BIOLOGY, PSYCHOLOGY, AND SOCIOLOGY. 169 



guished by a segreg-ation of these social units into a few distinct classes. . . . 

 And without further illustration the reader will at once perceive, that from 

 these inferior types of society up to our own complicated and more perfect 

 one, the progress has ever been of the same nature." 



In pursuance of the analogy it is then shown that in either 

 case in proportion to the multiplication of unlike parts, severally 

 taking unlike functions, there is " an increasing mutual depend- 

 ence " and a consequent individuation (integration) of the whole 

 organism, animal or social : * the mutual dependence of parts being 

 represented as that which constitutes the aggregate an organism. 



Ten years later, in the essay on " The Social Organism," the 

 conception here briefly outlined was elaborated. Four analogies 

 between living bodies and bodies politic were enumerated. 



" Commencing as small aggregations, they insensibly augment in 

 mass. . . . While at first so simple in structure as to be considered struc- 

 tureless, they assume, in the course of their growth, a continually-increas- 

 ing complexity of structure. . . . Thoiigh in their early, undeveloped 

 states, there exists in them scarcely any mutual dependence of parts, their 

 parts gradually acquire a mutual dependence. . . . The life of a society is 

 independent of, aiid far more prolonged than, the lives of any of its com- 

 ponent units." {Essays, Library ed., vol. i, p. 272.) 



Neither in Social Statics, nor, I believe, in this essay is there 

 any assertion that this analogy between animal structures and 

 social structures is to be taken as the basis for sociological inter- 

 pretations. In what way the analogy has been regarded by me 

 was shown at a later date in The Study of Sociology. In that 

 work it is said : 



" Now if there exists this fundamental kinship, there can be no rational 

 apprehension of the truths of Sociology until there has been reached a 

 rational apprehension of the truths of Biology." (P. 334.) 



Taken by itself this sentence appears to justify the interpre- 

 tation given of my view, but the sentences immediately succeed- 

 ing show that this is not so. 



" The services of the two sciences are, indeed, reciprocal. We have but to 

 glance back at its progress, to see that Biology owes the cardinal idea on 

 which we have been dwelling, to Sociology; and that having derived from 

 Sociology this explanation of development, it gives it back to Sociology 

 greatly increased in definiteness, enriched by countless illustrations, and fit 

 for extension in new directions." 



In pursuance of this assertion it is pointed out that Milne-Edwards 

 derived " the conception of ' the physiological division of labor ' " 

 from the generalizations of political-economists. It is then said 

 that " when carried from Sociology to Biology, this conception 



* In passing I may remark that in the alleged progress from uniformity to multiformity, 

 as well as in the implied processes of differentiation and integration, may be seen the 

 earliest germ of the thought which eventually developed into the formula of evolution at 

 large. 



VOL. L. 15 



