Reasons internalists claim that facts about normative reasons for action are facts about which actions would promote an agent’s goals and values. Reasons internalism is popular, even though paradigmatic versions have moral consequences many find unwelcome. This article reconstructs an influential but understudied argument for reasons internalism, the “if I were you” argument, which is due to Bernard Williams and Kate Manne. I raise an objection to the argument and argue that replying to it requires reasons internalists to accept controversial (...) metaethical or epistemological commitments with which their theory has not traditionally been associated. (shrink)