prove it.
In order to convince ourselves of the correctness of this Deduction of the concept before us, and the necessity of assuming it as a transcendental principle of cognition, just consider the magnitude of the problem. The problem, which lies a priori in our Understanding, is to make a connected experience out of given perceptions of a nature containing at all events an infinite variety of empirical laws. The Understanding is, no doubt, in possession a priori of universal laws of nature, without which nature could not be an object of experience; but it needs in addition a certain order of nature in its particular rules, which can only be empirically known and which are, as regards the Understanding, contingent. These rules, without which we could not proceed from the universal analogy of a possible experience in general to the particular, must be thought by it as laws (i.e. as necessary), for otherwise they would not constitute an order of nature; although their necessity can never be cognised or comprehended by it. Although, therefore, the Understanding can determine nothing a priori in respect of Objects, it must, in order to trace out these empirical so-called laws, place at the basis of all reflection upon Objects an a priori principle, viz. that a cognisable order of nature is possible in accordance with these laws. The following propositions express some such principle. There is in nature a subordination of genera and species comprehensible by us. Each one approximates to some other according to a common principle, so that a transition from one to another and so on to a higher genus may be possible. Though it seems at the outset unavoidable for our Understanding to assume different kinds of causality for the specific differences of natural operations, yet these different kinds may stand under a small number of principles, with the investigation of which we have to busy ourselves. This harmony of nature with our cognitive faculty is presupposed a priori by the Judgement, on behalf of its reflection upon nature in accordance with its empirical laws; whilst the Understanding at the same time cognises it objectively as contingent, and it is only the Judgement that ascribes it to nature as a trancendental purposiveness (in relation to the cognitive faculty of the subject). For without this presupposition we should have no order of nature in accordance with empirical laws, and consequently no guiding thread for an experience ordered by these in all their variety, or for an investigation of them.
For it might easily be thought that, in spite of all the uniformity of natural things according to the universal laws, without which we should not have the form of an empirical cognition in general, the specific variety of the empirical laws of nature including their effects might yet be so great, that it would be impossible for our Understanding, to detect in nature a comprehensible order; to divide its products into genera and species, so as to use the principles which explain and make intelligible one for the explanation and comprehension of another; or out of such confused material (strictly we should say, so infinitely various and not to be measured by our faculty of comprehension) to make a connected experience.
The Judgement has therefore also in itself a principle a priori of the possibility of nature, but only in a subjective aspect; by which it prescribes, not to nature (autonomy), but to itself (heautonomy) a law for its reflection upon nature. This we might call the law of the specification of nature in respect of its empirical laws. The Judgement does not cognise this a priori in nature, but assumes it on behalf of a natural order cognisable by our Understanding in the division which it makes of the universal laws of nature when it wishes to subordinate to these the variety of particular laws. If then we say that nature specifies its universal laws according to the principles of purposiveness for our cognitive faculty, i.e. in accordance with the necessary business of the human Understanding of finding the universal for the particular which perception offers it, and again of finding connexion for the diverse (which however is a universal for each species) in the unity of a principle,—we thus neither prescribe to nature a law, nor do we learn one from it by observation (although such a principle may be confirmed by this means). For it is not a principle of the determinant but merely of the reflective Judgement. We only require that, be nature disposed as it may as regards its universal laws, investigation into its empirical laws may be carried on in accordance with that principle and the maxims founded thereon, because it is only so far as that holds that we can make any progress with the use of our Understanding in experience, or gain knowledge.
VI. OF THE COMBINATION OF THE FEELING OF PLEASURE WITH THE CONCEPT OF THE PURPOSIVENESS OF NATURE.
The thought harmony of nature in the variety of its particular laws with our need of finding universality of principles for it, must be judged as contingent in respect of our insight, but yet at the same time as indispensable for the needs of our Understanding, and consequently as a purposiveness by which nature is harmonised with our design, which, however, has only knowledge for its aim. The universal laws of the Understanding, which are at the same time laws of nature, are just as necessary (although arising from spontaneity) as the material laws of motion. Their production presupposes no design on the part of our cognitive faculty, because it is only by means of them that we, in the first place, attain a concept of what the cognition of things (of nature) is, and attribute them necessarily to nature as Object of our cognition in general. But, so far as we can see, it is contingent that the order of nature according to its particular laws, in all its variety and heterogeneity possibly at least transcending our comprehension, should be actually conformable to these [laws]. The discovery of this [order] is the business of the Understanding which is designedly borne towards a necessary purpose, viz. the bringing of unity of principles into nature, which purpose then the Judgement must ascribe to nature, because the Understanding cannot here prescribe any law to it.
The attainment of that design is bound up with the feeling of pleasure, and since the condition of this attainment is a representation a priori,—as here a principle for the reflective Judgement in general,—therefore the feeling of pleasure is determined by a ground a priori and valid for every man, and that merely by the reference of the Object to the cognitive faculty, the concept of purposiveness here not having the least reference to the faculty of desire. It is thus quite distinguished from all practical purposiveness of nature.
In fact, although from the agreement of perceptions with laws in accordance with universal natural concepts (the categories), we do not and cannot find in ourselves the slightest effect upon the feeling of pleasure, because the Understanding necessarily proceeds according to its nature without any design; yet, on the other hand, the discovery that two or more empirical heterogeneous laws of nature may be combined under one principle comprehending them both, is the ground of a very marked pleasure, often even of an admiration, which does not cease, though we may be already quite familiar with the objects of it. We no longer find, it is true, any marked pleasure in the comprehensibility of nature and in the unity of its divisions into genera and species, whereby are possible all empirical concepts, through which we cognise it according to its particular laws. But this pleasure has certainly been present at one time, and it is only because the commonest experience would be impossible without it that it is gradually confounded with mere cognition and no longer arrests particular attention. There is then something in our judgements upon nature which makes us attentive to its purposiveness for our Understanding—an endeavour to bring, where possible, its dissimilar laws under higher ones, though still always empirical—and thus, if successful, makes us feel pleasure in that harmony of these with our cognitive faculty, which harmony we regard as merely contingent. On the other hand, a representation of nature would altogether displease, by which it should be foretold to us that in the smallest investigation beyond the commonest experience we should meet with a heterogeneity of its laws, which would make the union of its particular laws under universal empirical laws impossible for our Understanding. For this would contradict the principle of the subjectively-purposive specification of nature in its genera, and also of our reflective Judgement in respect of such principle.
This presupposition of the Judgement is, however, at the same time so indeterminate as to how far that ideal purposiveness of nature for our cognitive faculty should be
