oh. v.J THE TWO METHODS. 101 



justified in declaring that "all that has been written on 

 method [from the scientific point of view] is imperilled if 

 there can be any valid evidence for the existence of an 

 avenue through which knowledge may be reached without 

 recourse to experience." Granting the a priori origin of 

 necessary truths, the validity of the subjective method is 

 established, at least so far as transcendental inquiries are 

 concerned. It is therefore interesting to observe the remark- 

 able similarity between the positions held respectively by 

 Plato, Descartes, and Kant, with reference to this twofold 

 question. In each case the psychological problem is to 

 explain the existence of knowledge, or at least of concep- 

 tive faculty, that is apparently congenital, and that is also 

 apparently inexplicable as the product of individual expe- 

 rience. How does the uneducated youth come by his rapid 

 intuition of space-relations ? Plato, as we have seen, replies 

 with his hypothesis of reminiscence, Descartes with his 

 hypothesis of innate ideas, and Kant with his hypothesis 

 of a priori forms of thought ; and between the three answers, 

 in spite of the wide superficial divergences, how striking is 

 the fundamental similarity ! We shall hereafter see how the 

 Doctrine of Evolution, proceeding strictly upon the objective 

 method, supplies us with an interpretation which adequately 

 accounts for the phenomena, but which leaves no room for 

 the inferences which metaphysicians, from Plato to Kant, 

 have founded thereon. Meanwhile, it has already been 

 sufficiently proved that the universality and necessity of 

 unconditional propositions, whether relating to space-relations 

 or to any other relations whatever, must inevitably result 

 from absolute uniformity in the organic registration of 

 experiences, and therefore docs not involve any a priori 

 element. 



For the present, returning to Plato, let us note some of the 

 results to which his method not unnaturally ltd him, espe- 

 cially as we shall thus perceive the true affiliation of modern 



