Desires, reasons, and rationality

Derek Parfit, Joseph Raz, and T. M. S canlon, among others, all hold that reasons for action are provided by facts about those actions. They also hold that the fact that an action would promote or achieve the object of an agent's desire is not one of the relevant facts, and does not provide a reason. Rather, the facts that provide reasons are typically facts about valuable states of affairs that the action is likely to bring about, or valuable properties that the action itself will instantiate. For this reason it is appropriate to call Parfit, Raz, and Scanlon "value-based" theorists about reasons for action. In contrast to value-based theorists, there is a strong current of contemporary theorizing, starting with Bernard Williams, that can be called "desire-based." Desire-based theorists argue that practical reasons should be understood in terms of the desires of the agents who are said to have those reasons