Most critics of the political evolution of Jean-Paul Sartre have laid emphasis on his allegedly sympathetic and uncritical attitude to Stalinist Communism due, to a large extent, to their equation of Marxism with Stalinism. It is true that Sartre was guilty of many serious misjudgements with regard to the USSR and the French Communist Party. But his relationship with the Marxist Left was much more complex and contradictory than most accounts admit. This book offers a political defence of Sartre and shows how, from a relatively apolitical stance in the 1930s, Sartre became increasingly involved in the politics of the Left; though he always distrusted Stalinism, he was sometimes driven to ally himself with it because of the force of its argument.