Jean-Paul Sartre

Jean-Paul Sartre (1905–1980) was a French philosopher, novelist, and playwright who transformed Martin Heidegger's phenomenology into the most systematic version of Existentialism ever articulated. In Being and Nothingness (1943), Sartre argued that consciousness is not a thing but a 'nothingness' — a perpetual negation of being-in-itself. The for-itself (consciousness) is defined by its freedom: it is what it is not, and not what it is. This is not merely a paradox but an ontological structure. Sartre's existentialism insists that existence precedes essence — humans are thrown into a universe without inherent meaning and must create themselves through choice. Yet Sartre's partner and intellectual interlocutor Simone de Beauvoir exposed the limits of this 'universal' subject: the supposedly free individual was historically male, and women's oppression was not merely political but ontological. Sartre's philosophy is the high-water mark of existentialist individualism — and the point at which its contradictions became visible.