Andrew Dobson charts Sartre's transformation from novelist and apolitical philosopher of existentialism, before the Second World War, to a committed defender of Marxism and Marxist method after it. Examining Sartre's post-war work in detail, he shows how the biographies of Baudelaire, Genet and Flaubert, often considered tangential to his main oeuvres, are in fact central to this defence of Marxism, and should therefore be read as acts of political commitment. Andrew Dobson's study of posthumous sources, including the extended commentaries in English of Volume II of the Critique of dialectical reason, and in its insistence on reading Sartre's philosophical development as primarily politically motivated. It provides a clear reading of some of Sartre's less familiar works, situating them in an overarching social and political project.