies in us a certain form of a priori sensible intui- tion, which depends on the receptivity of the faculty of repre- sentation (sensibility), the understanding, as spontaneity, is able to determine inner sense through the manifold of given repre- sentations, in accordance with the synthetic unity of apper- ception, and so to think synthetic unity of the apperception of the manifold of a priori sensible intuition -- that being the condition under which all objects of our human intuition must necessarily stand. In this way the categories, in themselves mere forms of thought, obtain objective reality, that is, ap- plication to objects which can be given us in intuition. These objects, however, are only appearances, for it is solely of appearances that we can have a priori intuition. This synthesis of the manifold of sensible intuition, which is possible and necessary a priori, may be entitled figurative synthesis (synthesis speciosa), to distinguish it from the syn- thesis which is thought in the mere category in respect of the manifold of an intuition in general, and which is entitled combination through the understanding (synthesis intellectua- P 165 lis). Both are transcendental, not merely as taking place a priori, but also as conditioning the possibility of other a priori knowledge. But the figurative synthesis, if it be directed merely to the original synthetic unity of apperception, that is, to the transcendental unity which is thought in the categories, must, in order to be distinguished from the merely intellec- tual combination, be called the transcendental synthesis of imagination. Imagination is the faculty of representing in intuition an object that is not itself present. Now since all our intuition is sensible, the imagination, owing to the subjective condition under which alone it can give to the concepts of understanding a corresponding intuition, belongs to sen- sibility. But inasmuch as its synthesis is an expression of spontaneity, which is determinative and not, like sense, deter- minable merely, and which is therefore able to determine sense a priori in respect of its form in accordance with the unity of apperception, imagination is to that extent a faculty which determines the sensibility a priori; and its synthesis of intuitions, conforming as it does to the categories, must be the transcendental synthesis of imagination. This synthesis is an action of the understanding on the sensibility; and is its first application -- and thereby the ground of all its other applications -- to the objects of our possible intuition. As figurative, it is distinguished from the intellectual synthesis, which is carried out by the understanding alone, without the aid of the imagination. In so far as imagination is spontaneity, I sometimes also entitle it the productive imagination, to dis- tinguish it from the reproductive imagination, whose synthesis is entirely subject to empirical laws, the laws, namely, of association, and which therefore contributes nothing to the explanation of the possibility of a priori knowledge. The repro- ductive synthesis falls within the domain, not of transcendental philosophy, but of psychology. * * * This is a suitable place for explaining the paradox which must have been obvious to everyone in our exposition of the P 166 form of inner sense ($6): namely, that this sense represents to consciousness even our own selves only as we appear to ourselves, not as we are in ourselves. For we intuit ourselves only as we are inwardly affected, and this would seem to be contradictory, since we should then have to be in a passive relation [of active affection] to ourselves. It is to avoid this contradiction that in systems of psychology inner sense, which we have carefully distinguished from the faculty of apperception, is commonly regarded as being identical with it. What determines inner sense is the understanding and its original power of combining the manifold of intuition, that is, of bringing it under an apperception, upon which the possi- bility of understanding itself rest. Now the understanding in us men is not a faculty of intuitions, and cannot, even if intuitions be given in sensibility, take them up into itself in such manner as to combine them as the manifold of its own intuition. Its synthesis, therefore, if the synthesis be viewed by itself alone, is nothing but the unity of the act, of which, as an act, it is conscious to itself, even without [the aid of] sensibility, but through which it is yet able to determine the sensibility. The understanding, that is to say, in respect of the manifold which may be given to it in accord- ance with the form of sensible intuition, is able to deter- mine sensibility inwardly. Thus the understanding, under the title of a transcendental synthesis of imagination, performs this act upon the passive subject, whose faculty it is, and we are therefore justified in saying that inner sense is affected thereby. Apperception and its synthetic unity is, indeed, very far from being identical with inner sense. The former, as the source of all combination, applies to the manifold of intui- tions in general, and in the guise of the categories, prior to all sensible intuition, to objects in general. Inner sense, on the other hand, contains the mere form of intuition, but without combination of the manifold in it, and therefore so far contains no determinate intuition, which is possible only through the consciousness of the determination of the manifold by the transcendental act of imagination (synthetic influence P 167 of the understanding upon inner sense), which I have entitled figurative synthesis. This we can always perceive in ourselves. We cannot think a line without drawing it in thought, or a circle without describing it. We cannot represent the three dimensions of space save by setting three lines at right angles to one another from the same point. Even time itself we cannot represent, save in so far as we attend, in the drawing of a straight line (which has to serve as the outer figurative representation of time), merely to the act of the synthesis of the manifold where- by we successively determine inner sense, and in so doing attend to the succession of this determination in inner sense. Motion, as an act of the subject (not as a determination of an object), and therefore the synthesis of the manifold in space, first produces the concept of succession -- if we abstract from this manifold and attend solely to the act through which we determine the inner sense according to its form. The understanding does not, therefore, find in inner sense such a combination of the manifold, but produces it, in that it affects that sense. How the 'I' that thinks can be distinct from the 'I' that intuits itself (for I can represent still other modes of intuition as at least possible), and yet, as being the same subject, can be identical with the latter; and how, therefore, I can say: "I, as intelligence and thinking subject, know myself as an object that is thought, in so far as I am given to myself [as some- thing other or] beyond that [I] which is [given to myself] in intuition, and yet know myself, like other phenomena, only as I appear to myself, not as I am to the understanding" -- these are questions that raise no greater nor less difficulty than how I can be an object to myself at all, and, more particularly, an object of intuition and of inner perceptions. Motion of an object in space does not belong to a pure science, and consequently not to geometry. For the fact that something is movable cannot be known a priori, but only through experience. Motion, however, considered as the describing of a space, is a pure act of the successive synthesis of the manifold in outer intuition in general by means of the productive imagination, and belongs not only to geometry, but even to transcendental philosophy. P 168 Indeed, that this is how it must be, is easily shown -- if we admit that space is merely a pure form of the appearances of outer sense -- by the fact that we cannot obtain for ourselves a representation of time, which is not an object of outer in- tuition, except under the image of a line, which we draw, and that by this mode of depicting it alone could we know the singleness of its dimension; and similarly by the fact that for all inner perceptions we must derive the determination of lengths of time or of points of time from the changes which are exhibited to us in outer things, and that the determina- tions of inner sense have therefore to be arranged as appear- ances in time in precisely the same manner in which we arrange those of outer sense in space. If, then, as regards the latter, we admit that we know objects only in so far as we are externally affected, we must also recognise, as regards inner sense, that by means of it we intuit ourselves only as we are inwardly affected by ourselves; in other words, that, so far as inner intuition is concerned, we know our own subject only as appearance, not as it is in itself. $25 On the other hand, in the transcendental synthesis of the manifold of representations in general, and therefore in the synthetic original unity of apperception, I am conscious of myself, not as I appear to myself, nor as I am in myself, but only that I am. This representation is a thought, not an intui- tion. Now in order to know ourselves, there is required in addition to the act of thought, which brings the manifold of every possible intuition to the unity of apperception, a de- terminate mode of intuition, whereby this manifold is given; ++ I do not see why so much difficulty should be found in admit- ting that our inner sense is affected by ourselves. Such affection finds exemplification in each and every act of attention. In every act of attention the understanding determines inner sense, in accordance with the combination which it thinks, to that inner intuition which corresponds to the manifold in the synthesis of the understanding. How much the mind is usually thereby affected, everyone will be able to perceive in himself. P 168 it therefore follows that although my existence is not indeed P 169 appearance (still less mere illusion), the determination of my existence can take place only in conformity with the form of inner sense, according to the special mode in which the mani- fold, which I combine, is given in inner intuition. Accordingly I have no knowledge of myself as I am but merely as I appear to myself. The consciousness of self is thus very far from being a knowledge of the self, notwithstanding all the categories which [are being employed to] constitute the thought of an object in general, through combination of the manifold in one apperception. Just as for knowledge of an object distinct from me I require, besides the thought of an object in general (in the category), an intuition by which I determine that general concept, so for knowledge of myself I require, besides the consciousness, that is, besides the thought of myself, an intuition of the manifold in me, by which I determine this thought. I exist as an intelligence which is conscious solely of its power of combination; but in respect of the manifold which it has to combine I am subjected to a limiting condition (entitled inner sense), namely, that this combination can be made intuitable only according to relations of time, which lie entirely outside the concepts of understanding, strictly re- garded. Such an intelligence, therefore, can know itself only as it appears to itself in respect of an intuition which is not intellectual and cannot be given by the understanding itself, not as it would know itself if its intuition were intellectual. ++ The 'I think' expresses the act of determining my existence. Existence is already given thereby, but the mode in which I am to determine this existence, that is, the manifold belonging to it, is not thereby given. In order that it be given, self-intuition is required; and such intuition is conditioned by a given a priori form, namely, time, which is sensible and belongs to the receptivity of the deter- minable [in me]. Now since I do not have another self-intuition which gives the determining in me (I am conscious only of the spontaneity of it) prior to the act of determination, as time does in the case of the determinable, I cannot determine my existence as that of a self-active being; all that I can do is to represent to myself the spontaneity of my thought, that is, of the determination; and my existence is still only determinable sensibly, that is, as the existence of an appearance. But it is owing to this spontaneity that I entitle myself an intelligence. P 170 $26 Transcendental Deduction of the Universally Possible Em- ployment in experience of the Pure Concepts of the Understanding In the metaphysical deduction the a priori origin of the categories has been proved through their complete agreement with the general logical functions of thought; in the transcen- dental deduction we have shown their possibility as a priori modes of knowledge of objects of an intuition in general (cf. $$20, 21). We have now to explain the possibility of knowing a priori, by means of categories, whatever objects may present themselves to our senses, not indeed in respect of the form of their intuition, but in respect of the laws of their combination, and so, as it were, of prescribing laws to nature, and even of making nature possible. For unless the cate- gories discharged this function, there could be no explaining why everything that can be presented to our senses must be subject to laws which have their origin a priori in the under- standing alone. First of all, I may draw attention to the fact that by syn- thesis of apprehension I understand that combination of the manifold in an empirical intuition, whereby perception, that is, empirical consciousness of the intuition (as appearance), is possible. In the representations of space and time we have a priori forms of outer and inner sensible intuition; and to these the synthesis of apprehension of the manifold of appearance must always conform, because in no other way can the synthesis take place at all. But space and time are represented a priori not merely as forms of sensible intuition, but as themselves intuitions which contain a manifold [of their own], and there- fore are represented with the determination of the unity of this manifold (vide the Transcendental Aesthetic). Thus P 171 unity of the synthesis of the manifold, without or within us, and consequently also a combination to which everything that is to be represented as determined in space or in time must conform, is given a priori as the condition of the synthesis of all apprehension -- not indeed in, but with these intuitions. This synthetic unity can be no other than the unity of the combination of the manifold of a given intuition in general in an original consciousness, in accordance with the cate- gories, in so far as the combination is applied to our sensible intuition. All synthesis, therefore, even that which renders perception possible, is subject to the categories; and since experience is knowledge by means of connected perceptions, the categories are conditions of the possibility of experience, and are therefore valid a priori for all objects of experience. * * * When, for instance, by apprehension of the manifold of a house I make the empirical intuition of it into a perception, the necessary unity of space and of outer sensible intuition in general lies at the basis of my apprehension, and I draw as it were the outline of the house in conformity with this synthetic unity of the manifold in space. But if I abstract from the form of space, this same synthetic unity has its seat in the under- standing, and is the category of the synthesis of the homogene- ous in an intuition in general, that is, the category of quantity. To this category, therefore, the synthesis of apprehension, that is to say, the perception, must completely conform. P 170n ++ Space, represented as object (as we are required to do in geo- metry), contains more than mere form of intuition; it also contains combination of the manifold, given according to the form of sensi- bility, in an intuitive representation, so that the form of intuition gives only a manifold, the formal intuition gives unity of representa- tion. In the Aesthetic I have treated this unity as belonging merely P 171n to sensibility, simply in order to emphasise that it precedes any con- cept, although, as a matter of fact, it presupposes a synthesis which does not belong to the senses but through which all concepts of space and time first become possible. For since by its means (in that the understanding determines the sensibility) space and time are first given as intuitions, the unity of this a priori intuition belongs to space and time, and not to the concept of the understanding (cf. $24). ++ In this manner it is proved that the synthesis of apprehension, which is empirical, must necessarily be in conformity with the syn- thesis of apperception, which is intellectual and is contained in the category completely a priori. It is one and the same spontaneity, P 172n which in the one case, under the title of imagination, and in the other case, under the title of understanding, brings combination into the manifold of intuition. P 172 When, to take another example, I perceive the freezing of water, I apprehend two states, fluidity and solidity, and these as standing to one another in a relation of time. But in time, which I place at the basis of the appearance [in so far] as [it is] inner intuition, I necessarily represent to myself synthetic unity of the manifold, without which that relation of time could not be given in an intuition as being determined in respect of time-sequence. Now this synthetic unity, as a condition a priori under which I combine the manifold of an intui- tion in general, is -- if I abstract from the constant form of my inner intuition, namely, time -- the category of cause, by means of which, when I apply it to my sensibility, I deter- mine everything that happens in accordance with the relation which it prescribes, and I do so in time in general. Thus my apprehension of such an event, and therefore the event itself, considered as a possible perception, is subject to the con- cept of the relation of effects and causes, and so in all other cases. Categories are concepts which prescribe laws a priori to appearances, and therefore to nature, the sum of all appear- ances (natura materialiter spectata). The question therefore arises, how it can be conceivable that nature should have to proceed in accordance with categories which yet are not de- rived from it, and do not model themselves upon its pattern; that is, how they can determine a priori the combination of the manifold of nature, while yet they are not derived from it. The solution of this seeming enigma is as follows. That the laws of appearances in nature must agree with the understanding and its a priori form, that is, with its faculty of combining the manifold in general, is no more surprising than that the appearances themselves must agree with the form of a priori sensible intuition. For just as appearances do not exist in themselves but only relatively to the subject in which, so far as it has senses, they inhere, so the laws do not exist in the appearances but only relatively to this same being, so far as it has understanding. Things in themselves would necessarily, P 173 apart from any understanding that knows them, conform to laws of their own. But appearances are only representations of things which are unknown as regards what they may be in themselves. As mere representations, they are subject to no law of connection save that which the connecting faculty pre- scribes. Now it is imagination that connects the manifold of sensible intuition; and imagination is dependent for the unity of its intellectual synthesis upon the understanding, and for the manifoldness of its apprehension upon sensibility. All possible perception is thus dependent upon synthesis of appre- hension, and this empirical synthesis in turn upon transcen- dental synthesis, and therefore upon the categories. Conse- quently, all possible perceptions, and therefore everything that can come to empirical consciousness, that is, all appearances of nature, must, so far as their connection is concerned, be sub- ject to the categories. Nature, considered merely as nature in general, is dependent upon these categories as the original ground of its necessary conformity to law (natura formaliter spectata). Pure understanding is not, however, in a position, through mere categories, to prescribe to appearances any a priori laws other than those which are involved in a nature in general, that is, in the conformity to law of all appearances in space and time. Special laws, as concerning those appear- ances which are empirically determined, cannot in their specific character be derived from the categories, although they are one and all subject to them. To obtain any knowledge what- soever of these special laws, we must resort to experience; but it is the a priori laws that alone can instruct us in regard to experience in general, and as to what it is that can be known as an object of experience. $27 Outcome of this Deduction of the Concepts of Understanding We cannot think an object save through categories; we cannot know an object so thought save through intuitions corresponding to these concepts. Now all our intuitions are sensible; and this knowledge, in so far as its object is given, is empirical. But empirical knowledge is experience. Conse- P 174 quently, there can be no a priori knowledge, except of objects of possible experience. But although this knowledge is limited to objects of ex- perience, it is not therefore all derived from experience. The pure intuitions [of receptivity] and the pure concepts of under- standing are elements in knowledge, and both are found in us a priori. There are only two ways in which we can account for a necessary agreement of experience with the concepts of its objects: either experience makes these concepts possible or these concepts make experience possible. The former supposition does not hold in respect of the categories (nor of pure sensible intuition); for since they are a priori concepts, and there- fore independent of experience, the ascription to them of an empirical origin would be a sort of generatio aequivoca. There remains, therefore, only the second supposition -- a system, as it were, of the epigenesis of pure reason -- namely, that the cate- gories contain, on the side of the understanding, the grounds of the possibility of all experience in general. How they make experience possible, and what are the principles of the possi- bility of experience that they supply in their application to appearances, will be shown more fully in the following chapter on the transcendental employment of the faculty of judgment. A middle course may be proposed between the two above mentioned, namely, that the categories are neither self-thought first principles a priori of our knowledge nor derived from ex- perience, but subjective dispositions of thought, implanted in us from the first moment of our existence, and so ordered by our Creator that their employment is in complete harmony with the laws of nature in accordance with which experience P 175 proceeds -- a kind of preformation-system of pure reason. P 174n ++ Lest my readers should stumble at the alarming evil con- sequences which may over-hastily be inferred from this statement, I may remind them that for thought the categories are not limited by the conditions of our sensible intuition, but have an unlimited field. It is only the knowledge of that which we think, the determining of the object, that requires intuition. In the absence of intuition, the thought of the object may still have its true and useful consequences, as regards the subject's employment of reason. The use of reason is not always directed to the determination of an object, that is, to know- ledge, but also to the determination of the subject and of its volition -- a use which cannot be here dealt with. P 175 Apart, however, from the objection that on such an hypo- thesis we can set no limit to the assumption of predetermined dispositions to future judgments, there is this decisive objec- tion against the suggested middle course, that the necessity of the categories, which belongs to their very conception, would then have to be sacrificed. The concept of cause, for instance, which expresses the necessity of an event under a presupposed condition, would be false if it rested only on an arbitrary subjective necessity, implanted in us, of connecting certain empirical representations according to the rule of causal relation. I would not then be able to say that the effect is connected with the cause in the object, that is to say, neces- sarily, but only that I am so constituted that I cannot think this representation otherwise than as thus connected. This is exactly what the sceptic most desires. For if this be the situa- tion, all our insight, resting on the supposed objective validity of our judgments, is nothing but sheer illusion; nor would there be wanting people who would refuse to admit this sub- jective necessity, a necessity which can only be felt. Certainly a man cannot dispute with anyone regarding that which de- pends merely on the mode in which he is himself organised. Brief Outline of this Deduction The deduction is the exposition of the pure concepts of the understanding, and therewith of all theoretical a priori know- ledge, as principles of the possibility of experience -- the prin- ciples being here taken as the determination of appearances in space and time in general, and this determination, in turn, as ultimately following from the original synthetic unity of apper- ception, as the form of the understanding in its relation to space and time, the original forms of sensibility. I consider the division by numbered paragraphs as neces- sary up to this point, because thus far we have had to treat of the elementary concepts. We have now to give an account of their employment, and the exposition may therefore pro- ceed in continuous fashion, without such numbering.