Jean-Paul Charles Aymard Sartre (/ˈsɑːrtrə/, US also /ˈsɑːrt/; French: [saʁtʁ]; 21 June – 15 April ) was a French philosopher, playwright, novelist, screenwriter, political activist, biographer, and literary critic, considered a leading figure in 20th-century French philosophy and Marxism. Sartre was one of the key figures in the philosophy of existentialism (and.