Examination of this section as a whole (and the same is true of the immediately following section) justifies the conclusion that at the time when it was written Kant regarded the Ideas of Reason as having a purely and exclusively regulative function, and consequently as exhausting their inherent meaning in their empirical reference. He regards them as entirely lacking in metaphysical significance. They are invented by Reason for Reason’s own satisfaction, and must therefore yield in their internal content the explanation of their existence, and must also supply a complete and thorough answer to all problems which are traceable to them. A dogmatic (i.e. ontological) solution of the antinomies is, as we have already found, impossible; the Critical solution considers the question subjectively,
“...in accordance with the foundation of the knowledge upon which it is based.”[1538] “For your object is only in your brain, and cannot be given outside it; so that you have only to take care to be at one with yourself, and to avoid the amphiboly which transforms your Idea into a supposed representation of an object which is empirically given and therefore to be known according to the laws of experience.”[1539]
Kant’s argument in proof of this purely subjective interpretation of the Ideas consists in showing that they are not presented in any given appearances, and are not even necessary to explain appearances. The unconditioned, whether of quantity, of division, or of origination, has nothing to do with any experience, whether actual or possible.
“You would not, for instance, in any wise be able to explain the appearances of a body better, or even differently, if you assumed that it consists either of simple or of inexhaustibly composite parts; for neither a simple appearance nor an infinite composition can ever come before you. Appearances demand explanation only in so far as the conditions of their explanation are given in perception, [and the unconditioned can never be so given].”[1540]
This standpoint, at once sceptical and empirical, is further developed in the next section.
SECTION V
SCEPTICAL REPRESENTATION OF THE COSMOLOGICAL QUESTIONS[1541]
Applying the “sceptical method,”[1542] Kant argues that even supposing one or other party could conclusively establish itself through final refutation of the other, no advantage of any kind would accrue. The victory would be a fruitless one, and the outcome “mere nonsense.”[1543] The sole validity of the Ideas lies in their empirical reference; and yet that reference is one which proves them to be, when objectively interpreted, entirely meaningless. The cosmological Idea is always either too large or too small for any concept of the understanding. No matter what view is taken, the only possible object (viz. that yielded by experience) will not fit into it. If the world has no beginning, or is infinitely divisible, or has no first cause, the regress transcends all empirical concepts; while if the world has a beginning, is composed of simple parts, and has a first cause, it is too small for the concepts through which alone it can be experienced. In other words, the cosmological Ideas are always either too large or too small for the empirical regress, and therefore stand condemned by sense-experience, which can alone impart relation to an object, i.e. truth and meaning to any concept. For, as Kant explicitly states, we must not reverse this relation and condemn empirical concepts, as being in the one case too small, and in the other case too large for the Idea. Experience, not Ideas, is the criterion alike of reality and of truth.
“The possible empirical concept is, therefore, the standard by which we must judge whether the Idea is mere Idea and thought-entity (Gedankending), or whether it finds its object in the world.”[1544]
When two things are compared, that for the sake of which the other exists is the sole proper standard. We do not say “that a man is too long for his coat, but that the coat is too short for the man.”[1545] We are thus confirmed in the view that the antinomies rest upon a false view of the manner in which the object of the cosmological Ideas can be given; and are set upon the track, followed out in the next section, of the illusion to which they are due.
This reduction of the Ideas to mere thought-entities is one of the two alternative views which, as we have already stated,[1546] compete with one another throughout the entire Dialectic. We may, for instance, compare the above explanation of the conflict between the Ideas and experience with that given in A 422 = B 450. In the latter passage the antinomies are traced to a conflict between Reason and understanding. If the unity is adequate to the demands of Reason, it is too great for the understanding; if it is adequate to the understanding, it is too small for Reason. Kant does not here allow that the claims of Reason are ipso facto condemned through the incapacity of experience to fulfil them. On the contrary, he implies that it is through the Ideas that we come to realise the merely phenomenal character of everything experienced.