Hume’s moral philosophy is a distinctive and inﬂuential combination of virtue ethics and moral sense theory (or sentimentalism). For him, VIRTUE and VICE are the fundamental normative concepts structuring the moral domain of value through their application to character, while the concepts used in the moral evaluation of actions derive their normativity from these [5.1]. In this he stands with the ancient moralists he admired and in opposition to those who treat the evaluation of actions for conformity to duty as fundamental. In particular, he stands in substantial opposition to the long tradition of natural law tracing back at least to Thomas Aquinas (1225-74) and renewed in modern Protestant Europe by Hugo Grotius (1583-1645), Samuel Pufendorf (163294), and John Locke. In this tradition, the evident need for human beings to preserve themselves and to live together socially permits the derivation of moral precepts that can be known by reason, even without revelation, to have the force of moral law as commands of God. At the same time, VIRTUE and VICE are for Hume also immediately
sense-based concepts that arise from a moral sense consisting in the capacity to feel pleasurable moral approbation or painful moral disapprobation [4.1]. In this he stands with philosophers like Shaftesbury and Hutcheson who model the epistemology of moral qualities partly on that of the secondary qualities of bodies, and in opposition not only to natural law theorists, but also to philosophers like Clarke and Malebranche who model the epistemology of morality partly on that of mathematics. Whereas Hutcheson treats the moral sense as directed primarily
at actions performed from benevolence, however, Hume maintains
that a wide range of mental traits and characteristics are equally capable of stimulating the moral sense. When the mind feels nonmoral pleasures or pains and regards them as caused by a mental characteristic it is considering, the result is the distinctively moral pleasure or pain of moral approbation or disapprobation, respectively. Typically, though not quite always (THN 18.104.22.168/577-78; THN 22.214.171.124-29/589-90), these non-moral pleasures and pains are felt through the operation of sympathy [3.6]; and moral sentiments themselves can also be strengthened or spread to others by sympathy. Hume draws a number of important distinctions among kinds of
virtues. One way to classify them, especially prominent in the organization of the second Enquiry, is by means of their primary source of appeal to the moral sense as delineated in the four-part productive deﬁnition of ‘virtue’ or ‘personal merit’ as mental characteristics that are useful or agreeable to their possessor or others [4.2]. Books of moral guidance of the period often drew a tripartite distinction among duties to God, duties to self, and duties to others. It would therefore have been notable that Hume omits any mention of duties to God. This omission and his positive location of the source of moral distinctions in features of distinctively human passions and taste are central to his irreligious and naturalistic philosophical purposes. Another important distinction of kinds of virtues for Hume-
especially prominent in the organization of Treatise Book 3-is that between “natural” and “artiﬁcial” virtues. The latter, unlike the former, depend for their existence on conventions and artiﬁce. Within the natural virtues, those of “greatness of mind” are especially related to pride, while those of “goodness and benevolence” are particularly related to love. Still other natural virtues are among those often classiﬁed as mere “natural abilities.” He distinguishes “moral obligation” from what he calls “interested” (also “self-interested” or “natural”) obligation, and he argues that there is in general an interested obligation, as well as a moral obligation, to virtue. This conclusion is central to his practical aim of encouraging virtue. Like the sense-based concepts PROBABILITY, BEAUTY, and DEFORMITY, the concepts of VIRTUE and VICE require some relativization to circumstances [4.4] and allow some scope for blameless diversity [4.2].