Ethics, supervenience and Ramsey sentences

Abstract

The paper criticizes Frank Jackson’s account of ethics in From Metaphysics to Ethics, especially his argument that if ethical truths supervene on descriptive truth then ethical properties are coextensive with descriptive properties. Although that does follow from stronger supervenience claims, they are more dubious than the one Jackson cites. The paper also criticizes Jackson’s moral functionalism. His use of modified Ramsey sentences to define ethical predicates assumes that a unique sequence of properties satisfies folk morality. If folk morality is weak enough to guarantee its satisfaction, it may be weak enough to be multiply satisfied.