Sociologist and philosopher, born in Berlin. He studied at Berlin University, where he became a lecturer in 1885, teaching philosophy and ethics, and in 1900 was appointed professor of the new discipline of sociology. In 1914 he moved to a chair in philosophy at Strasbourg, where he remained until his death. Instrumental in establishing sociology as a social science, he also wrote extensively on philosophy in such works as Philosophie des Geldes (1900, Philosophy of Money).