existentialism

A 20th-century philosophical movement emphasizing the uniqueness of each human existence in freely making its self-defining choices.

The heyday of existentialism occurred in the mid-twentieth century.

The philosophical views of a particular thinker associated with the existentialist movement.

Sartre's existentialism is atheistic, but the existentialism of Marcel is distinctly Christian.

Instead of Existentialism, we should speak of Existentialisms.