  A big problem here, it is widely supposed, is the biology. Aristotelian ethics embraces an essentialist, teleological conception of the nature of a species that doesn’t square with modern science. And the prospects for grounding ethics in modern post-Darwinian biology seem hopeless: evolutionary biology has very little (at least of a positive nature) to tell us about metaethics except insofar as it might be taken to add plausibility to the kind of broad naturalism described at the outset. (Indeed, as noted, evolutionary biology may debunk rather than support our moral beliefs.) Nussbaum has sought to respond to claims of this sort that have been ably canvassed in the work of Bernard Williams (Nussbaum 1995). Williams reads Aristotle as understanding questions about human nature as “external” scientific questions to be addressed independently of any ethical considerations. This, Nussbaum charges, is a mistake: an external understanding of human nature would indeed tell us little about ethics. Aristotle’s understanding of biology and indeed science generally is what she calls “internal”, and as such are pervasively informed by substantive ethical understandings. But to understand ethical facts as grounded in facts about human nature, where the facts about human nature are understood in a way that is already pervasively and substantively moralized, no longer looks much like a form of naturalism, and appears quite consistent with a variety of competing metaethical views such as constructivism, expressivism, or non-naturalism.