Hume's emotivist theory of moral judgements

Hume is believed by many to hold an emotivist thesis, according to which all expressions of moral judgements are expressions of moral sentiments. However, most specialist scholars of Hume either deny that this is Hume's position or believe that he has failed to argue convincingly for it. I argue that Hume is an emotivist and that his true arguments for emotivism have been hitherto overlooked. Readers seeking to understand Hume's theory of moral judgements have traditionally looked to the first section of Book 3 of his Treatise, which discusses the relation between morality and reason. I argue that there is evidence elsewhere that better supports Hume's emotivist thesis. Hume's arguments for emotivism focus more on the causes of moral sentiments than on their relation to reason or belief, and he argues that moral sentiments are such as to arise whenever we contemplate morally relevant objects. He also holds that the presence of moral sentiments precludes any possibility of moral belief, because moral beliefs could only be less vivid copies of moral sentiments, and these cannot simultaneously exist. Hume concludes that all moral judgements must be expressions of sentiments.