Moral language displays a characteristic duality. On the one hand, moral claims seem to be similar to descriptive claims: To say that an act is right seems to be a matter of making an assertion, thus indicating that the speaker has a moral belief about which she can be correct or mistaken. On the other hand, moral claims seem to be different from descriptive claims: There is a sense in which, by claiming that an act is right, a speaker indicates (...) that she is inclined to perform the act, to want others to perform it, and to react with praise towards those who do it. Hybrid theories maintain that utterances of moral sentences have both a descriptive and a practical linguistic function. In this thesis, I investigate how a hybrid theory can best accommodate the descriptive and the practical aspects of moral language. I evaluate and criticize the way that existing hybrid theories have proposed to explain the duality of moral language. The main arguments against these views are that they either: fail to accommodate the way that the practical or attitudinal import of moral claims vary across different contexts and linguistic environments; or that they fail to show how the practical or attitudinal import is reliably inferred by interlocutors in virtue of general communicative principles. I develop and defend a new hybrid theory called ‘dynamic descriptivism’. This theory accommodates the duality of moral language by appeal to the way that moral utterances affect a dimension of communication which consists of the shared assumptions that interlocutors mutually assume to mutually accept. Moreover, I discuss a problem which has affected a wide range of theories of moral language – including existing hybrid theories – which is the problem of explaining what it is that interlocutors disagree about when they disagree about matters of morality. I argue that that dynamic descriptivism offers new resources for solving this problem. (shrink)

According to one influential response to evolutionary debunking arguments against moral realism, debunking arguments fail to undermine our moral beliefs because they fail to imply that those beliefs are insensitive or unsafe. The position that information about the explanatory history of our belief must imply that our beliefs are insensitive or unsafe in order to undermine those beliefs has been dubbed “Modal Security”, and I therefore label this style of response to debunking arguments the “modal security response”. An alternative position, (...) that our beliefs can be defeated if we accept those beliefs are not explained by the relevant facts, I call “explanationism”. In this article, I argue against Modal Security in favour of explanationism. First, I present two examples from the literature that appear to support explanationism, and I argue that these examples imply that the modal security response is fundamentally misguided about the nature of epistemic defeat. I then consider a recent response from Justin Clarke-Doane and Dan Baras, who claim that examples of this kind fail because they are either incoherent or involve a failure of modal security. I argue that, due to their position on the failure of evolutionary debunking arguments, Clarke Doane and Dan Baras are committed to the existence of coherent, sufficiently simple examples that can help us arbitrate between explanationism and modal security. I then construct such an example and argue that it clearly indicates that we should reject Modal Security in favour of explanationism. This implies the modal security response to debunking arguments fails. (shrink)