These skillfully written essays are based on the Georg Simmel Lectures delivered by Neil J. Smelser at Humboldt University in Berlin in the spring of 1995. A distillation of Smelser's reflections after nearly four decades of research, teaching, and thought in the field of sociology, the essays identify, as he says in the first chapter, ". . . some central problematics--those generic, recurrent, never resolved and never completely resolvable issues--that...