600 THE POPULAR SCIENCE MONTHLY. 



nates from the generalization previously reached in Political Econ- 

 omy. Recognition of the advantages gained by a society when differ- 

 ent groups of its members devote themselves to different industries, 

 for which they acquire special aptitudes and surround themselves with 

 special facilities, led to recognition of the advantages which an indi- 

 vidual organism gains when parts of it, originally alike and having 

 like activities, divide these activities among them; so that each, taking a 

 special kind of activity, acquires a special fitness for it. But now note 

 that, when carried from Sociology to Biology, this conception was forth- 

 with greatly expanded. Instead of being limited to the functions in- 

 cluded in nutrition, it was found applicable to all functions whatever. 

 It turned out that the arrangements of the entire organism, and not 

 of the viscera alone, conform to this fundamental principle even the 

 differences arising among the limbs, originally alike, were soon to be 

 interpret able by it. And then mark that the idea, thus developed 

 into an all-embracing truth in Biology, comes back to Sociology ready 

 to be for it, too, an all-embracing truth. For it now becomes mani- 

 fest that not to industrial arrangements only does the principle of the 

 division of labor apply, but to social arrangements in general. The 

 progress of organization, from that first step by which there arose a 

 controlling chief, partially distinguished by his actions from those 

 controlled, has been everywhere the same. Be it in the growth of a 

 regulative class more or less marked off from classes regulated be it 

 in the partings of this regulative class into political, ecclesiastical, 

 etc. be it in those distinctions of duties within each class which are 

 signified by gradations of rank we may trace everywhere that fun- 

 damental law shown us by industrial organization. And, when we 

 have once adequately grasped this truth which Biology borrows from 

 Sociology and returns with vast interest, the aggregate of phenomena 

 which a society at any moment presents, as well as the series of devel- 

 opmental changes through which it has risen to them, become suddenly 

 illuminated, and the rationale comparatively clear. 



After a recognition of this fundamental kinship there can be no 

 difficulty in seeing how important, as an introduction to the study of 

 social life, is a familiarization with the truths of individual life. For 

 individual life, while showing us this division of labor, this exchange 

 of services, in many and varied ways, shows it in ways easily traced ; 

 because the structures and functions are presented in directly-per- 

 ceivable forms. And only when multitudinous biological examples 

 have stamped on the mind the conception of a growing interdepend- 

 ence that goes along with a growing specialization, and have thus in- 

 duced a habit of thought, will its sociological applications be duly 

 appreciated. 



Turn we now from the indirect influence which Biology exerts on 

 Sociology, by supplying it with rational conceptions of social develop- 



