Date of Degree


Document Type


Degree Name





Steven Cahn

Subject Categories

Ethics and Political Philosophy


Cornell realism, externalism, metaethics, motivation, naturalism, normativity


Moral realism has been continuously accused of positing the existence of queer properties, facts, judgments, and beliefs. One of these queer features is supposed to be the normative force of morality-that is the way in which morality guides our actions. Critics of moral realism argue that nothing else in the world has this feature. This is a reason to doubt that moral facts and properties exist at all. This objection can be interpreted in at least two ways. One way to interpret it has to do with moral motivation, this is the internalism objection. The other has to do with the authority of morality. In this essay I defend naturalist moral realism against these two objections, the internalism objection and the authority objection. I argue that the internalism objection and the authority objection are independent of each other. Whether and how morality motivates us to act does not bear on the place that morality should have in our lives and decision-making. We may have no motivation to do things that we should do, and we may be extremely motivated to do things we should not do. The conflation of these two objections is widespread in the literature and is the source of some of their apparent persuasiveness. At the same time, I make a case for the opposite view, externalism, which is the view that moral judgments do not necessarily or inherently motivate, nor can they motivate by themselves. Instead moral judgments are only contingently connected with motivation. The specific form of externalism that I argue for is a pluralistic externalism, which I argue can meet the objections that are usually made against externalism better than any alternative form of externalism. The authority objection to naturalist moral realism is that morality has a certain kind of authority over us and that naturalist moral realism precludes this kind of authority. Therefore, naturalist moral realism must be false. The authority of morality can be understood in a variety of ways. For example, the importance that moral demands have in directing our lives or the way in which moral reasons seem to override other reasons for action. The authority of morality is supposed to be a problem for naturalist moral realism because the realist identifies moral facts and properties with complex natural facts and properties. The authority objection asks: why should any set of natural facts or properties have authority over our behavior? In other words, the naturalist moral realist seems to lack a convincing response to this kind of moral skeptic. I respond to the authority objection by defending a limited account of authority. Second, I argue that once properly understood, the authority of morality is no more a problem for naturalist moral realism as a metaethical theory than any other meta-ethical theory. Every metaethical position is faced with the difficult task of explaining this aspect of normativity and we have no reason to think this is a special problem for realism. Finally, I put forward a defensible version of naturalist moral realism, spelling out the commitment to objectivity and to naturalism.