The primary concern of this paper is Hume's account of the moral difference between humans and other animals. In order to clarify this difference Hume's views regarding reason, sympathy, and human sentiment are examined. The purpose of this investigation is threefold. First, Hume's position on the moral difference between humans and other animals is clarified. It is argued that this difference is properly traced to Hume's account of the sentiment of humanity. Second, Hume is defended against the claim that his (...) position on this matter is inconsistent. Third, it is argued that Hume's theory of morality leaves open the possibility that some earthly species other than our own may be properly understood as moral. (shrink)