Jacques-Marie-Émile Lacan (April 13, 1901 – September 9, 1981) was a French psychoanalyst and psychiatrist.
His work, like most psychoanalytic work, owes a heavy, explicit debt to Sigmund Freud, but also drew from a number of other fields, including linguistics, philosophy, and mathematics.
This interdisciplinary focus in his work has led him to be an important figure in many fields beyond psychoanalysis - particularly within critical theory.
His central idea was that the human subject is a creation of its use of language. From this understanding Lacan develops his study of psychoanalysis and his treatment strategies. His work, while controversial, continues to influence the development of psychoanalysis worldwide. In France and elsewhere various "schools" of Lacanian thought have emerged.