Stimulation for this study, first published in 1981, came from working on the translation and introduction to Simmel's "The Philosophy of Money" (Routledge 1978; new edition 1990). It was intended as a provocative introduction to some aspects of Simmel's social theory. It challenged many earlier conceptions of Simmel's work, most notably the view that Simmel produced a "formal" sociology. It also drew out the significance of the aesthetic dimension in Simmel's work. A major feature of the study, presented here in its first paperback edition, is that it locates Simmel within the social and intellectual "milieu" in which he was working, by drawing upon many little known essays and pieces by Simmel and his contemporaries. A new afterword takes up new material on Simmel's aesthetic stance and confronts critical responses to the first edition of the book. Providing a critical introduction to Simmel's social theory, it should be of interest to students of sociology, philosophy, and German studies.