(b) The Logical Use of Reason[1378]
In this subsection Kant introduces the distinction between understanding and judgment which he has sought to justify in A 130 ff. = B 169 ff. By showing that inference determines the relation between a major premiss (due to the understanding) and the condition defined in the minor premiss (due to the faculty of judgment), he professes to obtain justification for classifying the possible forms of reasoning according to the three categories of relation. The general remark is added that the purpose of Reason, in its logical employment as inference, is to obtain the highest possible unity, through subsumption of all multiplicity under the smallest possible number of universals.
(c) The Pure Use of Reason[1379]
Kant here states the alternatives between which the Dialectic has to decide. Is Reason merely formal, arranging given material according to given forms of unity, or is it a source of principles which prescribe higher forms of unity than any revealed by actual experience? Further examination of its formal and logical procedure constrains us, Kant asserts, to adopt the latter position; and at the same time indicates how those principles must be interpreted, namely, as subjective laws that apply not to objects but only to the activities of the understanding.
In the first place, a syllogism is not directly concerned with intuitions, but only with concepts and judgments. This may be taken as indicating that pure Reason relates to objects only mediately by way of understanding and its judgments. The unity which it seeks is higher than that of any possible experience; it is a unity which must be constructed and cannot be given.[1380]
Secondly, Reason in its logical use seeks the universal condition of its judgment; and when such is not found in the major premiss proceeds to its discovery through a regressive series of prosyllogisms. In so doing it is obviously determined by a principle expressive of the peculiar function of Reason in its logical employment, namely, that for the conditioned knowledge of understanding the unconditioned unity in which that knowledge may find completion must be discovered. Such a principle is synthetic, since from analysis of the conception of the conditioned we can discover its relation to a condition, but never its relation to the unconditioned. That is a notion which falls entirely outside the sphere of the understanding, and which therefore demands a separate enquiry. How is the above a priori synthetic principle to be accounted for, if it cannot be traced to understanding? Has it objective, or has it merely subjective validity? And lastly, what further synthetic principles can be based upon it? Such are the questions to which Critical Dialectic must supply an answer. This Dialectic will be composed of two main divisions, the doctrine of “the transcendent concepts of pure Reason” and the doctrine of “transcendent and dialectical inferences of Reason.”
BOOK I
THE CONCEPTS OF PURE REASON[1381]
The distinction here drawn between concepts obtained by reflection and concepts gained by inference is a somewhat misleading mode of stating the fact that, whereas the categories of understanding condition experience and so make possible the unity of consciousness necessary to all reflection, or, in other words, are conditions of the material supplied for inference, the concepts of Reason are Ideal constructions which though in a certain sense resting upon experience none the less transcend it. The function of the Ideas is to organise experience in its totality; that of the categories is to render possible the sense-perceptions constitutive of its content. The former refer to the unconditioned, and though that is a conception under which everything experienced is conceived to fall, it represents a type of knowledge to which no actual experience can ever be adequate.
Conceptus ratiocinati—conceptus ratiocinantes. When such transcendent concepts possess “objective validity,” they are correctly inferred, and may be entitled conceptus ratiocinati. If, on the other hand, they are due to merely sophistical[1382] reasoning, they are purely fictitious, conceptus ratiocinantes. This distinction raises many difficulties. Kant’s intention cannot be to deny that the conceptus ratiocinati are “mere Ideas” (entia rationis)[1383]—for such is his avowed and constant contention—or that the inference to them is dialectical and is based upon a transcendental illusion. Two alternatives are open. He may mean that they are only valid when the results of such inference are Critically reinterpreted, and when the function of the Ideas is realised to be merely regulative; or his intention may be to mark off the Ideas, strictly so-called, which are inevitable and beneficial products of Reason, from the many idle and superfluous inventions of speculative thought. Kant’s concluding remark, that the questions at issue can be adequately discussed only at a later stage, may be taken as in the nature of an apology for the looseness of these preliminary statements, and as a warning to the reader not to insist upon them too absolutely. The participles ratiocinati and ratiocinantes[1384] are of doubtful latinity. The distinction of meaning here imposed upon them has not been traced in any other writer, and is perhaps Kant’s own invention.[1385]
SECTION I
IDEAS IN GENERAL[1386]