EVOLUTION THE MASTER-KEY 



generally are developed, both in the individual 

 and in the race, from the outermost or cutaneous 

 layer of the body. The inference is that our 

 nervous systems are essentially means for appre- 

 ciation of and response to our environments. 

 Hence the human intellect, as Spencer says, has 

 been developed "by and for converse with phe- 

 nomena." The evolutionary or genetic manner 

 of looking at man's brain suggests to us the bio- 

 logical or anatomical explanation of the conclu- 

 sion reached by many other avenues of inquiry, 

 that human knowledge can never be more than 

 phenomenal (i. e., of phenomena or appearances) ; 

 that self-consciousness and the whole realm of the 

 inner world are distinct super - additions to the 

 primitive and primary functions of the nervous 

 system ; and that " innate ideas," as Locke proved in 

 1689, are non-existent. In other words, the facts 

 of nervous development consort with the agnostic 

 dogma of modern scientific philosophy, if I may 

 use this term to distinguish between the most gen- 

 eral conclusions of scientific thought and those 

 of the academic philosophers or metaphysicians. 



With this conclusion we may pass to the con- 

 sideration of superorganic evolution, and, in the 

 first place, the evolution of mind. 



