Organic Connection Between Physical and Psychical 245 



here) there is no course open but to recognize that the or- 

 ganism is a very important, because indis})ensable, factor in 

 its own growth and differentiation. "Self differentiation," 

 so far as the whole organism is concerned, is a fact than 

 which no other in the whole domain of biology is better es- 

 tablished. Indeed, self differentiation is really a special 

 form of self growth and surely no one would contend that 

 environmental influence is more than an essential factor in 

 the growth of an organism. To hold it to be a complete 

 explanation of the phenomenon would be too manifestly ab- 

 surd to receive serious consideration. It would be to con- 

 tend, in effect, that one of the processes of the organism 

 (its growth) is more than all the processes of the whole or- 

 ganism. But since most if not all variation depends, either 

 directly or indirectly, upon growth, what is more natural 

 than that the living, growing organism should display much 

 self variation.^ 



That such variations are among the most common phe- 

 nomena presented by organic beings, there is no shadow of 

 doubt to any one who views the problem broadly and crit- 

 ically, and with no domineering preconceptions as to what 

 ought to be and ought not to be ; who, in other words, views 

 the organic world as a natural historian, guided by the 

 mandate "neglect nothing," instead of as a physicist in the 

 mathematico-laboratory sense, guided by the mandate "neg- 

 lect everything which can not be made to conform to gen- 

 eral mathematically statable law." 



These remarks about the relation of mental activity to 

 growth, differentiation and variation of the organism, and 

 to environmental Influence would apply throughout, muta- 

 tis mutandis, to troplstic activity. 



