- a philosophical movement that stresses the individual's unique position as a self-determining agent responsible for making meaningful, authentic choices in a universe seen as purposeless or irrational: existentialism is associated especially with Heidegger, Jaspers, Marcel, and Sartre, and is opposed to philosophical rationalism and empiricism.
- a modern philosophical movement stressing the importance of personal experience and responsibility and the demands that they make on the individual, who is seen as a free agent in a deterministic and seemingly meaningless universe
