BIOLOGY AND SOCIOLOGY 77 



nomena received in some degree an explanation if 

 their origin from simpler phenomena could be dem- 

 onstrated. As a matter of fact, reflection makes it 

 clear that such an explanation is never complete. It 

 is a very incomplete explanation of the properties 

 of water to discover that it is composed of oxygen 

 and hydrogen; or of those of humanity to discover 

 that it is derived from lower forms of life. A pre- 

 cisely similar mistake is made by most psycho- 

 analysts, who consider that an "explanation" of 

 adult psychology is given by tracing in it effects of 

 the events of childhood. In all such cases it is true 

 that analysis is helped, but we are by no means 

 exempted from further study of the later (and more 

 complex) phenomena in and for themselves. Just 

 as adult psychology is qualitatively different in va- 

 rious respects from childish psychology, so is man 

 qualitatively different from lower organisms. Very 

 few attempts have been made to carry over concep- 

 tions derived from sociology into biology.^ But the 

 converse, as we have seen, has often been true, and 

 numerous writers — largely because purely biological 

 are simpler than human phenomena — have been 

 obsessed with the idea that the study of biology as 

 such will teach us principles which can be applied 

 directly and wholesale to human problems. 



What we have just been saying shows us the cor- 

 rect path. Through psychology and biology, soci- 



2 Morley Roberts is a recent exception. See his interesting 

 book, Warfare in the Human Body. 



