8 INTRODUCTION 



Two other methods are suggested in Professor Carver's Sociol- 

 ogy and Social Progress. In the Introduction he analyzes 

 adaptation as passive and active material and passive and 

 active social. We might, then, trace the development of each 

 form of adaptation from Comte to the present. The difficulty 

 here is that several authors have made contributions bearing on 

 each of these four divisions, and such a method would make 

 impossible the study of the social theory of an author as a whole. 

 A third method might follow the outline in the book referred to, 

 and discuss the development of the doctrine from the side of 

 biology, economics, psychology and the social sciences including 

 religion. But our chief interest is to study social theories rather 

 than the writings of economists and social scientists except as 

 they bear directly on the subject in hand, and here, again, as in 

 the previous case, some authors have contributed along several 

 different lines. 



It seems best, therefore, to discuss the social theories of the 

 writers who have been most influential in the development of this 

 doctrine of adaptation or whose contributions are most important 

 in a constructive social philosophy built around this concept, and 

 in an order which shall be, so far as possible, both historical and 

 logical. In the treatment of some writers attention will be given 

 only to their specific contribution to our subject while in the case 

 of others a brief outline of their general social philosophy will be 

 necessary as a background for a due appreciation of that contri- 

 bution. The work as a whole will thus furnish an approach to a 

 constructive social philosophy by a review of the systems of many 

 writers not only in English but also in German and French. 



Definition of Terms. Adaption may be considered as a state 



or as a. nrnress. 1 By the former is meant such relationship be- 



. . ... 



tween an organism, species, social group or institution as is 



favorable to existence aiid ^iuwlh, b.y Lhl! lulled is meant the 

 process by which such a unity becomes and continues in favorable 

 relation to its environment. There are two general classes of 

 environment, physical or material, and spiritual, including social, 

 and two general classes of adaptation, passive and active. By 



1 Cf. Haeckel, The Last Link, pp. 84, 117 f. 



