42 The Directio7t of Evolution 



The recognition of the essentially psychophysical na- 

 ture of the evolution process becomes increasingly im- 

 perative in the light of such a setting together of the 

 subordinate problems in a single whole. We find as we 

 advance a gradual shifting of the emphasis from the phys- 

 ical to the mental. This is not only true in respect to 

 the sort of utilities which ' fit ' variations subserve, but also 

 in the very means of transmission itself. It is pointed out 

 in the earlier work on Social and Ethical Interpretations 

 that, as tradition advances, and with it a corresponding in- 

 crease in the plasticity of the young v/ho are educated in 

 this tradition, social transmission comes directly to super- 

 sede the physical transmission of particular functions. 

 Social transmission, however, is a process quite distinct 

 from physical heredity. It has laws of its own.^ The dif- 

 ference is so great that I have ventured to characterize 

 social transmission as, in a sense, the means of the eman- 

 cipation of mind from the limitations of biological prog- 

 ress ; for by it there is secured a means of propagation 

 of intelligent conduct without the negativing, swamping, 

 and regressive effects of physical reproduction. ^'Trans- 

 mission by handing down, with imitative learning, is so 

 different from transmission by physical heredity, that the 

 series of conceptions which in the lower stages of evolu- 

 tion hold for both body and mind together — where both 

 are subject to the single law of congenital variation with 

 natural selection -^ are no longer common to them, but 

 a series of additional conceptions emerge which are com- 

 parative principles principally in name. There are such 

 differences in their operation in the two spheres respectively 



1 An attempt to work out certain of these laws is made in Chap. II. of the 

 work just cited. 



