so as to make possible a system of experience according to particular laws of nature. Not as if, in this way, such an Understanding must be assumed as actual (for it is only our reflective Judgement to which this Idea serves as a principle—for reflecting, not for determining); but this faculty thus gives a law only to itself and not to nature.
Now the concept of an Object, so far as it contains the ground of the actuality of this Object, is the purpose; and the agreement of a thing with that constitution of things, which is only possible according to purposes, is called the purposiveness of its form. Thus the principle of Judgement, in respect of the form of things of nature under empirical laws generally, is the purposiveness of nature in its manifoldness. That is, nature is represented by means of this concept, as if an Understanding contained the ground of the unity of the manifold of its empirical laws.
The purposiveness of nature is therefore a particular concept, a priori, which has its origin solely in the reflective Judgement. For we cannot ascribe to natural products anything like a reference of nature in them to purposes; we can only use this concept to reflect upon such products in respect of the connexion of phenomena which is given in nature according to empirical laws. This concept is also quite different from practical purposiveness (in human art or in morals), though it is certainly thought according to the analogy of these last.
V. THE PRINCIPLE OF THE FORMAL PURPOSIVENESS OF NATURE IS A TRANSCENDENTAL PRINCIPLE OF JUDGEMENT.
A transcendental principle is one by means of which is represented, a priori, the universal condition under which alone things can be in general Objects of our cognition. On the other hand, a principle is called metaphysical if it represents the a priori condition under which alone Objects, whose concept must be empirically given, can be further determined a priori. Thus the principle of the cognition of bodies as substances, and as changeable substances, is transcendental, if thereby it is asserted that their changes must have a cause; it is metaphysical if it asserts that their changes must have an external cause. For in the former case bodies need only be thought by means of ontological predicates (pure concepts of Understanding), e.g. substance, in order to cognise the proposition a priori; but in the latter case the empirical concept of a body (as a movable thing in space) must lie at the basis of the proposition, although once this basis has been laid down, it may be seen completely a priori that this latter predicate (motion only by external causes) belongs to body.—Thus, as I shall presently show, the principle of the purposiveness of nature (in the manifoldness of its empirical laws) is a transcendental principle. For the concept of Objects, so far as they are thought as standing under this principle, is only the pure concept of objects of possible empirical cognition in general and contains nothing empirical. On the other hand, the principle of practical purposiveness, which must be thought in the Idea of the determination of a free will, is a metaphysical principle; because the concept of a faculty of desire as a will must be given empirically (i.e. does not belong to transcendental predicates). Both principles are, however, not empirical, but a priori; because for the combination of the predicate with the empirical concept of the subject of their judgements no further experience is needed, but it can be apprehended completely a priori.
That the concept of a purposiveness of nature belongs to transcendental principles can be sufficiently seen from the maxims of the Judgement, which lie at the basis of the investigation of nature a priori, and yet do not go further than the possibility of experience, and consequently of the cognition of nature—not indeed nature in general, but nature as determined through a variety of particular laws. These maxims present themselves in the course of this science often enough, though in a scattered way, as sentences of metaphysical wisdom, whose necessity we cannot demonstrate from concepts. “Nature takes the shortest way (lex parsimoniae); at the same time it makes no leaps, either in the course of its changes or in the juxtaposition of specifically different forms (lex continui in natura); its great variety in empirical laws is yet unity under a few principles (principia praeter necessitatem non sunt multiplicanda),” etc.
If we propose to set forth the origin of these fundamental propositions and try to do so by the psychological method, we violate their sense. For they do not tell us what happens, i.e. by what rule our cognitive powers actually operate, and how we judge, but how we ought to judge; and this logical objective necessity does not emerge if the principles are merely empirical. Hence that purposiveness of nature for our cognitive faculties and their use, which is plainly apparent from them, is a transcendental principle of judgements, and needs therefore also a Transcendental Deduction, by means of which the ground for so judging must be sought in the sources of cognition a priori.
We find in the grounds of the possibility of an experience in the very first place something necessary, viz. the universal laws without which nature in general (as an object of sense) cannot be thought; and these rest upon the Categories, applied to the formal conditions of all intuition possible for us, so far as it is also given a priori. Now under these laws the Judgement is determinant, for it has nothing to do but to subsume under given laws. For example, the Understanding says that every change has its cause (universal law of nature); the transcendental Judgement has nothing further to do than to supply a priori the condition of subsumption under the concept of the Understanding placed before it, i.e. the succession [in time] of the determinations of one and the same thing. For nature in general (as an object of possible experience) that law is cognised as absolutely necessary.—But now the objects of empirical cognition are determined in many other ways than by that formal time-condition, or, at least as far as we can judge a priori, are determinable. Hence specifically different natures can be causes in an infinite variety of ways, as well as in virtue of what they have in common as belonging to nature in general; and each of these modes must (in accordance with the concept of a cause in general) have its rule, which is a law and therefore brings necessity with it, although we do not at all comprehend this necessity, in virtue of the constitution and the limitations of our cognitive faculties. We must therefore think in nature, in respect of its merely empirical laws, a possibility of infinitely various empirical laws, which are, as far as our insight goes, contingent (cannot be cognised a priori), and in respect of which we judge nature, according to empirical laws and the possibility of the unity of experience (as a system according to empirical laws), to be contingent. But such a unity must be necessarily presupposed and assumed, for otherwise there would be no thoroughgoing connexion of empirical cognitions in a whole of experience. The universal laws of nature no doubt furnish such a connexion of things according to their kind as things of nature in general, but not specifically, as such particular beings of nature. Hence the Judgement must assume for its special use this principle a priori, that what in the particular (empirical) laws of nature is from the human point of view contingent, yet contains a unity of law in the combination of its manifold into an experience possible in itself—a unity not indeed to be fathomed by us, but yet thinkable. Consequently as the unity of law in a combination, which we cognise as contingent in itself, although in conformity with a necessary design (a need) of Understanding, is represented as the purposiveness of Objects (here of nature); so must the Judgement, which in respect of things under possible (not yet discovered) empirical laws is merely reflection, think of nature in respect of the latter according to a principle of purposiveness for our cognitive faculty, which then is expressed in the above maxims of the Judgement. This transcendental concept of a purposiveness of nature is neither a natural concept nor a concept of freedom, because it ascribes nothing to the Object (of nature), but only represents the peculiar way in which we must proceed in reflection upon the objects of nature in reference to a thoroughly connected experience, and is consequently a subjective principle (maxim) of the Judgement. Hence, as if it were a lucky chance favouring our design, we are rejoiced (properly speaking, relieved of a want), if we meet with such systematic unity under merely empirical laws; although we must necessarily assume that there is such a unity without our comprehending it or being
