THE TEST OF TRUTH 



assumes that conceptions may have been framed 

 of which the elements have never been joined 

 together in experience. Yet of all possible psy- 

 chological theorems there is none, I suppose, 

 which, when overtly stated, Mr. Mill would more 

 emphatically deny than this. To see Mr. Mill 

 unwittingly arrayed in the lists against the expe- 

 rience-theory is indeed a singular spectacle ; but 

 it is only one instance out of many of the way 

 in which that theory has suffered from its as- 

 sociation with empiricism. When in a future 

 chapter we come to treat of the evolution of 

 intelligence, we shall see that Mr. Spencer was 

 the first to penetrate to the very core of the 

 experience-philosophy when he perceived that 

 the deepest warrant for the perfect conformity 

 of a given proposition with experience is the 

 unthinkableness of the counter-proposition.^ 



^ Since my final revision of this chapter, I find the case 

 thus admirably put into a nutshell by Mr. Lewes, in his now 

 forthcoming work. Problems of Life and Mindy vol. i. p. 

 396: **The arguments which support the a priori view 

 have been ingeniously thrown into this syllogism by Mr. 

 Killick : The necessary truth of a proposition is a mark of its 

 not being derived from Experience. (Experience cannot in- 

 form us of what must be : ) The incoiiceiv ability of the con- 

 tradictory is the mark of the necessary truth of a proposition : 

 Therefore the inconceivability of its contradictory is a mark 

 of a proposition not being derived from Experience. — This 

 syllogism is perfect in form, but has a radical defect in its 

 terms. The inconceivability of a contradictory results from 



99 



