(α) Since, as I have tried to shew, it is impossible to establish that any kind of action will produce a better total result than its alternative _in all cases_, it follows that in some cases the neglect of an established rule will probably be the best course of action possible. The question then arises: Can the individual ever be justified in assuming that his is one of these exceptional cases? And it seems that this question may be definitely answered in the negative. For, if it is certain that in a large majority of cases the observance of a certain rule is useful, it follows that there is a large probability that it would be wrong to break the rule in any particular case; and the uncertainty of our knowledge both of effects and of their value, in particular cases, is so great, that it seems doubtful whether the individual’s judgment that the effects will probably be good in his case can ever be set against the general probability that that kind of action is wrong. Added to this general ignorance is the fact that, if the question arises at all, our judgment will generally be biassed by the fact that we strongly desire one of the results which we hope to obtain by breaking the rule. It seems, then, that with regard to any rule which is _generally_ useful, we may assert that it ought _always_ to be observed, not on the ground that in _every_ particular case it will be useful, but on the ground that in _any_ particular case the probability of its being so is greater than that of our being likely to decide rightly that we have before us an instance of its disutility. In short, though we may be sure that there are cases where the rule should be broken, we can never know which those cases are, and ought, therefore, never to break it. It is this fact which seems to justify the stringency with which moral rules are usually enforced and sanctioned, and to give a sense in which we may accept as true the maxims that ‘The end never justifies the means’ and ‘That we should never do evil that good may come.’ The ‘means’ and the ‘evil,’ intended by these maxims, are, in fact, the breaking of moral rules generally recognised and practised, and which, therefore, we may assume to be generally useful. Thus understood, these maxims merely point out that, in any particular case, although we cannot clearly perceive any balance of good produced by keeping the rule and do seem to see one that would follow from breaking it, nevertheless the rule should be observed. It is hardly necessary to point out that this is so only because it is certain that, in general, the end does justify the means in question, and that therefore there is a _probability_ that in this case it will do so also, although we cannot see that it will.