Ernst Troeltsch was a liberal German Protestant theologian and philosopher of religion whose work spans the last decades of the German Empire and the early Weimar Republic. He studied theology at the Universities of Erlangen, Berlin, and Göttingen before becoming a professor of theology at Heidelberg (1894), followed by an appointment in the Philosophy Department at the University of Berlin (1915–23). His most famous work is Die Soziallehren der christlichen Kirchen und Gruppen (1912; The Social Teachings of the Christian Churches), which outlines a methodological approach to understanding the basic social and ethical teachings of European Christianity from the first to the eighteenth century.