After World War I many artists and intellectuals experienced a crisis of faith in Western civilization. Contemplating the war's destructiveness and brutality, these thinkers could no longer believe in the saving powers of reason, science, and progress. Instead, intellectuals and artists viewed post-war civilization with pessimism and foreboding. One of the most influential expressions of this pessimism was that of Spengler, who saw the modern West in the last stages of decadence before its final collapse.

Writers and artists variously responded to this crisis of civilization. For example, Kafka envisioned a modern world without apparent order, in which individuals are crushed by cruel forces beyond their understanding. Mann dramatized the conflict between a weak liberalism and the forces of irrationalism and authoritarianism. Viewing reason as an oppressive force, Lawrence extolled sexual liberation and instinctual life. Other writers took up humanitarian causes, protesting war and the effects of poverty. The Dadaists proclaimed the absurdity of life and represented it through deliberately senseless art works. The surrealists embraced the Freudian unconscious, seeking to make it the source of spontaneous creativity. Socially conscious artists denounced moral degeneration, political oppression, and wartime suffering.

In the face of economic crisis and rising fascist power, many intellectuals sought coherent value systems. Some turned to communism as an alternative to capitalist injustice, but many, such as Koestler, later rejected it after perceiving the realities of Stalin's regime. Other intellectuals turned to Christianity, arguing at the West could survive the onslaught of irrationalism only by reembracing faith in revealed truth. Still other thinkers reaffirmed Enlightenment values, setting critical reason against the barbarism and mythical thinking of fascism.

The most representative philosophical movement to emerge during this period was existentialism. Although not a unified movement, existentialism adheres to a few basic principles concerning the absurdity of existence, the limits of reason, and the capacity for choice in life. The major existentialists articulated these principles from various points of view, from the religious orientation of Buber and Marcel at one extreme, to the staunch atheism of Sartre and Camus on the other.

Together, these artistic and philosophical enterprises amount to a creative response to the questions raised by World War I and its aftermath-questions concerning the course of civilization, the efficacy of reason, the consequences of science, and the meaning of existence. World War II would make these questions all the more urgent.