There have been three decided trends in sociological investigation in recent years, the statistical, social psychological, and historical. This essay is concerned with the latter. The history that sociology utilizes is the "new history." Among the uses which sociology has made of history are the following: the ability to interpret the present, the substantiation of social evolution, the proof of the rality of social change, the perception of cause and effect in social phenomena, its substitution for impossible experimentation, the recognition of the fact that all social effort must take recent trends into consideration, the use of trends and tendencies to anticipate future effects, the conclusion that progress must come by telic activity, as a guide in the determination of the antecedents and consequences of social revolutions, and the provision of knowledge useful in curing or preventing them, the presentation of social psychological data, and facts concerning the development, role, and decadence of inst...