Michel Pêcheux particularly specialized on 'discourse analysis' and epistemological problems in that field. The jargon term 'discourse' can simply be translated by 'text' or something like that, with this distinction that, within discourse, language and society are bound up inextricably, whereas a text is often seen as something purely linguistic. This article is an introduction to Pêcheux's Language, Semantics and Ideology (Les vérités de La Palice), in which he develops his interpretation of the concept of discourse. By closely connecting language and society within his object of research Pêcheux undertakes to defend a hardly recognized frontier zone between text analysis (linguistics) on the one hand and social theory (which he borrows from Marxism) on the other.