"Of those who created the intellectual capital used to launch the enterprise of professional sociology, Georg Simmel was perhaps the most original and fecund. In search of a subject matter for sociology that would distinguish it from all other social sciences and humanistic disciplines, he charted a new field for discovery and proceeded to explore a world of novel topics in works that have guided and anticipated the thinking of generations of sociologists. Such distinctive concepts of contemporary sociology as social distance, marginality, urbanism as a way of life, role-playing, social behavior as exchange, conflict as an integrating process, dyadic encounter, circular interaction, reference groups as perspectives, and sociological ambivalence embody ideas which Simmel adumbrated more than six decades ago."?Donald N. LevineHalf of the material included in this edition of Simmel's writings represents new translations. This includes Simmel's important, lengthy, and previously untranslated "Group Expansion and Development of Individuality," as well as three selections from his most neglected work, Philosophy of Money; in addition, the introduction to Probleme der Geschichtsphilosophie, chapter one of the Lebensanschauung, and three essays are translated for the first time.