ILLUSTRATIONS AND CRITICISMS 



neity is determined by the continuous increase 

 of heterogeneity in the environment. 



Fourthly^ we saw that the increase of hetero- 

 geneity in the environment is determined by the 

 successive integratipn of communities into more 

 and more complex and coherent aggregates. 

 And this law alsoHolds of organic progress. 



These four generalizations, expressing the 

 points in which social and organic development 

 coincide, were summed up in the first two 

 clauses of our law of progress. They are imme- 

 diate corollaries of the law of universal evolution 

 and of the definition of life as adjustment. They 

 are not to be understood as mere expressions of 

 striking analogies. They are to be understood 

 as implying that the evolution of life and the 

 evolution of society are, to a certain extent and 

 in the most abstract sense, identical processes. 

 Such a conclusion, indeed, became inevitable the 

 moment we were brought to admit that the phe- 

 nomena of society constitute but a specialized 

 division of the phenomena of psychical life. 



Nevertheless it would be a grave error to in- 

 fer, from this necessary coincidence in develop- 

 ment, that a community is nothing more than 

 a kind of organism, as Plato imagined in his 

 " Republic," and Hobbes in his " Leviathan." 

 When we go so far as to compare the metrop- 

 olis of a community to the heart of an organ- 

 ism, its roads to blood vessels, its circulating 



