The fact seems to be that the thought of synthesis in no way helps to elucidate the nature of knowing, and that the mistake in principle which underlies Kant's view lies in the implicit supposition that it is possible to elucidate the nature of knowledge by means of something other than itself. Knowledge is _sui generis_ and therefore a 'theory' of it is impossible. Knowledge is simply knowledge, and any attempt to state it in terms of something else must end in describing something which is not knowledge.[45] [45] Cf. p. 124. CHAPTER X THE SCHEMATISM OF THE CATEGORIES As has already been pointed out,[1] the _Analytic_ is divided into two parts, the _Analytic of Conceptions_, of which the aim is to discover and vindicate the validity of the categories, and the _Analytic of Principles_, of which the aim is to determine the use of the categories in judgement. The latter part, which has now to be considered, is subdivided into two. It has, according to Kant, firstly to determine the sensuous conditions under which the categories are used, and secondly to discover the _a priori_ principles involved in the categories, as exercised under these sensuous conditions, such, for instance, as the law that all changes take place according to the law of cause and effect. The first problem is dealt with in the chapter on the 'schematism of the pure conceptions of the understanding', the second in the chapter on the 'system of all principles of the pure understanding'. [1] p. 141.