But it is to be noticed that none of these characteristics, by which a “duty” is distinguished from an expedient action, gives us any reason to infer that the former class of actions are more useful than the latter—that they tend to produce a greater balance of good. Nor, when we ask the question, “Is this my duty?” do we mean to ask whether the action in question has these characteristics: we are asking simply whether it will produce the best possible result on the whole. And if we asked this question with regard to expedient actions, we should quite as often have to answer it in the affirmative as when we ask it with regard to actions which have the three characteristics of “duties.” It is true that when we ask the question, “Is this expedient?” we are asking a different question—namely, whether it will have certain kinds of effect, with regard to which we do not enquire whether they are good or not. Nevertheless, if it should be doubted in any particular case whether these effects were good, this doubt is understood as throwing doubt upon the action’s expediency: if we are required to prove an action’s expediency, we can only do so by asking precisely the same question by which we should prove it a duty—namely, “Has it the best possible effects on the whole?”
Accordingly the question whether an action is a duty or merely expedient, is one which has no bearing on the ethical question whether we ought to do it. In the sense in which either duty or expediency are taken as ultimate reasons for doing an action, they are taken in exactly the same sense: if I ask whether an action is really my duty or really expedient, the predicate of which I question the applicability to the action in question is precisely the same. In both cases I am asking, “Is this event the best on the whole that I can effect?”; and whether the event in question be some effect upon what is mine (as it usually is, where we talk of expediency) or some other event (as is usual, where we talk of duty), this distinction has no more relevance to my answer than the distinction between two different effects on me or two different effects on others. The true distinction between duties and expedient actions is not that the former are actions which it is in any sense more useful or obligatory or better to perform, but that they are actions which it is more useful to praise and to enforce by sanctions, since they are actions which there is a temptation to omit.
102. With regard to “interested” actions, the case is somewhat different. When we ask the question, “Is this really to my interest?” we appear to be asking exclusively whether its effects upon me are the best possible; and it may well happen that what will effect me in the manner, which is really the best possible, will not produce the best possible results on the whole. Accordingly my true interest may be different from the course which is really expedient and dutiful. To assert that an action is “to my interest,” is, indeed, as was pointed out in Chap. III (§§ 59–61), to assert that its effects are really good. “My own good” only denotes some event affecting me, which is good absolutely and objectively; it is the thing, and not its goodness, which is mine; everything must be either “a part of universal good” or else not good at all; there is no third alternative conception “good for me.” But “my interest,” though it must be something truly good, is only one among possible good effects; and hence, by effecting it, though we shall be doing some good, we may be doing less good on the whole, than if we had acted otherwise. Self-sacrifice may be a real duty; just as the sacrifice of any single good, whether affecting ourselves or others, may be necessary in order to obtain a better total result. Hence the fact that an action is really to my interest, can never be a sufficient reason for doing it: by showing that it is not a means to the best possible, we do not show that it is not to my interest, as we do show that it is not expedient. Nevertheless there is no necessary conflict between duty and interest: what is to my interest may also be a means to the best possible. And the chief distinction conveyed by the distinct words “duty” and “interest” seems to be not this source of possible conflict, but the same which is conveyed by the contrast between “duty” and “expediency.” By “interested” actions are mainly meant those which, whether a means to the best possible or not, are such as have their most obvious effects on the agent; which he generally has no temptation to omit; and with regard to which we feel no moral sentiment. That is to say, the distinction is not primarily ethical. Here too “duties” are not, in general, more useful or obligatory than interested actions; they are only actions which it is more useful to praise.
103. (5) A fifth conclusion, of some importance, in relation to Practical Ethics concerns the manner in which “virtues” are to be judged. What is meant by calling a thing a “virtue”?
There can be no doubt that Aristotle’s definition is right, in the main, so far as he says that it is an “habitual disposition” to perform certain
