Christine M. Korsgaard and Jean-Paul Sartre both locate the source of ethical normativity in human reflective consciousness. Korsgaard’s claims that human beings are essentially rational, and that our rational nature is an adequate source of ethical content. Sartre argues that a conception of human nature this minimal is insufficient to provide ethical content, and that we must look to our particular projects and identities to provide moral content. I will argue that Sartre is correct that a view of human nature this minimal is inadequate to generate moral content, but that because Sartre is unable to demonstrate how norms based contingent projects and identities can produce universally binding ethical norms, his theory also fails. The failure of both projects illustrates the weakness of a conception of ethics as universal obligation because it fails by its own standard to produce it goal of universally binding ethical norms with content
