I. I NTRODUCTION
Few subjects have led to discussion so animated and prolonged as has the definition of the science of sociology. It is therefore necessary, as it is hoped that this essay may be capable of sociological applications, that the writer should define the sense in which he uses the term. By calling it a science is, of course, denoted the view that sociology is a body of knowledge derived from experience of its material and co-ordinated so that it shall be useful in forecasting and, if possible, directing the future behaviour of that material. This material is man in society of associated man.
Sociology, therefore, is obviously but another name for psychology, in the widest sense, for, that is to say, a psychology which can include all the phenomena of the mind without the exception even of the most complex, and is essentially practical in a fuller sense than any orthodox psychology which has yet appeared.
Sociology has, of course, often been described as social psychology and has been regarded as differing from ordinary psychology in being {12} concerned with those forms of mental activity which man displays in his social relations, the assumption being made that society brings to light a special series of mental aptitudes with which ordinary psychology,