Synchrony and diachrony

The concepts were theorized by the Swiss linguist Ferdinand de Saussure, professor of general linguistics in Geneva from 1896 to 1911, and appeared in writing in his posthumous Course in General Linguistics published in 1916. In contrast with most of his predecessors, who focused on historical evolution of languages, Saussure emphasized the primacy of synchronic analysis of languages to understand their inner functioning, though never forgetting the importance of complementary diachrony. This dualistic opposition has been carried over into philosophy and sociology, for instance by Roland Barthes and Jean-Paul Sartre. Jacques Lacan also used it for psychoanalysis. Prior to de Saussure, many similar concepts were also developed independently by Polish linguists Jan Baudouin de Courtenay and Mikołaj Kruszewski of the Kazan school, who used the terms statics and dynamics of language.