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narrow life-purpose unfulfilled and exposes this to infractions. Social relationships, hence social structures, are a consequence of our biological evolution, of the primitive force working therein, and of differentiating individuation. Self-preservation, physiological inter- est, the effort to perfect our individual and social interest, the effort to propagate our racial interests, force us to social relation- ships. Thus we can impute to social evolution as a more remote effect of causes active in the evolution of the creature no other laws than those which are peculiar to biological occurrences — just as the laws of chemistry, physics, mechanics, geology, and, lastly, cosmology were fundamentally established by recourse to earlier evolutionary pro- cesses. So the unity of law in the world spontaneously presents itself. The difficulty in discerning this unity disappears before a knowledge of the decisive significance of inherent ' interest ' for all individua- tion of primitive force. Just as, in the order of evolution of conscious creatures, we observe a growth of the faculties of consciousness whereby the individual seeks more and more to guard his interest through extensive thought-combinations, so the changes accompanying social phenomena grow more and more out of the immediate realm of physio- logical interest, and gain a psychical content. But in this connection we may not forget that this content has the nucleus of its being always in that physiological interest. The lower the organism stands, the simpler is the dependence of the social structure to which it belongs upon the material concerns of the species. The social structures of the plant world are but the product of its propagating increase ; those of the animal world are a product of this increase, and also a product of natural selection, of union for predatory purposes, and for protec- tion against other species. For men also the same motives for social union originally existed ; but with increasing civilization the mediate gratification of wants becomes the motive for social union, whose coherence with the material interest of the individual or the species can be recognized only through combinations of ideas. Through elevation of the social world into the world of psychical relationships the validity of biological laws is not, on that account, annulled, because everything psychical has its roots in the reality of facts and phenomena. We must only know how to apprehend these biological conditions intelligently. The nearer the motive to a social union stands to physiological interest, the less easily can a societary element withdraw from its association ; it will arise and perish in its association like the cell in the organism. This is met with in most associations based
