Georg Simmel's highly original take on the newly revived field of sociology succeeded in making the field far more sophisticated than it had been beforehand. He took insights from dialectical thought and Kantian epistemology to develop a 'form sociology' method that remains implicit in the field a century later. Forms include such patterns of interaction as inequality, secrecy, membership in multiple groups, organization size, and coalition formation. While today texts and professional societies are organized around 'contents' rather than 'forms', a fresh reading of Simmel's chapters on forms...