In accordance with Husserl's notion that consciousness can only exist as consciousness of something, Sartre develops the idea that there can be no form of self that is 'hidden' inside consciousness. Born into the material reality of one's body, in a material universe, one finds oneself inserted into being. In Sartre's account, man is a creature haunted by a vision of 'completion' (what Sartre calls the ens causa sui, meaning literally 'a being that causes itself'), which many religions and philosophers identify as God. Though influenced by Heidegger, Sartre was profoundly skeptical of any measure by which humanity could achieve a kind of personal state of fulfillment comparable to the hypothetical Heideggerian 're-encounter with Being'. Sartre attributed the course of his own philosophical inquiries to his exposure to this work. While a prisoner of war in 19, Sartre read Martin Heidegger's Being and Time (1927), which uses the method of Husserlian phenomenology as a lens for examining ontology. In the book, Sartre develops a philosophical account in support of his existentialism, dealing with topics such as consciousness, perception, social philosophy, self-deception, the existence of 'nothingness', psychoanalysis, and the question of free will.

Being and Nothingness: An Essay on Phenomenological Ontology ( French: L'Être et le néant : Essai d'ontologie phénoménologique), sometimes published with the subtitle A Phenomenological Essay on Ontology, is a 1943 book by the philosopher Jean-Paul Sartre.

Being and nothingness hazel barnes