Professor Ludwig Gumplowicz [1883] has tried to demonstrate that the true elementary social phenomena are the conflicts, amalgamations, and assimilations of heterogeneous ethnical groups. M. Novicow [1893], generalising further, argues that social evolution is essentially a progressive modification of conflict by alliance, in the course of which conflict itself is transformed from a physical into an intellectual struggle. Professor De Greef [1886], looking at the question in a very different way, finds the distinctive social fact in contract, and measures social progress according to the displacement of coercive authority by conscious argument. Mr. Gabriel Tarde [1890], in an original and fascinating study, which has made an enduring impress on both psychological and sociological thought, argues that the primordial social fact is imitation, a phenomenon antecedent to all mutual aid, division of labour, and contract. Professor Émile Durkheim [1895], dissenting from the conclusions of M. Tarde, undertakes to prove that the characteristically social process, and therefore the ultimate social phenomenon, is a coercion of every individual mind by modes of action, thought, and feeling that are external to itself (p. 14). According to Giddings, the original and elementary subjective fact in society is “the consciousness of kind.” Social psychology offers a vast and fertile field which has been but little worked, and there was needed an introduction to the subject which should afford that general point of view which is the starting-point of further studies. This Dr. W. McDougall has attempted in a recently published little book.[108] His general conclusion is that the life of societies is not merely the sum of the activities of individuals moved by enlightened self-interest, or by intelligent desire for pleasure and aversion from pain; but that the springs of all the complex activities that make up the life of societies must be sought in the instincts and in the other primary tendencies that are common to all men and are deeply rooted in the remote ancestry of the race. Professor E. A. Ross, of Wisconsin, simultaneously attacked the same subject, on the problems of which he had previously written.[109] [Sidenote: =Magic and Religion.=]