THE ORIGIN OF OUR IDEAS 



lution, the master-key, that has revealed the solu- 

 tion. Spencer examined the history of the in- 

 dividual mind in the light of the history of the 

 racial mind. It is, indeed, true that we have no 

 innate ideas, but it is untrue that the mind is a 

 tabula rasa ; for it is a general biological truth that 

 "function makes structure," and the experience 

 of our countless ancestors has registered itself in 

 the anatomical configuration of the human brain, 

 each new specimen of which is thus neither a 

 storehouse of innate ideas nor a blank sheet of 

 sensitive paper, but a structure which is preformed 

 for the reception of certain ideas and can express 

 them so soon as its converse with phenomena be- 

 gins. 1 



The best instance of what I conceive to be the 

 true reading of the Spencerian explanation is af- 

 forded by the idea of space as having three di- 

 mensions. I have elsewhere advanced the theory 

 that the structure of the semicircular canals of 

 the internal ear, which are arranged, on each side 

 of the head, in a set of three that correspond to 

 the three dimensions of space, as we conceive it, 

 is an argument in favor of the objective truth 

 of our conception. Evolution has unquestion- 



1 1 have to confess that, in a previous volume, I have vent- 

 ured to describe this conception of Spencer's as only a half- 

 truth. What I now believe to be an unjustifiable criticism 

 was due, as are so many criticisms on Spencer, to my having 

 paid undue attention to his critics and soi-disant exponents and 

 too little to his own words. This is offered as an explanation, 

 not as an excuse. 



217 



