 By contrast with the law, morality is a sharp instrument. Morality can be, and typically ought to be, made to apply to a given situation in all its particularity. (This is, of course, not to say that there are not recurring moral situations in respect of which the same moral judgment should be made, nor is it to say that morality does not need to help itself to generalisations.) Accordingly, what might be, all things considered, the morally best action for an agent to perform in some one-off, i.e. non-recurring, situation might not be an action that should be made lawful. Consider the real-life example of the five sailors on a raft in the middle of the ocean and without food. Four of them decide to eat the fifth – the cabin boy – in order to  survive.[17]  This is a case of both murder and cannibalism. Was it morally permissible to kill and eat the boy, given the alternative was the death of all five sailors? Clearly it was not pro tanto morally permissible, especially given the cabin boy was entirely innocent; but perhaps it was morally permissible all things considered. And even if it was not morally permissible all things considered, nevertheless, arguably it was morally excusable, and indeed the sailors, although convicted of murder and cannibalism, had their sentence commuted in recognition of this. But there was no suggestion that the laws against murder and cannibalism admit of an exception in such an extreme case; the sailors were convicted and sentenced for murder and cannibalism. Again, consider an exceptionless law against desertion from the battlefield in time of war. Perhaps a soldier is morally justified in deserting his fellow soldiers, given that he learns of the more morally pressing need for him to care for his wife who has contracted some life-threatening disease back home. However, the law against desertion will not, and should not, be changed to allow desertion in such cases.