Moral Disagreement and the Question Under Discussion

If the extension of a moral expression varies depending on the context of utterance, as contextualism maintains, then two speakers who embrace different moral norms or come from different societies might refer to different properties when they use that expression. Contextualism therefore appears unable to accommodate the intuition that such speakers can disagree about moral matters. For instance, a progressive and a conservative might disagree about the permissibility of abortion. But if their moral predicates pick out different properties, what are they disagreeing about? Some have tried to meet this challenge by focusing on the shared assumptions between the interlocutors about their communicative exchange rather than on the semantic contents conveyed by the sentences that the interlocutors assert. This paper presents such an account of moral disagreement that appeals to the questions under discussion (QUDs) that interlocutors mutually assume to be part of the background of their conversation. According to this account, interlocutors who embrace different moral norms can disagree because they accept an opaque QUD, which they are unable to resolve. This account allows contextualists to preserve their core semantic claim that when speakers use moral expressions, the semantic contents of their claims vary across contexts of utterance. But at the mutually presupposed discourse level, the speakers presuppose a common QUD, to which the contents of both their assertions are possible answers.