  Contemporary philosophers recognize the possibility that sentences that express identities might be synthetic as opposed to analytic or true by definition. We can discover that water is the same stuff as H2O without being able to infer it from the meanings of the terms involved (Kripke 1972; Putnam 1975a). And descriptive naturalists about morality have pointed out that the openness of Moore’s question to competent speakers does not rule out the possibility of securing the identity of a moral property with a naturalistic property through empirical discoveries that do not rely on the expressions in question having the same meaning (Boyd 1988). Yet many contemporary defenders of non-cognitivism suggest that the open question argument still provides ammunition for their claims. Even if we cannot infer from the openness of a question that the referents of two terms used to ask that question are distinct, we might still have reason to think that the two expressions do not mean the same thing. Thus non-cognitivists have used the open question argument to suggest that moral terms contain a normative element completely lacking in descriptive terms and which should be cashed out along the lines that the non-cognitivists favor.