12 Social progress implies heredity 



food and possibly no clothing, who possessed 

 only the rudest implements and had but a 

 cave for his dwelling — the interval, I say, 

 between him and civilised man with his long 

 traditions, fixed laws, innumerable arts and 

 organised division of labour, sufficiently 

 illustrates the character of this progress 

 when already far advanced. The inheritance 

 of the permanent achievements of one gen- 

 eration by the next is obviously the main 

 factor of such social progress : this we may 

 call heredity in the literal sense. But we talk 

 also of heredity as a factor in the biological 

 progress from the Protista up to Man; 

 though here the heir and the inheritance can 

 only be distinguished by calling the individual 

 the heir and his organism the inheritance, 

 that is to say by regarding as two what the 

 biologist conceives as one. It is this bio- 

 logical heredity that is our problem. 



