exact knowledge. But it is apparent that there are other problems which merit consideration; a complete philosophy includes practice as well as theory; it has to do not only with logic, but with life. And thus the Critique of Practical Reason was written, in which is unfolded the doctrine of man’s freedom standing in sharp contrast with the necessity of natural law. Here, then, it seems at first sight as if we had covered the whole field of human activity. For we have investigated the sources of knowledge, and at the same time have pointed out the conditions of practical life, and have seen that the laws of freedom are just as true in their own sphere as are the laws of nature. But as we reflect on our mental states we find that here no proper account has been given of the phenomena of _feeling_, which play so large a part in experience. And this Kant saw before he had proceeded very far with the Critique of Practical Reason; and in consequence he adopted a threefold classification of the higher mental faculties based on that given by previous psychologists. Knowledge, feeling, desire, these are the three ultimate modes of consciousness, of which the second has not yet been described. And when we compare this with the former triple division which we took up from the Aristotelian logic, we see that the parallelism is significant. Understanding is _par excellence_ the faculty of knowledge, and Reason the faculty of desire (these points are developed in Kant’s first two Critiques). And this suggests that the Judgement corresponds to the feeling of pleasure and pain; it occupies a position intermediate between Understanding and Reason, just as, roughly speaking, the feeling of pleasure is intermediate between our perception of an object and our desire to possess it. And so the Critique of Judgement completes the whole undertaking of criticism; its endeavour is to show that there are _a priori_ principles at the basis of Judgement just as there are in the case of Understanding and of Reason; that these principles, like the principles of Reason, are not constitutive but only regulative of experience, _i.e._ that they do not teach us anything positive about the characteristics of objects, but only indicate the conditions under which we find it necessary to view them; and lastly, that we are thus furnished with an _a priori_ philosophy of pleasure.