Under the influence of Edmund Husserl and, more importantly, Martin Heidegger, Sartre developed his existentialism as an analysis of self-consciousness in relation to Being. In the 1930s he wrote several phenomenological analyses of the imagination and the emotions, which culminated in his most important philosophical work, Being And Nothingness (1943; Eng. trans., 1956). This book provided a brilliant philosophical structure for the inchoate feelings of dissatisfaction that swept postwar Europe. The book's central idea is the opposition between objective things and human consciousness, the latter being a non-thing insofar as its reality consists in standing back from things and taking a point of view on them. Because consciousness is a non-thing (which is a somewhat better translation of Sartre's "neant" than the literal translation, "nothingness"), it does not have any of the causal involvements that things have with other things. This means that consciousness and thus humans themselves are essentially free, and that any attempt by an individual person or a philosophical theory to believe otherwise is a form of self-deception, or "bad faith."Ironically, the freedom of human consciousness is experienced by humans as a burden ("Man is condemned to be free"). Human projects, therefore, consist in the impossible attempt to become a free consciousness, such as when a person tries to become an intellectual or a parent or to play any other determinate social role. Because the impossibility of this attempt to become a conscious thing--in Sartre's terminology, a for-itself-in-itself--does not prevent humans from being irresistibly drawn to undertake it, Sartre declares that "man is a useless passion." Whether this entails that all human life is futile and without value, however, is another issue, and the vigor of Sartre's own life suggests that he himself did not draw this conclusion. Another debatable issue is whether there is any significant continuity between Sartre's existentialism and his later Marxist work, The Critique of Dialectical Reason (1960), a difficult analysis of social existence in which he attempts to explain how the freedom of the individual is related to history and the class struggle.
