Abstract
In her 1947 book Toward an Ethics of Ambiguity, Simone de Beauvoir sketches the outlines of a systematic existentialist ethical theory. This short and startlingly ambitious text purports to offer nothing less than a new way to meet the challenge of moral skepticism with a theory that at once grounds moral normativity and entails certain first-order moral norms. We argue that Beauvoir offers a distinctive and promising version of metaethical constructivism that deserves to be treated as a live option in contemporary debates. Beauvoirian constructivism has much in common with Kantian constructivist approaches to metaethics. It departs from them in that the Beauvoirian existential imperative to will freedom is derived not from rational agency as such but from contingent features of our embodied subjectivity.