For millennia, philosophers have speculated about the origins of ethics. Recent research in evolutionary psychology and the neurosciences has shed light on that question. But this research also has normative significance. A standard way of arguing against a normative ethical theory is to show that in some circumstances the theory leads to judgments that are contrary to our common moral intuitions. If, however, these moral intuitions are the biological residue of our evolutionary history, it is not clear why we should regard them as having any normative force. Research in the neurosciences should therefore lead us to reconsider the role of intuitions in normative ethics.