Appeals to human nature have a strong and ancient history in moral philosophy, and in contemporary bioethics that tradition remains vibrant. In order to interpret our relationships with one another and the world around us, it makes good sense to begin with an understanding of what we cherish about being human. Doing so can, in theory, help identify features of the human experience we should always strive to preserve, and set aspirational goals for our actions with respect to the rest. In the practical contexts of bioethics and science policy, however, developing or adopting a universal, normative account of human nature as a prerequisite to decision-making is never an option, since such an account is perennially “in process.” The best that these analysts can hope for is to snatch from the ongoing project of philosophical anthropology insights and ideas about particular aspects of human nature that can be helpful in their tasks at hand. In doing so, of course, they import into their policy-making deep, competing, and even incommensurable philosophical assumptions, on which no public or philosophical consensus may exist. This makes their arguments easy to demolish, on both logical and political grounds. So easy, in fact, that the real messages of such appeals are often swept aside with the debris, and lost.