1 56 THE AMERICAN JOURNAL OF SOCIOLOGY
states the main thesis of the school to be that nature determines work and reward, which in turn mold the society and differentiate its population. 43 Demolins in recent volumes has illustrated the Le Play theories concretely as applied to the creation of different local types in France, and as explaining the leading racial groups of the world. 44 A similar tendency is observable in the United States, where scientists like Shaler and Brigham, historians like Hart and Turner, geographers like Ripley and Miss Semple, and sociologists like Giddings, have been at work upon the problem of environmental influence. The general tendency away from the idea of immediate effects toward the theories of influence exerted indirectly through social institutions is attributable largely to the increasingly important part which sociology is playing, not only as a science, but as a social philosophy which affects all the social sciences.
The idea of social progress was fundamental with all the philosophers of history. Whether spiral as with Vico, or recti- linear as with Condorcet, the path of human advancement was not to be missed. DeGreef has traced the historical origin and development of this idea which was a part of the heritage of the nineteenth century from the past. 45 Rousseau's " back to nature " and the golden age of primitive innocence left this optimistic dream intact. Comte by his division of sociology into static and dynamic provided a new term for progress which he regarded as conditioned by the intellectual movement generalized in the law of the three stages. With the prevalence of positivism all differ- ences of opinion "intellectual anarchy" would perforce dis- appear and complete harmony would reign in a final static order. The idea of evolution as illustrated by social changes is the great central concept of nineteenth-century sociology. It is everywhere dominant, and every problem has been stated or restated in terms of the developmental doctrine. But evolution and progress are
- VICNES, La science sociale, d'aprts les principes de Le Play (Paris, 1897),
PP. 57-63.
44 DEMOLINS, Lcs Frangais d'aujourd'hui (Paris, 1898); Comment la route cree le type social (Paris, 1901).
- DEGREEF, Le transformisme social (Paris, 1893).
