Lacan’s life spanned almost the entire twentieth century. He was acquainted with almost all the major figures of European philosophy during this time, including Jean-Paul Sartre, Simone de Beauvoir, Martin Heidegger, and Jacques Derrida. He lived an intellectual life and profited from these philosophical interlocutors to develop his own thought. Typically, Lacan borrowed from other philosophers, but they did not avow any direct influence from him. The one exception is the Marxist Louis Althusser, who helped to find a home for Lacan’s seminar when he lost his previous site and who integrated Lacan’s thought into his Marxism. Lacan’s philosophy constantly changed throughout his life as he responded to new exigencies and to the developments of other thinkers.