In an article published in this journal in 1973, Professor George P. Fletcher maintained that there ought to be no limitation of proportionality on the exercise of self-defense. The requirement of proportionality signifies that there is a limit to the price society is willing or agreeable to pay for the protection of a legitimate interest against an unlawful attack. The right to use self-defense therefore rests upon the condition that there be some kind of relationship, which is not one of equivalence, between the interest attacked and that sacrificed in order to save it. In the absence of such a relationship, self-defense may not be employed. Thus, for example, in the case of a petty theft, if the interest attacked (ownership or possession of the property) can be defended only by inflicting serious injury—death or grievous bodily harm—upon the aggressor, one must refrain from doing so, even if this means sacrificing the interest at stake. If self-defense is not circumscribed by the requirement of proportionality, then the owner of an apple orchard who shoots and kills a thief, lacking any other means of stopping him from running off with the fruit he has stolen, will bear no criminal responsibility for his act.
Bodily Modifications and the Criminal Law