8 EVOLUTION BY ATROPHY 



ing, from the point of view of evolution, between 

 biology and sociology, arises from the fact that the 

 evolution of societies as well as that of organisms, 

 is the result of the co-operation of two factors 

 similarity and adaptation. 



In biology, the similarity between organisms 

 springing from the same stock, is due to heredity, 

 while adaptation is the result of individual variation. 



In sociology, societies are the descendants of 

 former societies, in that the new are modelled 

 upon the old. Similarity is the result of imita- 

 tion, while adaptation is the result of invention 

 i.e. of all improvement and innovation tending 

 to make a new society different from that which 

 preceded it. 1 



These fundamental analogies suffice in themselves 

 to justify our collaboration, whatever may be the 

 solution of the question which is really only a 

 question of terms as to whether societies should 

 be regarded as organisms, or organisms as particular 

 kinds of societies. 2 



1 Invention is frequently a combination of several imitations. 

 When a society is formed, its characters are not necessarily 

 borrowed from those societies from which it more or less directly 

 proceeds. It may be modelled upon other social structures with 

 which it had no hereditary connection. V. Tarde, Les Lois de 

 limitation. 



2 See Les Socittes animates, p. 128 (Espinas). "Integration, 

 or grouping together, is a universal law common to all organic 

 or inorganic existence. 'Society, properly speaking, is only a 

 complex and important instance of this universal law." 



See La Science Sociale, p. 97 (Fouillee). " All purely physio- 



