In Rethinking Existentialism, Jonathan Webber articulates an original interpretation of existentialism as the ethical theory that human freedom is the foundation of all other values. Offering an original analysis of classic literary and philosophical works published by Jean-Paul Sartre, Simone de Beauvoir, and Frantz Fanon up until 1952, Webber's conception of existentialism is developed in critical contrast with central works by Albert Camus, Sigmund Freud, and Maurice Merleau-Ponty.

Presenting his arguments in an accessible and engaging style, Webber contends that Beauvoir and Sartre initially disagreed over the structure of human freedom in 1943 but Sartre ultimately came to accept Beauvoir's view over the next decade. He develops the viewpoint that Beauvoir provides a more significant argument for authenticity than either Sartre or Fanon. He articulates in detail the existentialist theories of individual character and the social identities of gender and race, key concerns in current discourse. Webber concludes by sketching out the broader implications of his interpretation of existentialism for philosophy, psychology, and psychotherapy.