The title of this article refers to Beauvoir's essay "Must We Burn De Sade?" (1953/1952). Analogous to Beauvoir's essay on Sade, this article is something of an apology for Foucault. I use Beauvoir's essay on Sade to discuss Foucault's concept of ethics as an art of living. I conclude that the final Foucault's thought on ethics can be labelled a post-existentialism, combining postmodern thinking and the issues of freedom and commitment in an inspiring way. I argue, however, that the heuristics of Foucault's later work is undertheorized. Comparing Foucault's approach with Beauvoir's own concept of ethics as art of living shows hers to be superior in that it has a place for the emotions. The cold stoicism of the final Foucault only deals with emotion from the point of view of repression and sublimation. Foucault's post-existentialism must therefore be enriched with Beauvoir's concepts. I conclude that aspects of the theoretical frameworks of both Foucault and Beauvoir can contribute to the solution of some of the dilemmas of postmodern thinking with respect to politics and political theory.