Existentialism Is a Humanism (French: L'existentialisme est un humanisme) is a 1946 work by the philosopher Jean-Paul Sartre, based on a lecture by the same name he gave at Club Maintenant in Paris, on 29 October 1945.

Anguish leads people to realize that their actions guide humanity and allows them to make judgments about others based on their attitude towards freedom.

"[1] Sartre closes his work by emphasizing that existentialism, as it is a philosophy of action and one's defining oneself, is optimistic and liberating.

[2] An English translation by Carol Macomber, with an introduction by the sociologist Annie Cohen-Solal and notes and preface by Arlette Elkaïm-Sartre, was published under the title Existentialism Is a Humanism in 2007.

Existentialism Is a Humanism has been "a popular starting-point in discussions of existentialist thought,"[4] and in the philosopher Thomas Baldwin's words, "Seized the imagination of a generation.

According to Kaufmann, Sartre makes factual errors, including misidentifying philosopher Karl Jaspers as a Catholic, and presenting a definition of existentialism that is open to question.

[9] Iris Murdoch found one of Sartre's discussions with a Marxist interesting, but otherwise considered Existentialism and Humanism to be "a rather bad little book.

[13] The philosopher Slavoj Žižek argued that there is a parallel between Sartre's views and claims made by the character Father Zosima in Fyodor Dostoyevsky's novel The Brothers Karamazov (1880): whereas Sartre believes that with total freedom comes total responsibility, for Father Zosima "each of us must make us responsible for all men's sins".