That it does not belong to Theology as a part thereof, although it may be made of the most important use therein, is self-evident. For it has as its objects, natural productions, and their cause, and although it refers at the same time to the latter as to a ground lying outside of and beyond nature (a Divine Author), yet it does not do this for the determinant but only for the reflective Judgement in the consideration of nature (in order to guide our judgement on things in the world by means of such an Idea as a regulative principle, in conformity with the human Understanding). But it appears to belong just as little to Natural Science, which needs determinant and not merely reflective principles in order to supply objective grounds for natural effects. In fact, nothing is gained for the theory of nature or the mechanical explanation of its phenomena by means of its effective causes, by considering them as connected according to the relation of purposes. The exhibition of the purposes of nature in its products, so far as they constitute a system according to teleological concepts, properly belongs only to a description of nature which is drawn up in accordance with a particular guiding thread. Here Reason, no doubt, accomplishes a noble work, instructive and practically purposive in many points of view; but it gives no information as to the origin and the inner possibility of these forms, which is the special business of theoretical Natural Science. Teleology, therefore, as science, belongs to no Doctrine, but only to Criticism; and to the criticism of a special cognitive faculty, viz. Judgement. But so far as it contains principles _a priori_, it can and must furnish the method by which nature must be judged according to the principle of final causes. Hence its Methodology has at least negative influence upon the procedure in theoretical Natural Science, and also upon the relation which this can have in Metaphysic to Theology as its propaedeutic. § 80. _Of the necessary subordination of the mechanical to the teleological principle in the explanation of a thing as a natural purpose_ The _privilege of aiming at_ a merely mechanical method of explanation of all natural products is in itself quite unlimited; but the _faculty of attaining_ thereto is by the constitution of our Understanding, so far as it has to do with things as natural purposes, not only very much limited but also clearly bounded. For, according to a principle of the Judgement, by this process alone nothing can be accomplished towards an explanation of these things; and consequently the judgement upon such products must always be at the same time subordinated by us to a teleological principle.