IV. 

 The Origin of Infancy. 



UT before we can fully understand 

 the exalted position which the 

 Darwinian theory assigns to man, 

 another point demands consideration. The 

 natural selection of psychical peculiarities 

 does not alone account for the origin of 

 Man, or explain his most signal difference 

 from all other animals. That difference is 

 unquestionably a difference in kind, but in 

 saying this one must guard against mis- 

 understanding. Not only in the world of 

 organic life, but throughout the known 

 universe, the doctrine of evolution regards 

 differences in kind as due to the gradual 

 accumulation of differences in degree. To 

 cite a very simple case, what differences of 

 kind can be more striking than the differ- 

 ences between a nebula, a sun, a planet 



