Some philosophers hold that ‘ought’ is ambiguous between a sense expressing a propositional operator and a sense expressing a relation between an agent and an action. We defend the opposing view that ‘ought’ always expresses a propositional operator against objections that it cannot adequately accommodate an ambiguity in ‘ought’ sentences between evaluative and deliberative readings, predicting...

Moral philosophy in the English-speaking world has been dominated during the present century by the controversy concerning the logical relationship between 'is' and 'ought'. These terms are, of course, to be understood in the present context as shorthand labels. By 'is' is meant any non-moral assertion, that is to say, any utterance which purports to be either true or false and which does not e...

Ethical theorists often assume that the verb ‘ought’ means roughly ‘has an obligation’; however, this assumption is belied by the diversity of ‘flavours’ of oughtsentences in English. A natural response is that ‘ought’ is ambiguous. However, this response is incompatible with the standard treatment of ‘ought’ by theoretical semanticists, who classify ‘ought’ as a member of the family of modal v...