Being and Nothingness

Being and Nothingness: An Essay on Phenomenological Ontology (French:L'Être et le néant : Essai d'ontologie phénoménologique), sometimes subtitled A Phenomenological Essay on Ontology, is a 1943 book by philosopher Jean-Paul Sartre. Sartre's main purpose is to assert the individual's existence as prior to the individual's essence ("existence precedes essence"). His overriding concern in writing the book was to demonstrate that free will exists. While a prisoner of war in 1940 and 1941, Sartre read Martin Heidegger's Being and Time, an ontological investigation through the lens and method of Husserlian phenomenology (Edmund Husserl was Heidegger's teacher). Reading Being and Time initiated Sartre's own philosophical enquiry.