The Critique of the cognitive faculties, as regards what they can furnish _a priori_, has properly speaking no realm in respect of Objects, because it is not a doctrine, but only has to investigate whether and how, in accordance with the state of these faculties, a doctrine is possible by their means. Its field extends to all their pretensions, in order to confine them within their legitimate bounds. But what cannot enter into the division of Philosophy may yet enter, as a chief part, into the Critique of the pure faculty of cognition in general, viz. if it contains principles which are available neither for theoretical nor for practical use. The natural concepts, which contain the ground of all theoretical knowledge _a priori_, rest on the legislation of the Understanding.--The concept of freedom, which contains the ground of all sensuously-unconditioned practical precepts _a priori_, rests on the legislation of the Reason. Both faculties, therefore, besides being capable of application as regards their logical form to principles of whatever origin, have also as regards their content, their special legislations above which there is no other (_a priori_); and hence the division of Philosophy into theoretical and practical is justified. But in the family of the higher cognitive faculties there is a middle term between the Understanding and the Reason. This is the _Judgement_, of which we have cause for supposing according to analogy that it may contain in itself, if not a special legislation, yet a special principle of its own to be sought according to laws, though merely subjective _a priori_. This principle, even if it have no field of objects as its realm, yet may have somewhere a territory with a certain character, for which no other principle can be valid.