But moreover the universal observance of a rule which is generally useful has, in many cases, a special utility, which seems deserving of notice. This arises from the fact that, even if we can clearly discern that our case is one where to break the rule is advantageous, yet, so far as our example has any effect at all in encouraging similar action, it will certainly tend to encourage breaches of the rule which are not advantageous. We may confidently assume that what will impress the imagination of others will not be the circumstances in which our case differs from ordinary cases and which justify our exceptional action, but the points in which it resembles other actions that are really criminal. In cases, then, where example has any influence at all, the effect of an exceptional right action will generally be to encourage wrong ones. And this effect will probably be exercised not only on other persons but on the agent himself. For it is impossible for any one to keep his intellect and sentiments so clear, but that, if he has once approved of a generally wrong action, he will be more likely to approve of it also under other circumstances than those which justified it in the first instance. This inability to discriminate exceptional cases offers, of course, a still stronger reason for the universal enforcement, by legal or social sanctions, of actions generally useful. It is undoubtedly well to punish a man, who has done an action, right in his case but generally wrong, even if his example would not be likely to have a dangerous effect. For sanctions have, in general, much more influence upon conduct than example; so that the effect of relaxing them in an exceptional case will almost certainly be an encouragement of similar action in cases which are not exceptional.