Contrary to other key elements of Luhmann’s systems theoretical sociology, his theory of functional differentiation has not been widely received among historians of modern society. The article is discussing some reasons for this situation. One important reason is the persistence of an older, Parsonian concept of differentiation along the lines of a stable three- or four-tier model. Another one is the assumption held by many social historians, particularly since the boom of cultural history in the 1980s, that the economy has to be seen as a core of modern society, and that modern society can hence be best described as a ‘class society’. The paper also discusses the use of Luhmann’s theory of functional differentiation in the social history of religion, where its has been employed to conceptualise secularisation as a reversible process in which the Catholic Church tried to adapt to functional differentiation and react in its pastoral strategies to some of its social consequences
