It hence follows that the rational concept of the supersensible substrate of all phenomena in general, or even of that which must be placed at the basis of our arbitrary will in respect of the moral law, viz. of transcendental freedom, is already, in kind, an indemonstrable concept and a rational Idea; while virtue is so, in degree. For there can be given in experience, as regards its quality, absolutely nothing corresponding to the former; whereas in the latter case no empirical product attains to the degree of that causality, which the rational Idea prescribes as the rule. As in a rational Idea the _Imagination_ with its intuitions does not attain to the given concept, so in an aesthetical Idea the _Understanding_ by its concepts never attains completely to that internal intuition which the Imagination binds up with a given representation. Since, now, to reduce a representation of the Imagination to concepts is the same thing as to _expound_ it, the aesthetical Idea may be called an _inexponible_ representation of the Imagination (in its free play). I shall have occasion in the sequel to say something more of Ideas of this kind; now I only note that both kinds of Ideas, rational and aesthetical, must have their principles; and must have them in Reason--the one in the objective, the other in the subjective principles of its employment. We can consequently explain _genius_ as the faculty of _aesthetical Ideas_; by which at the same time is shown the reason why in the products of genius it is the nature (of the subject) and not a premeditated purpose that gives the rule to the art (of the production of the beautiful). For since the beautiful must not be judged by concepts, but by the purposive attuning of the Imagination to agreement with the faculty of concepts in general, it cannot be rule and precept which can serve as the subjective standard of that aesthetical but unconditioned purposiveness in beautiful art, that can rightly claim to please every one. It can only be that in the subject which is nature and cannot be brought under rules or concepts, _i.e._ the supersensible substrate of all his faculties (to which no concept of the Understanding extends), and consequently that with respect to which it is the final purpose given by the intelligible [part] of our nature to harmonise all our cognitive faculties. Thus alone is it possible that there should be _a priori_ at the basis of this purposiveness, for which we can prescribe no objective principle, a principle subjective and yet of universal validity. _Remark II._