dc.description.abstract | Reductive naturalistic moral realist theories, or reductive naturalist theories for short, make the metaethical claim that moral facts are real and reducible to natural facts. Thus descriptions of what we ought to do, from a typically other-regarding or social perspective, can justifiably be held as real facts reducible to natural facts. In this thesis I identify two related challenges to which reductive naturalist theories must face up. These challenges both concern normativity. The first asks whether moral facts, when reduced to natural facts, can still be normative in any adequate sense. The second asks specifically whether moral facts can, after their reduction, still be adequately normative for individuals. I assess the answers to these questions as given by a particular reductive naturalist theory: that of Peter Railton. I first argue that Railton successfully defends the general normativity of moral facts as reducible to natural facts, since social groups always have a strong reason to abide by moral standards as much as they can. However, I also argue that Railton does not succeed in justifying the universal rational demand that many of us believe moral facts to place on individuals. On Railton’s view, individuals can, from their own perspective rationally break and disregard moral rules when their interests make this beneficial. I argue that this normative limitation of Railton’s moral facts constitutes a problem for his reductive project, to the effect that there seems to be more to morality than his theory is able to reduce to natural facts. I finally argue that we ought to reject his theory as it stands, as opposed to modifying our understanding of moral facts to allow their complete reduction on Railton’s theory. | |