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.
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.
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
