Another important result of our study of the terminology of relationship is that it helps us to understand the proper place of psychological explanation in sociology. These lectures have largely been devoted to the demonstration of the failure to explain features of the terminology of relationship on psychological grounds. If this demonstration has been successful, it is not because the terminology of relationship is anything peculiar, differing from other bodies of sociological facts; it is because in relationship we have to do with definite and clean-cut facts. The terminology of relationship is only a specially favourable example by means of which to show the value of an attitude towards, and mode of treatment of, social facts which hold good, though less conspicuously, throughout the whole field of sociology. In social, as in all other kinds of human activity, psychological factors must have an essential part. I have myself in these lectures pointed to psychological considerations as elements in the problems with which the sociologist has to deal. These psychological elements are, however, only concomitants of social processes with which it is possible to deal apart from their psychological aspect. It has been the task of these lectures to refer the social facts of relationship to antecedent social conditions, and I believe that this is the proper method of sociology. Even at the present time, however, it is possible to support sociological arguments by means of considerations provided by psychological motives, and the assistance thus rendered to sociology will become far greater as the science of social psychology advances. This is, however, a process very different from the interpolation of psychological facts as links in the chain of causation connecting social antecedents with social consequences. It is in no spirit of hostility to social psychology, but in the hope that it may help us to understand its proper place in the study of social institutions that I venture to put forward the method followed in these lectures as one proper to the science of sociology.[37] [37] See also “Survival in Sociology,” _Sociological Review_, 1913, vol. vi., p. 293. I hope shortly to deal more fully with the relations between sociology and social psychology.