ra. i.] MATTER, MOTION, AND FORCE. 287 



law of causation is said to be established. Mr. Mill only 

 emphasizes the incompleteness of his view when he repudiates 

 the inconceivability-test as evidence of the law in question. 

 This point has been already so fully discussed that little 

 more need to be said about it here. When, in a future 

 chapter, we come to deal especially with the evolution of 

 intelligence, we shall see that Mr. Mill's inadequate treat- 

 ment of this subject is due to imperfect mastery of the 

 Doctrine of Evolution. We shall see that the so-called 

 experience-philosophy is both wider and deeper than English 

 psychologists, from Hobbes to Mill, have imagined. We 

 shall see that not only our acquired knowledge, but even the 

 inherited constitution of our minds, is the product of 

 accumulated and integrated experiences, partly personal but 

 chiefly ancestral. Upon this wider ground we shall find 

 ourselves able to dwell in peace with our old foes, the 

 intuitionalists, since it will be seen that the very intuitions 

 upon which they rightly insist as inexplicable from individual 

 experience are nevertheless explicable from the organized 

 experiences of countless generations. And the conclusion 

 will then assert itself, with redoubled emphasis, that the 

 axiom of the persistence of force, being the product of the 

 entire intercourse between subject and object, since the dawn 

 of intelligence, must have the highest warrant which any 

 axiom can have. 



Let us for the present, however, content ourselves with 

 reproducing the psychological argument by which Mr. 

 Spencer clinches his demonstration of the necessity which 

 we are under to conceive of force as persistent. " The inde- 

 structibility -of matter and the continuity of motion, we saw 

 to be really corollaries from the impossibility of establishing 

 in thought a relation between something and nothing. What 

 we call the establishment of a relation in thought, is the 

 passage of the substance of consciousness from one form into 

 another. To think of something becoming nothing, would 



