Naturalism and Moral Reasons

Abstract

Why are traditional ‘objectivist’ theories of morality, such as those put forward by Aristotle, or Kant, or even Bentham, commonly thought not to pass ‘scientific muster’ insofar as they are not ‘naturalist’? My interest in this question is based on my being a moral objectivist, but answering this question is one that moral skeptics should be as interested in as I. The view that the commitments of science preclude us from accepting such theories is the basis of the moral skeptic's position. Yet showing what is wrong with a moral objectivist position is surprisingly difficult. It involves reflecting on what ‘scientific muster’ is supposed to be, and on why a theory is commonly thought to be disreputable unless it passes it. It also involves locating the ‘queer’ element in objectivist moral theory that makes it scientifically disreputable. Yet, as I hope to show in this article, there is no commonly accepted statement of what makes a theory scientifically acceptable or unacceptable, and (perhaps even more surprisingly) no rigorous account of what the queer component of objectivist moral theory is that makes any such theory scientifically unacceptable.