the tracing of these analogies is not the essence of sociology, but merely the most vivid method of presenting the phenomena of society in such form that the actual problems of sociology will appear. The analogies and terms suggested by them are tools of research and report, not solutions of problems…. The metaphors emphasize obvious analogies between social relations and physiological relations. They are used as spurs to scientific curiosity, so as to facilitate discovery of the limits of analogy, and thus of the distinctively social phenomena (Small 1896: 311).