Critique of Pure Reason

by Immanuel Kant

  3. The following are all the relations of thought in judgments:—

  a. Relation of the predicate to the subject.

  b. Relation of the cause to its effect.

  c. Relation of subdivided knowledge, and of the collected members of the subdivision to each other.

  In the first class of judgments we consider two concepts, in the second two judgments, in the third several judgments in their relation to each other. The hypothetical proposition, if perfect justice exists, the obstinately wicked is punished, contains really the relation of two propositions, namely, there is a perfect justice, and the obstinately wicked is punished. Whether both these propositions are true remains unsettled. It is only the consequence which is laid down by this judgment.

  The disjunctive judgment contains the relation of two or more propositions to each other, but not as a consequence, but in the form of a logical opposition, the sphere of the one excluding the sphere of the other, and at the same time in the form of community, all the propositions together filling the whole sphere of the intended knowledge. The disjunctive judgment contains therefore a relation of the parts of the whole sphere of a given knowledge, in which the sphere of each part forms the complement of the sphere of the other, all being contained within the whole sphere of the subdivided knowledge. We may say, for instance, the world exists either by blind chance, or by internal necessity, or by an external cause. Each of these sentences occupies a part of the sphere of all possible knowledge with regard to the existence of the world, while all together occupy the whole sphere. To take away the knowledge from one of these spheres is the same as to place it into one of the other spheres, and to place it in one sphere is the same as to take it away from the others. There exists therefore in disjunctive judgments a certain community of the different divisions of knowledge, so that they mutually exclude each other, and yet thereby determine in their totality the true knowledge, because, if taken together, they constitute the whole contents of one given knowledge. This is all I have to observe here for the sake of what is to follow hereafter.

  4. The modality of judgments is a very peculiar function, for it contributes nothing to the contents of a judgment (because, besides quantity, quality, and relation, there is nothing else that could constitute the contents of a judgment), but refers only to the nature of the copula in relation to thought in general. Problematical judgments are those in which affirmation or negation are taken as possible (optional) only, while in assertory judgments affirmation or negation is taken as real (true), in apodictic as necessary.2 Thus the two judgments, the relation of which constitutes the hypothetical judgment (antecedens et consequens) and likewise the judgments the reciprocal relation of which forms the disjunctive judgment (members of subdivision), are always problematical only. In the example given above, the proposition, there exists a perfect justice, is not made as an assertory, but only as an optional judgment, which may be accepted or not, the consequence only being assertory. It is clear therefore that some of these judgments may be wrong, and may yet, if taken problematically, contain the conditions of the knowledge of truth. Thus, in our disjunctive judgment, one of its component judgments, namely, the world exists by blind chance, has a problematical meaning only, on the supposition that some one might for one moment take such a view, but serves, at the same time, like the indication of a false road among all the roads that might be taken, to find out the true one.

  The problematical proposition is therefore that which expresses logical (not objective) possibility only, that is, a free choice of admitting such a proposition, and a purely optional admission of it into the understanding. The assertory proposition implies logical reality or truth. Thus, for instance, in a hypothetical syllogism the antecedens in the major is problematical, in the minor assertory, showing that the proposition conforms to the understanding according to its laws. The apodictic proposition represents the assertory as determined by these very laws of the understanding, and therefore as asserting a priori, and thus expresses logical necessity. As in this way everything is arranged step by step in the understanding, inasmuch as we begin with judging problematically, then proceed to an assertory acceptation, and finally maintain our proposition as inseparably united with the understanding, that is as necessary and apodictic, we may be allowed to call these three functions of modality so many varieties or moment of thought.

  Method Of The Discovery Of All Pure Concepts Of The Understanding

  Section III

  Of the Pure Concepts of the Understanding, or of the Categories

  General logic, as we have often said, takes no account of the contents of our knowledge, but expects that representations will come from elsewhere in order to be turned into concepts by an analytical process. Transcendental logic, on the contrary, has before it the manifold contents of sensibility a priori, supplied by transcendental æsthetic as the material for the concepts of the pure understanding, without which those concepts would be without any contents, therefore entirely empty. It is true that space and time contain what is manifold in the pure intuition a priori, but they belong also to the conditions of the receptivity of our mind under which alone it can receive representations of objects, and which therefore must affect the concepts of them also. The spontaneity of our thought requires that what is manifold in the pure intuition should first be in a certain way examined, received, and connected, in order to produce a knowledge of it. This act I call synthesis.

  In its most general sense, I understand by synthesis the act of arranging different representations together, and of comprehending what is manifold in them under one form of knowledge. Such a synthesis is pure, if the manifold is not given empirically, but a priori (as in time and space). Before we can proceed to an analysis of our representations, these must first be given, and, as far as their contents are concerned, no concepts can arise analytically. Knowledge is first produced by the synthesis of what is manifold (whether given empirically or a priori). That knowledge may at first be crude and confused and in need of analysis, but it is synthesis which really collects the elements of knowledge, and unites them to a certain extent. It is therefore the first thing which we have to consider, if we want to form an opinion on the first origin of our knowledge.

  We shall see hereafter that synthesis in general is the mere result of what I call the faculty of imagination, a blind but indispensable function of the soul, without which we should have no knowledge whatsoever, but of the existence of which we are scarcely conscious. But to reduce this synthesis to concepts is a function that belongs to the understanding, and by which the understanding supplies us for the first time with knowledge properly so called.

  Pure synthesis in its most general meaning gives us the pure concept of the understanding. By this pure synthesis I mean that which rests on the foundation of what I call synthetical unity a priori. Thus our counting (as we best perceive when dealing with higher numbers) is a synthesis according to concepts, because resting on a common ground of unity, as for instance, the decade. The unity of the synthesis of the manifold becomes necessary under this concept.

  By means of analysis different representations are brought under one concept, a task treated of in general logic; but how to bring, not the representations, but the pure synthesis of representations, under concepts, that is what transcendental logic means to teach. The first that must be given us a priori for the sake of knowledge of all objects, is the manifold in pure intuition. The second is, the synthesis of the manifold by means of imagination. But this does not yet produce true knowledge. The concepts which impart unity to this pure synthesis and consist entirely in the representation of this necessary synthetical unity, add the third contribution towards the knowledge of an object, and rest on the understanding.

  The same function which imparts unity to various representations in one judgment imparts unity likewise to the mere synthesis of various representations in one intuition, which in a general way may be called the pure concept of the understanding. The same underst
anding, and by the same operations by which in concepts it achieves through analytical unity the logical form of a judgment, introduces also, through the synthetical unity of the manifold in intuition, a transcendental element into its representations. They are therefore called pure concepts of the understanding, and they refer a priori to objects, which would be quite impossible in general logic.

  In this manner there arise exactly so many pure concepts of the understanding which refer a priori to objects of intuition in general, as there were in our table logical functions in all possible judgments, because those functions completely exhaust the understanding, and comprehend every one of its faculties. Borrowing a term of Aristotle, we shall call these concepts categories, our intention being originally the same as his, though widely diverging from it in its practical application.

  TABLE OF CATEGORIES

  I

  Of Quantity

  Unity.

  Plurality.

  Totality.

  II

  III

  Of Quality

  Of Relation

  Reality.

  Of Inherence and Subsistence

  (substantia et accidens).

  Negation.

  Of Causality and Dependence

  (cause and effect).

  Limitation.

  Of Community

  (reciprocity between the active and the

  passive).

  IV

  Of Modality

  Possibility. Impossibility.

  Existence. Non-existence.

  Necessity. Contingency.

  This then is a list of all original pure concepts of synthesis, which belong to the understanding a priori, and for which alone it is called pure understanding; for it is by them alone that it can understand something in the manifold of intuition, that is, think an object in it. The classification is systematical, and founded on a common principle, namely, the faculty of judging (which is the same as the faculty of thinking). It is not the result of a search after pure concepts undertaken at haphazard, the completeness of which, as based on induction only, could never be guaranteed. Nor could we otherwise understand why these concepts only, and no others, abide in the pure understanding. It was an enterprise worthy of an acute thinker like Aristotle to try to discover these fundamental concepts; but as he had no guiding principle he merely picked them up as they occurred to him, and at first gathered up ten of them, which he called categories or predicaments. Afterwards he thought he had discovered five more of them, which he added under the name of post-predicaments. But his table remained imperfect for all that, not to mention that we find in it some modes of pure sensibility (quando, ubi, situs, also prius, simul), also an empirical concept (motus), none of which can belong to this genealogical register of the understanding. Besides, there are some derivative concepts, counted among the fundamental concepts (actio, passio), while some of the latter are entirely wanting.

  With regard to these, it should be remarked that the categories, as the true fundamental 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 mention of the fact may suffice.

  I should like to be allowed to call these pure but derivative concepts of the understanding the predicabilia, in opposition to the predicamenta of the pure understanding. If we are once in possession of the fundamental and primitive concepts, it is easy to add the derivative and secondary, and thus to give a complete image of the genealogical tree of the pure understanding. As at present I am concerned not with the completeness, but only with the principles of a system, I leave this supplementary work for a future occasion. In order to carry it out, one need only consult any of the ontological manuals, and place, for instance, under the category of causality the predicabilia of force, of action, and of passion; under the category of community the predicabilia of presence and resistance; under the predicaments of modality the predicabilia of origin, extinction, change, etc. If we associate the categories among themselves or with the modes of pure sensibility, they yield us a large number of derivative concepts a priori, which it would be useful and interesting to mark and, if possible, to bring to a certain completeness, though this is not essential for our present purpose.

  I intentionally omit here the definitions of these categories, though I may be in possession of them.3 In the sequel I shall dissect these concepts so far as is sufficient for the purpose of the method which I am preparing. In a complete system of pure reason they might be justly demanded, but at present they would only make us lose sight of the principal object of our investigation, by rousing doubts and objections which, without injury to our essential object, may well be relegated to another time. The little I have said ought to be sufficient to show clearly that a complete dictionary of these concepts with all requisite explanations is not only possible, but easy. The compartments exist; they have only to be filled, and with a systematic topic like the present the proper place to which each concept belongs cannot easily be missed, nor compartments be passed over which are still empty.4

  1 Veränderlich in the First Edition is rightly corrected into theilbar in later editions, though in the Second it is still veränderlich.

  2 As if in the first, thought were a function of the understanding, in the second, of the faculty of judgment, in the third, of reason; a remark which will receive its elucidation in the sequel.

  3 See, however, Karl's remarks on (First Edition).

  4 Here follows in the Second Edition, Supplement XII.

  | Go to Table of Contents |

  Transcendental Analytic

  Chapter II

  Of the Deduction of the Pure Concepts of the Understanding

  Section I

  Of the Principles of a Transcendental Deduction in General

  JURISTS, when speaking of rights and claims, distinguish in every lawsuit the question of right (quid juris) from the question of fact (quid facti), and in demanding proof of both they call the former, which is to show the right or, it may be, the claim, the deduction. We, not being jurists, make use of a number of empirical concepts, without opposition from anybody, and consider ourselves justified, without any deduction, in attaching to them a sense or imaginary meaning, because we can always appeal to experience to prove their objective reality. There exist however illegitimate concepts also, such as, for instance, chance, or fate, which through an almost general indulgence are allowed to be current, but are yet from time to time challenged by the question quid juris. In that case we are greatly embarrassed in looking for their deduction, there being no clear legal title, whether from experience or from reason, on which their claim to employment could be clearly established.

  Among the many concepts, however, which enter into the complicated code of human knowledge, there are some which are destined for pure use a priori, independent of all experience, and such a claim requires at all times a deduction,1 because proofs from experience would not be sufficient to establish the legitimacy of such a use, though it is necessary to know how much concepts can refer to objects which they do not find in experience. I call the explanation of the manner how such concepts can a priori refer to objects their transcendental deduction, and distinguish it from the empirical deduction which shows the manner how a concept may be gained by experience and by reflection on experience; this does not touch the legitimacy, but only the fact whence the possession of the concept arose.

  We have already become acquainted with two totally distinct classes of concepts, which nevertheless agree in this, that they both refer a priori to objects, namely, the concepts of space and time as forms of sensibility, and the categories as concepts of the understanding. It would be labour lost to attempt an empirical deduction of them, because their distinguishing characteristic is that they refer to objects without having borrowed anything from experience for their representation. If therefore a deduction of them is necessary, it can only be transcendental.


  It is possible, however, with regard to these concepts, as with regard to all knowledge, to try to discover in experience, if not the principle of their possibility, yet the contingent causes of their production. And here we see that the impressions of the senses give the first impulse to the whole faculty of knowledge with respect to them, and thus produce experience which consists of two very heterogeneous elements, namely, matter for knowledge, derived from the senses, and a certain form according to which it is arranged, derived from the internal source of pure intuition and pure thought, first brought into action by the former, and then producing concepts. Such an investigation of the first efforts of our faculty of knowledge, beginning with single perceptions and rising to general concepts, is no doubt very useful, and we have to thank the famous Locke for having been the first to open the way to it. A deduction of the pure concepts a priori, however, is quite impossible in that way. It lies in a different direction, because, with reference to their future use, which is to be entirely independent of experience, a very different certificate of birth will be required from that of mere descent from experience. We may call this attempted physiological derivation (which cannot properly be called deduction, because it refers to a quaestio facti), the explanation of the possession of pure knowledge. It is clear therefore that of these pure concepts a priori a transcendental deduction only is possible, and that to attempt an empirical deduction of them is mere waste of time, which no one would think of except those who have never understood the very peculiar nature of that kind of knowledge.