Born in 1905, Jean-Paul Sartre was one of the most influential philosophers of the twentieth century. He believed that philosophical arguments were most persuasive when presented as fiction. However, unlike works such as Voltaire's Candide, Sartre's fiction rejected the allegory and parable genres, and instead plainly outlined many of his most complicated ideas in a thinly veiled narrative format. Although Sartre is most well known for his straightforward philosophical analysis in Being and Nothingness, his arguments and theories are conveniently summarized in his novels, short stories, and plays. For example, one of his most gripping plays, No Exit, was written in 1944, just one year after Being and Nothingness. As a result, many of the themes and symbolism in the play support and condense Sartre's arguments in the larger (and longer) philosophical work.
Sartre was interested in the nature of existence, freedom, responsibility, consciousness, and time, helping to develop a philosophical movement called existentialism. Sartre defined existentialism as the doctrine that "existence precedes essence." He distinguished between inanimate objects, or a "being-in-itself," and human consciousness, or a "being-for-itself." For example, consider a computer mouse. Its essence is the quality or qualities that one would use to describe it, such as its shape, color, smoothness, and weight. Its existence results from the fact that it plainly is. This distinction means that the observer "creates" the essence of the object simply by being conscious of it. The computer mouse is thus a "being-in-itself": its character has been assigned to it. But a person's emotions are not the same as a mouse's color. Sartre claimed that if one is happy it is by his or her own free choice. In this sense, humans exist and then define and choose their essence. Someone who has no fixed character consciously decides his or her essence and is thus a "being-for-itself."
War and tragedy influenced many of Sartre's ideas. For example, the Spanish Civil War and the worldwide economic crisis instigated many of his writings during the 1930s. Nevertheless, World War II had an enormous effect on Sartre's life both physically and intellectually. When war broke out in 1939 Sartre joined the French Army, but was quickly captured and imprisoned. After France's capitulation in 1940, Germany occupied most of France, including Paris. Sartre and many men like him were allowed to return to Paris. He immediately joined the French Resistance, organizing meetings and writing for clandestine newspapers. In his small circle of intellectuals participating in the Resistance, Sartre was able to develop many of his ideas with future literati, including Simone de Beauvoir and Albert Camus.
Faced with the humiliation of defeat and the suffering of war and occupation, Sartre examined many of his questions about existence with respect to World War II. For example, No Exit, which takes place in a room in hell occupied by three people who can't stand each other, has often been compared to living in Paris during the German occupation. In this context, Sartre examined such issues as freedom, self-deception, and the nature of time in the play to help fellow French men and women cope with the ordeal of defeat both during the war and after.