What should we required to be proved about a particular instance, in order to say that the name was wrongly applied to it? And the test which is thus applied both to virtues and to duties, and considered to be final, is the question: Is it a means to good? If it could be shewn of any particular disposition, commonly considered virtuous, that it was generally harmful, we should at once say: Then it is not really virtuous. Accordingly a virtue may be defined as an habitual disposition to perform certain actions, which generally produce the best possible results. Nor is there any doubt as to the kind of actions which it is ‘virtuous’ habitually to perform. They are, in general, those which are duties, with this modification that we also include those which would be duties, if only it were possible for people in general to perform them. Accordingly with regard to virtues, the same conclusion holds as with regard to duties. If they are really virtues they must be generally good as means; nor do I wish to dispute that most virtues, commonly considered as such, as well as most duties, really are means to good. But it does not follow that they are a bit more useful than those dispositions and inclinations which lead us to perform interested actions. As duties from expedient actions, so virtues are distinguished from other useful dispositions, which it is particularly useful to praise and to sanction, because there are strong and common temptations to neglect the actions to which they lead.
Virtues, therefore, are habitual dispositions to perform actions which are duties, or which would be duties if a volition were sufficient on the part of most men to ensure their performance. And duties are a particular class of those actions, of which the performance has, at least generally, better total results than the omission. They are, that is to say, actions generally good as means: but not all such actions are duties; the name is confined to that particular class which it is often difficult to perform, because there are strong temptations to the contrary. It follows that in order to decide whether any particular disposition or action is a virtue or a duty, we must face all the difficulties enumerated in section (3) of this chapter.
