To the faculty of Reason Kant ascribes what he entitles Ideas. The Ideas differ from space, time, and the categories in being not “constitutive” but “regulative.” They demand an _unconditionedness_ of existence and a _completeness_ of explanation which can never be found in actual experience. Their function is threefold. In the first place, they render the mind dissatisfied with the haphazard collocations of ordinary experience, and define the goal for its scientific endeavours. Secondly, they determine for us the criteria that distinguish between truth and falsity.[47] And thirdly, in so doing, they likewise make possible the distinction between appearance and reality, revealing to us an irreconcilable conflict between the ultimate aims of science and the human conditions, especially the spatial and temporal conditions under which these aims are realised. The Ideas of Reason are the second main factor in the “antinomies.” The problem of the _Critique_, the analysis of our awareness of meaning, is a single problem, and each of the above elements involves all the others. Kant, however, for reasons into which I need not here enter, has assigned part of the problem to what he entitles the _Transcendental Aesthetic_, and another part to the _Transcendental Dialectic_. Only what remains is dealt with in what is really the most important of the three divisions, the _Transcendental Analytic_. But as the problem is one and indivisible, the discussions in all three sections are condemned to incompleteness save in so far as Kant, by happy inconsistency, transgresses the limits imposed by his method of treatment. The _Aesthetic_ really does no more than prepare the ground for the more adequate analysis of space and time given in the _Analytic_ and _Dialectic_, while the problem of the _Analytic_ is itself incompletely stated until the more comprehensive argument of the _Dialectic_ is taken into account.[48] Thus the statement in the _Aesthetic_ that space and time are _given_ to the mind by the sensuous faculty of receptivity is modified in the _Analytic_ through recognition of the part which the syntheses and concepts of the understanding must play in the construction of these forms; and in the _Dialectic_ their apprehension is further found to involve an Idea of Reason. Similarly, in the concluding chapter of the _Analytic_, in discussing the grounds for distinguishing between appearance and reality, Kant omits all reference to certain important considerations which first emerge into view in the course of the _Dialectic_. Yet, though no question is more vital to Critical teaching, the reader is left under the impression that the treatment given in the _Analytic_ is complete and final.