THE STUDY OF SOCIOLOGY. 601 



ment and organization, to the direct influences it exerts by furnishing 

 an adequate theory of the social unit Man. For, while Biology is 

 mediately connected with Sociology by a certain parallelism between 

 the groups of phenomena they deal with, it is immediately connected 

 with Sociology by having within its limits this creature whose proper- 

 ties originate social evolution. The human being is at once the termi- 

 nal problem of Biology and the initial factor of Sociology. 



If Man were uniform and unchangeable, so that those attributes 

 of him which lead to social phenomena could be learned and dealt 

 with as constant, it would not much concern the sociologist to make 

 himself master of other biological truths than those cardinal ones 

 above dwelt upon. But, since, in common with every other creature, 

 Man is modifiable since his modifications, like those of every other 

 creature, are ultimately determined by surrounding conditions and 

 since surrounding conditions are in part constituted by social arrange- 

 ments it becomes requisite that the sociologist should acquaint him- 

 self with the laws of modification to which organized beings in gen- 

 eral conform. Unless he does this he must continually err, both in 

 thought and deed. As thinker, he will fail to understand the con- 

 tinual action and reaction of institutions and character, each slowly 

 modifying the other through successive generations. As actor, his 

 furtherance of this or that public policy, being unguided by a true 

 theory of the effects wrought on citizens, will probably be mischievous 

 rather than beneficial ; since there are more ways of going wrong than 

 of going right, How needful is enlightenment on this point will be 

 seen, on remembering that scarcely anywhere is attention given to 

 the modifications which a new agency, political or other, will produce 

 in men's natures. Immediate influence on actions is alone contem- 

 plated, and the immeasurably more important influence on the bodies 

 and minds of future generations is wholly ignored. 



Yet the biological truths which should check this random political 

 speculation and rash political action are conspicuous, and might, one 

 would have thought, have been recognized by every one, even without 

 special preparation in Biology. That faculties and powers of all orders, 

 while they grow by exercise, dwindle when not used, and that altera- 

 tions of nature descend to posterity, are facts continually thrust on 

 men's attention, and more or less admitted by all. Though the evi- 

 dence of heredity, when looked at in detail, seems obscure, because 

 of the multitudinous differences of parents and of ancestors, which all 

 take their varying shares in each new product, yet, when looked at 

 in the mass, the evidence is overwhelming. Not to dwell on the 

 countless proofs furnished by domesticated animals of many kinds as 

 modified by breeders, the proofs furnished by the human races them- 

 selves are amply sufficient. That each variety of man goes on so re- 

 producing itself that adjacent generations are nearly alike, however 

 appreciable may sometimes be the divergence in a long series of gen- 



