It is plain, then, that the rules commonly recognised by Common Sense, in the society in which we live, and commonly advocated as if they were all equally and universally right and good, are of very different orders. Even those which seem to be most universally good as means, can only be shewn to be so, because of the existence of conditions, which, though perhaps evils, may be taken to be necessary; and even these owe their more obvious utilities to the existence of conditions, which cannot be taken to be necessary except over longer or shorter periods of history, and many of which are evils. Others seem to be justifiable solely by the existence of such more or less temporary conditions, unless we abandon the attempt to shew that they are means to that preservation of society, which is itself a mere means, and are able to establish that they are directly means to things good or evil in themselves, but which are not commonly recognised to be such. (§ 98 ¶ 1)

If, then, we ask what rules are or would be useful to be observed in the society in which we live, it seems possible to prove a definite utility in most of those which are in general both recognised and practised. But a great part of ordinary moral exhortation and social discussion consists in the advocating of rules, which are not generally practised; and with regard to these it seems very doubtful whether a case for their general utility can ever be conclusively made out. Such proposed rules commonly suffer from three main defects. In the first place (1) the actions which they advocate are very commonly such as it is impossible for most individuals to perform by any volition. It is far too usual to find classed together with actions, which can be performed, if only they be willed, others, of which the possibility depends on the possession of a peculiar disposition, which is given to few and cannot even be acquired. It may, no doubt, be useful to point out that those who have the necessary disposition should obey these rules; and it would, in many cases, be desirable that everybody should have this disposition. But it should be recognised that, when we regard a thing as a moral rule or law, we mean that it is one which almost everybody can observe by an effort of volition, in that state of society to which the rule is supposed to apply. (2) Actions are often advocated, of which, though they themselves are possible, yet the proposed good effects are not possible, because the conditions necessary for their existence are not sufficiently general. A rule, of which the observance would produce good effects, if human nature were in other respects different from what it is, is advocated as if its general observance would produce the same effects now and at once. In fact, however, by the time that the conditions necessary to make its observance useful have arisen, it is quite as likely that other conditions, rendering its observance unnecessary or positively harmful, may also have arisen; and yet this state of things may be a better one than that in which the rule in question would have been useful. (3) There also occurs the case in which the usefulness of a rule depends upon conditions likely to change, or of which the change would be as easy and more desirable than the observance of the proposed rule. It may even happen that the general observance of the proposed rule would itself destroy the conditions upon which its utility depends. (§ 98 ¶ 2)

One or other of these objections seems generally to apply to proposed changes in social custom, advocated as being better rules to follow than those now actually followed; and, for this reason, it seems doubtful whether Ethics can establish the utility of any rules other than those generally practised. But the inability to do so is fortunately of little practical moment. The question whether the general observance of a rule not generally observed, would or would not be desirable, cannot much affect the question how any individual ought to act; since, on the one hand, there is a large probability that he will not, by any means, be able to bring about its general observance, and, on the other hand, the fact that its general observance would be useful could, in any case, give him no reason to conclude that he himself ought to observe it, in the absence of such general observance. (§ 98 ¶ 3)

With regard, then, to the actions commonly classed in Ethics, as duties, crimes, or sins, the following points seem deserving of notice. (1) By so classing them we mean that they are actions which it is possible for an individual to perform or avoid, if he only wills to do so; and that they are actions which everybody ought to perform or avoid, when occasion arises. (2) We can certainly not prove of any such action that it ought to be done or avoided under all circumstances; we can only prove that its performance or avoidance will generally produce better results than the alternative. (3) If further we ask of what actions as much as this can be proved, it seems only possible to prove it with regard to those which are actually generally practised among us. And of these some only are such that their general performance would be useful in any state of society that seems possible; of others the utility depends upon conditions which exist now, but which seem to be more or less alterable. (§ 98 ¶ 4)