The first to anticipate existentialism's major concerns was 17th-century French philosopher Blaise Pascal, who denounced a systematic philosophy that presumes to explain God and humanity. He saw life in terms of paradoxes: The human self, combining mind and body, is itself a contradiction. Later, Soren Kierkegaard rejected a total rational understanding of humanity and history, stressing the ambiguity and absurdity of the human situation.Nineteenth-century German philosopher Friedrich Nietzsche espoused tragic pessimism and life-affirming individual will. Martin Heidegger argued that human beings can never hope to understand why they are here; instead, each individual must choose a goal and follow it with passionate conviction, aware of the certainty of death and the ultimate meaninglessness of one's life. Twentieth-century French philosopher Jean Paul Sartre first gave the term existentialism general currency by using it for his own philosophy. Explicitly atheistic and pessimistic, his philosophy declared that human life requires a rational basis but the attempt is a "futile passion." Nevertheless, he insisted that his view is a form of humanism, emphasizing freedom and responsibility.
Although it encompasses atheism and agnosticism, existentialist thought has had a profound influence on 20th-century theology, addressing such issues as transcendence and the limits of human experience, as well as a personal sense of authenticity and commitment. Existentialism has been a vital movement in literature, particularly in the works of Russian novelist Fyodor Dostoyevsky, Austrian writer Franz Kafka, and French writer Albert Camus. It is also prominent in the theater of the absurd, notably in the plays of Irish-born writer Samuel Beckett and Romanian-born French writer Eugène Ionesco. (from Encarta Concise Encyclopedia)