  Although natural abilities of the mind are not traditionally classified as moral virtues and vices, the difference between these types of traits is unimportant, Hume argues. Intelligence, good judgment, application, eloquence, and wit are also mental qualities that bring individuals the approbation of others, and their absence is disapproved. As is the case with many of the traditionally-recognized virtues, the various natural abilities are approved either because they are useful to their possessor or because they are immediately agreeable to others. It is sometimes argued that moral virtues are unlike natural abilities in that the latter are involuntary, but Hume argues that many traditional moral virtues are involuntary as well. The sole difference is that the prospect of reward or punishment can induce people to act as the morally virtuous would (as justice requires, for example), but cannot induce them to act as if they had the natural abilities.