A Commentary to Kant's 'Critique of Pure Reason'

by Norman Kemp Smith

These considerations bring us to the real source of Kant’s perverse argumentation, namely, the artificial (but none the less imperious) demands of his architectonic. He is constrained to provide a set of principles corresponding to the categories of modality. The definitions of the modal categories have therefore to be called by that inappropriate name. But that is not the end of the matter. In order to meet the needs of his logical framework, Kant proceeds even further than he had ventured to do in the sections on the Axioms of Intuition and Anticipations of Perception. There he fell so far short as to provide only a single principle in each case. In dealing, however, with the categories of relation he has been able to define each of the three categories separately, and to derive from each a separate principle. Many of the defects in his argument are, indeed, traceable to this source. The close interrelations of the three principles are, as we have had occasion to note, seriously obscured. But still, in the main, separate treatment of each has proved feasible. Kant, encouraged, as we may believe, by this successful fulfilment of architectonic requirements, now sets himself to develop, in similar fashion, a separate principle for each modal category. But for any such enterprise the conditions are less favourable than in the case of the categories of relation. For, as just indicated, no one of the three can, on Critical principles, possess any genuine meaning save in its relation to the others. Before following out this line of criticism, we must however note some further points in Kant’s argument.

In A 219 = B 266, and again in A 225 = B 272, Kant makes the statement that a concept can be complete prior to any decision as to its possibility, actuality, or necessity. This contention is capable of being interpreted in two quite independent ways, and in only one of those ways is it tenable. He may mean that the distinction between the possible, the actual, and the necessary, does not concern the objectively real, which as such is always both actual and necessary, but only the subjective attitude of the individual towards the objects of his thought and experience. From the Critical standpoint, as we have been arguing, such a contention is entirely just. But Kant would seem in the above statement to be chiefly concerned to maintain that a conception may be complete and determinate, even while we remain in doubt whether the existence for which it stands is even possible.[1262] Such a view is merely a relic of the Leibnizian rationalism from which he is striving to break away. All existences have their place in a systematic order of experience, and no conception of them can be either complete or determinate which fails to specify the causal context to which they belong. The process of specifying the detail of a concept is the only process whereby we can define its possibility, actuality, or necessity.[1263] Were it capable of complete statement without determination of its modal character, it could never form part of a unified experience. The examples of “fictitious” concepts, which Kant cites, are either so determinate as to be demonstrably inconsistent with experience, and therefore empirically impossible, or so indeterminate as to afford no sufficient means of deciding even as to their possibility.

There is a further objection to the definition given of possibility in the first Postulate. After stating that the possible is what agrees with the formal conditions of experience, Kant proceeds, on the one hand, to argue that the forms of intuition and the categories of understanding may, in accordance with this criterion, be viewed as possible, and, on the other hand, to maintain that no other concepts can be so regarded.[1264] That is to say, the possible, as thus interpreted, does not consist in something additional to, and in harmony with, the conditions of experience, but reduces without remainder to those very forms. Now Kant is not betrayed merely by inadvertence into thus narrowing the sphere of the possible; such limitation is an almost inevitable consequence of the one-sided manner in which he has treated the concept of the possible in this first Postulate. He professes to be proceeding in the light of the results obtained in the transcendental deduction, and to be defining the possible in terms of the conditions which make sense-experience possible. But the deduction has shown that experience is possible only in so far as the material factors co-operate with the formal. And when this is recognised, it becomes obvious that a definition of the possible in terms of sensation,—namely, as that which is capable of being presented in sense-perception,—is equally legitimate, and is indeed required in order to correct the deficiencies of the definition which Kant has himself given. As both factors are indispensable in all possible experience, both must be reckoned with in defining the possible.

Kant’s argument in the fifth paragraph is somewhat obscured by its context. He is contending that fictitious (gedichtete) concepts, elaborated from the contents presented in perception, cannot be determined as possible. As they involve sensuous contents, the formal elements of experience do not suffice for proof of their possibility; and since the contents are supposed to have been recombined in ways not supported by experience, an empirical criterion is equally inapplicable. Obviously Kant is here using the term ‘possible’ not in the meaning of the first Postulate, but in its narrower connotation as signifying that which is capable of objective reality. Such fictitious concepts may completely fulfil all the demands prescribed by space, time, and the categories, and yet, as he here insists, be none the less incapable of objective existence.

The argument is still further obscured by the character of the concrete examples which Kant cites. They involve modes of action or of intuition which contradict the very conditions of human experience, and so for that reason alone fall outside the realm of the empirically possible. That would not, however, seem to be Kant’s meaning in employing them. Assumed powers of anticipating the future or of telepathic communication with other minds are, he says, concepts

“...the possibility of which is altogether groundless, as they cannot be based on experience and its known laws, and without such confirmation are arbitrary combinations of thoughts, which, although indeed free from contradiction, can make no claim to objective reality and so to the possibility of an object such as we here profess to think.”[1265]

The mathematical examples which Kant gives in A 223 = B 271[1266] are no less misleading. The concept of a triangle can, it is implied, be determined as possible in terms of the first Postulate, since it harmonises with a formal condition of experience, namely, space. This is true only if it be granted that construction in space can be executed absolutely a priori, in independence of all sense-experience. Such is, of course, Kant’s most usual view; and to that extent the argument is consistent. Mathematical concepts will from this point of view represent the only possible exception to the general statement that the formal conditions of experience constitute a criterion of possibility for no concepts save themselves. Kant’s final conclusion is clearly and explicitly stated in the following terms:

“I leave aside everything the possibility of which can be derived only from its reality in experience, and have here in view only the possibility of things through a priori concepts; and I maintain the thesis that the possibility of such things can never be established from such concepts taken in and by themselves, but only when they are viewed as formal and objective conditions of experience in general.”[1267]

We are now in a position to appreciate the reasons which have induced Adickes to regard the text as of composite origin.[1268] Adickes argues that Kant’s original intention was to treat the three concepts together, showing that they can be defined only in empirical terms, and that their significance is consequently limited to the world of appearance. Such is the content of the first, second, fourth (excepting the first sentence), and fifth paragraphs. No attempt is made to separate the three Postulates, and the term possibility is throughout employed exclusively as referring to objective reality. (In the third paragraph it is used in both senses.) The other paragraphs were, according to Adickes’ theory, added later, when Kant unfortunately resolved to fulfil more exactly the requirements of his architectonic. That involved the formulation of three separate Postulates, with all the many evil consequences which that attempt carried in its train. He must then have interpolated the third paragraph, added the first sentence to the fourth paragraph, corrected the too extensive sweep of the older paragraphs through the introduction of the sixth paragraph, further supplemented the exposition of the first Postulate by the seventh paragraph, and added independent treatments of the postulates of actuality and necessity. This may seem a very complicated and hazardous hypothesis; but careful examination of the text, with due recognition of the confused character of the argument as it stands, will probably convince the reader that Adickes is in the right.

Second Postulate.[1269]—Perception is necessary to all determination of actuality. The actual is either itself given in perception or can be shown, in accordance with the Analogies, to stand within the unity of objective experience, in connection with what is thus given. So long as Kant expresses himself in these terms his statements are entirely valid. Nothing which cannot be shown to be bound up with the contingent material of sense-experience can be admitted as actual. He proceeds, however, to give a definition of actuality which entirely omits all reference to the Analogies, and which is open to the same fundamental criticism as his characterisation of possibility in the first Postulate. Though the earlier statements give due recognition both to the material content and to the relational forms constitutive of complete experience, Kant now contrasts the mere or bare (blosser) concept and the given perception in a manner which suggests the unfortunate distinction drawn in the Prolegomena, and repeated in the second edition of the Critique, between judgments of perception and judgments of experience.[1270] Kant’s reference to “the mere concept of a thing”[1271] is on the same lines as the opening paragraph of the section. However complete the concept may be, it yields not the least ground for deciding as to the existence of its object.