Nature, as a whole, no less than in its different productions, will, of necessity, appear as a work produced with consciousness, and, at the same time, as a production of the blindest mechanism. It is the result of purpose, without being demonstrable as such. The philosophy of the aims of Nature, or teleology, is therefore the required point of union between theoretical and practical philosophy. D. Hitherto, we have postulated only in general terms the identity of the unconscious activity, which has produced Nature, and the conscious activity, which exhibits itself in volition, without having decided where the principle of this activity lies—whether in Nature or in us. Now, the system of knowledge can be regarded as complete only when it reverts to its principle. Transcendental philosophy, therefore, could be complete only when that identity—the highest solution of its whole problem—could be demonstrated in its principle, the _Ego_. It is therefore postulated that, in the subjective—in the consciousness itself—that activity, at once conscious and unconscious, can be shown. Such an activity can be no other than the _æsthetic_, and every work of art can be conceived only as the product of such. The ideal work of art and the real world of objects are therefore products of one and the same activity; the meeting of the two (the conscious and the unconscious) _without_ consciousness, gives the real—_with_ consciousness, the æsthetic world. The objective world is only the primal, still unconscious, poetry of the mind; the universal _organum_ of philosophy, the key-stone of its whole arch, is the philosophy of art. IV.—ORGAN OF TRANSCENDENTAL PHILOSOPHY. 1. The only immediate object of transcendental consideration is the subjective (II.); the only organ for philosophizing in this manner is the _inner sense_, and its object is such that, unlike that of mathematics, it can never become the object of external intuition. The object of mathematics, to be sure, exists as little outside of knowledge, as that of philosophy. The whole existence of mathematics rests on intuition; it exists, therefore, only in intuition; and this intuition itself is an external one. In addition to this, the mathematician never has to deal immediately with the intuition—the construction itself—but only with the thing constructed, which, of course, can be exhibited outwardly; whereas the philosopher looks only at the act of construction itself, which is purely an internal one.