In this section of the Enquiry, Hume examines still further the way in which moral sentiments are influenced by one's observation of qualities found in the lives of other people. For example, indolence, negligence, carelessness, credulity, fickleness, and similar qualities are not regarded as praiseworthy even though they may give immediate satisfaction and pleasure to the persons who possess them. The fact that these qualities are detrimental to the best interests of these persons by making them less capable of carrying on business transactions and performing other useful activities is something that gives to the observer a sentiment of disapproval and a feeling of uneasiness. It is from feelings of this type that one derives a sense of obligation or duty to avoid the development of these same qualities within himself.
The qualities which have been mentioned are not absolutely bad in the sense that no amount of them is ever desirable under any circumstances. Rather, it is the Aristotelian doctrine of the golden mean which should be followed with reference to each of them. Qualities which are desirable when present in the right amount and under the right circumstances become detrimental to one's interests when there is either a deficiency or an excessive amount of them. The right amount is determined not by the way one feels about it at the moment but by a reasonable calculation with reference to one's entire nature and the proper development of his personality as a whole.
It is the possession of these qualities in something other than the right amount that gives rise to the sense of disapproval on the part of the one who observes them. Quite the opposite occurs when the same qualities are present in the right amount, for this gives to the observer a sense of easiness and satisfaction which is characteristic of the virtues. In all instances, it is the utility of the qualities in question that determines whether they shall be regarded as virtues or as vices.
