Normative reasons and the possibility of motivation

This article defends a claim about the conditions under which agents possess normative reasons for action. According to this claim, an agent has a normative reason to phi only if it's psychologically possible for that reason to motivate the agent to phi. The claim is called Williams's explanatory constraint', since it's drawn from Bernard Williams's work on the topic of practical reason. A two-premise master argument' for Williams's explanatory constraint is put forward. First, an agent has a normative reason to phi only if that agent has the ability to phi for that reason. The second premise states that an agent has the ability to phi for a normative reason only if it's psychologically possible for that reason to motivate the agent to phi. It is suggested that the ability to act for a normative reason involves the ability to act from a consequence-sensitive process of practical reasoning. Furthermore, normative reasons for action can motivate agents by being the objects of psychological states - particularly beliefs, desires and intentions. In reply to the objection that normative reasons can never be objects of psychological states, I contend that all normative reasons are capable of being represented as the objects of psychological states.