. . . not only do we assert that the existentialist doctrine permits the elaboration of an ethics, but it even appears to us as the only philosophy in which an ethics has its place. For, in a metaphysics of transcendence, in the classical sense of the term, evil is reduced to error; and in humanistic philosophies it is impossible to account for it, man being defined as complete in a complete world. Existentialism alone gives — like religions — a real role to evil, and it is this, perhaps, which makes its judgments so gloomy. Men do not like to feel themselves in danger. Yet it is because there are real dangers, real failures and real earthly damnation that words like victory, wisdom, or joy have meaning. Nothing is decided in advance, and it is because man has something to lose and because he can lose that he can also win.
— Simone de Beauvoir, from The Ethics of Ambiguity