MATHEMATICS VERSUS PSYCHOLOGY II 



of substances, whether material or spiritual, finite or infinite, 

 are inadequate i. e., fail to correspond accurately to their qb- 

 / jects. In the second place, his theory of intuition differed from 

 that of the rationalists in a way which brought into prominence 

 a new problem for science. According to the rationalists, the 

 intuitive truth presents itself to reason as a whole, subject, 

 predicate, and all. According to Locke, the ideas involved in 

 such a truth must, like all other ideas, be originally derived from 

 experience, however they may have since been modified by proc- 

 esses of abstraction and composition; all that intuition gives 

 is the connection between them. Locke was thus led to under- 

 take to show in detail how various ideas and classes of ideas 

 especially those which had been generally regarded as intuitive 

 are indeed derived from our outer and inner experience, or, as 

 he puts it, from sensation and reflection. And though his 

 methods of research were primitively crude, he succeeded in en- 

 dowing modern psychology with a problem of the first impor- 

 tance : the origin of our ideas. 



As mathematics was the science of sciences for rationalism, all 



other sciences being either extensions or special applications of 

 this one; so for empiricism psychology became the science of 

 sciences, central and fundamental, its method being the organon 

 of philosophy. There had been psychology before this, occasion- 

 ally (as in the early chapters of Hobbes's Leviathan) containing 

 suggestions whose full value has only recently been realized. 

 But for the most part it was a very superficial affair, a formula- 

 tion of definitions of various mental processes, based on no evi- 

 dence except undisciplined observation. The elementary dis- 

 tinction between the logical implications of an idea or a passion 

 and its actual structure in consciousness was either unrecognized 

 or neglected. Psychology is of all sciences the least amenable 

 to deductive treatment, the one in which even today it is most 

 necessary to keep one's eye fixed on the phenomena to be de- 

 scribed and declare simply and plainly what one finds there. 

 No modern man before Locke had done this, and Locke himself 



