This thesis argues that the ethical nihilism of Jean-Paul Sartre's Being and Nothingness is a product of his position that the for-itself exists for the purpose of founding the in-itself. This position, which I call Sartre's creation myth, cannot be supported by either his ontology, that requires that consciousness be spontaneous, nor his theory of value. The creation myth underlies the theses in Sartre's text that bad faith is inevitable and that reflection cannot produce new values. By exposing the workings of the myth as it conflicts with Sartre's work, and especially his theory of value, reflection is rehabilitated and some of the obstacles to an existentialist ethics are removed.