  In the Treatise Hume emphasizes that “our sense of every kind of virtue is not natural; but … there are some virtues, that produce pleasure and approbation by means of an artifice or contrivance, which arises from the circumstances and necessities of mankind” (T 3.2.1.1). He divides the virtues into those that are natural — in that our approval of them does not depend upon any cultural inventions or jointly-made social rules — and those that are artificial (dependent both for their existence as character traits and for their ethical merit on the presence of conventional rules for the common good), and he gives separate accounts of the two kinds. The traits he calls natural virtues are more refined and completed forms of those human sentiments we could expect to find even in people who belonged to no society but cooperated only within small familial groups. The traits he calls artificial virtues are the ones we need for successful impersonal cooperation; our natural sentiments are too partial to give rise to these without intervention. In the Treatise Hume includes among the artificial virtues honesty with respect to property (which he often calls equity or “justice,” though it is a strangely narrow use of the term), fidelity to promises (sometimes also listed under “justice”), allegiance to one’s government, conformity to the laws of nations (for princes), chastity (refraining from non-marital sex) and modesty (both primarily for women and girls), and good manners. A great number of individual character traits are listed as natural virtues, but the main types discussed in detail are greatness of mind (“a hearty pride, or self-esteem, if well-concealed and well-founded,” T 3.2.2.11), goodness or benevolence (an umbrella category covering generosity, gratitude, friendship, and more), and such natural abilities as prudence and wit, which, Hume argues, have a reasonably good claim to be included under the title moral virtue, though traditionally they are not. Hume does not explicitly draw a distinction between artificial and natural virtues in the moral Enquiry.