things themselves on behalf of the determinant Judgement. It is here not at all requisite to prove that such an _intellectus archetypus_ is possible, but only that we are led to the Idea of it,--which contains no contradiction,--in contrast to our discursive Understanding which has need of images (_intellectus ectypus_) and to the contingency of its constitution. If we consider a material whole, according to its form, as a product of the parts with their powers and faculties of combining with one another (as well as of bringing in foreign materials), we represent to ourselves a mechanical mode of producing it. But in this way no concept emerges of a whole as purpose, whose internal possibility presupposes throughout the Idea of a whole on which depend the constitution and mode of action of the parts, as we must represent to ourselves an organised body. It does not follow indeed, as has been shown, that the mechanical production of such a body is impossible; for to say so would be to say that it would be impossible (contradictory) for _any Understanding_ to represent to itself such a unity in the connexion of the manifold, without the Idea of the unity being at the same time its producing cause, _i.e._ without designed production. This, however, would follow in fact if we were justified in regarding material beings as things in themselves. For then the unity that constitutes the ground of the possibility of natural formations would be simply the unity of space. But space is no real ground of the products, but only their formal condition, although it has this similarity to the real ground which we seek that in it no part can be determined except in relation to the whole (the representation of which therefore lies at the ground of the possibility of the parts). But now it is at least possible to consider the material world as mere phenomenon, and to think as its substrate something like a thing in itself (which is not phenomenon), and to attach to this a corresponding intellectual intuition (even though it is not ours). Thus there would be, although incognisable by us, a supersensible real ground for nature, to which we ourselves belong. In this we consider according to mechanical laws what is necessary in nature regarded as an object of Sense; but we consider according to teleological laws the agreement and unity of its particular laws and its forms--which in regard to mechanism we must judge contingent--regarded as objects of Reason (in fact the whole of nature as a system). Thus we should judge nature according to two different kinds of principles without the mechanical way of explanation being shut out by the teleological, as if they contradicted one another.