Louis Althusser.On Marx and Freud. RM 4(1):17-30 The points of convergence and departure in the theories of Karl Marx and Sigmund Freud are discussed. Both established ³conflictual theories,² sciences that have been defined by strong resistance, revisions, and schisms, as a result of the challenges they presented to crucial aspects of bourgeois social theory: Marx with his notion of class exploitation and Freud by his idea of a unified psyche in which all subjective components are subjugated to consciousness and reason. Several key differences between the two are identified, especially Freud's discovery of the decentered individual. It is concluded that an understanding of their discoveries is necessary to wage class struggle on behalf of the proletariat in the realms of theoretical and political practice.