472 THE CAUSES OF THE xi 



brain do not exist at all and you teach that all 

 functions, intellectual, moral, and others, are the 

 expression or the result, in the long run, of struc- 

 tures, and of the molecular forces which they 

 exert." It is quite true that I do so. 



" Well, but," I am told at once, somewhat 

 triumphantly, " you say in the same breath that 

 there is a great moral and intellectual chasm 

 between man and the lower animals. How is 

 this possible when you declare that moral and in- 

 tellectual characteristics depend on structure, and 

 yet tell us that there is no such gulf between the 

 structure of man and that of the lower animals ? " 



I think that objection is based upon a miscon- 

 ception of the real relations which exist between 

 structure and function, between mechanism and 

 work. Function is the expression of molecular 

 forces and arrangements no doubt; but, does it 

 follow from this, that variation in function so 

 depends upon variation in structure that the former 

 is always exactly proportioned to the latter ? If 

 there is no such relation, if the variation in func- 

 tion which follows on a variation in structure may 

 be enormously greater than the variation of the 

 structure, then, you see, the objection falls to the 

 ground. 



Take a couple of watches made by the same 

 maker, and as completely alike as possible ; set 

 them upon the table, and the function of each 

 which is its rate of going will be performed in 



