Hume’s Legacy and the Curate’s Egg

An important part of the Humean legacy in metaethics would be unacceptable to Hume himself, viz., the argument for moral non-cognitivism based on Humean moral psychology. This argument would be unacceptable to Hume because it requires the premise of motivational internalism: “Necessarily, if one judges an act right, then one is motivated to act in accordance with that judgment.” This premise asserts a universal, necessary connection between an agent’s moral judging and that agent’s being motivated to act accordingly, but it also violates Hume’s claim that the only true propositions asserting universal, necessary connections are about “relations of ideas.” But motivational internalism cannot be about relations of ideas, because it fails the contradiction test in “Hume’s Fork.”