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 able to prove it.