What is perhaps Louis Althusser's most famous text, "Ideology and Ideological State Apparatuses," published in 1970 and very influential ever since, was an extract of a much longer book published in French years after his death. Published now for the first time in English, "On the Reproduction of Capitalism" develops systematically Althusser's conception of historical materialism, outlining the conditions of reproduction in capitalist society and the revolutionary struggle for its overthrow. Written in the afterglow of May 1968, the text addresses a question that continues to haunt us today: in a society that proclaims its attachment to the ideals of liberty and equality, why do we witness the ever-renewed reproduction of relations of domination? Both an activist and a conceptually innovatory text, "On the Reproduction of Capitalism" is an essential addition to the corpus of the twentieth-century Left.