in the first two chapters: (1) It is essential to distinguish between various modes of collective life,—(a) "the instinctive or gregarious group" which is biologically determined and is based on inherited tendencies, (b) "the spontaneous or plastic group" which is determined by feeling and impulse and is based on social heredity, on learning and imitation, and (c) "the reflective or social group proper" which is determined by intelligence and is based on reasoned motives and ideals. Only this last form of organization is social in the true sense of the word. "Every social situation is constituted by the thinking and acting of certain individuals, in varying degrees and sorts of co-operation or opposition constituting the socal relationship" (p. 29). The key for the interpretation of social phenomena, therefore, must in every case be found not in biology but in psychology. (2) The sociological unit is not the 'single person' but the 'socius'; "the social relation is in all cases intrinsic to the life, interests, and purposes of the individual" (p. 28). The normal development of the individual, therefore, inevitably brings him into essential solidarity with his fellows. In reply to the question, what in that case still remains true of individualism, Chapter III, "Competition and Individualism," tells us that "growing solidarity results in a cessation or diminution of individualism" (p. 82),—a careless statement of the fact, more accurately expressed in other chapters, that with growing solidarity mere individualism, in the sense of an atomistic self-reference inevitably wanes. Not only does the intensity of the biological struggle for existence diminish, but its point of incidence is shifted. "It is now a struggle between groups, not one between individuals" (p. 83); "the organized whole faces the competition with other wholes of interest or utility" (p. 115). The discussions in Chapters IV and VI concerning the principles that underlie the social institutions of school, state, and church, and those involved in business organization, aim to illustrate the fact that the traditional contrast between individual and social interest is artificial and mistaken. Collectivist theory must not be carried to the extreme, as it is, for example, in the case of Socialism; nor must individualistic doctrine, as it is, for example, in such theories of religion as that of Professor James, in which the unique personal and subjective aspect is overemphasized and the fact is disregarded that "the religious experience is normally developed within the control of social and moral motives," and that "the religious spirit seeks social embodiment and normally finds it" (p. 142). Believing, then, that the motive to individualism is not entirely subverted, the author devotes a chapter, "Social Invention and Progress," in pointing out how it enters into that continuous and coherent social movement called progress. Natural selection cannot secure progress but only "preserve and extend the group in which a social type is present"; "the type that is worth selecting and extending arises within the group by processes of internal organization" (p. 148). Social progress depends upon the psychological factor of invention, upon the fact that man has imagination as well as perception, thought as well as mere recognition, ideals as well as sentiment for the actual. All advance in knowledge and in science, as the Genetic Logic has shown us in such careful detail,
