But whilst public opinion demands that vengeance shall be exacted for injuries, it is also operative in another way. Though in some cases the resentment may seem to outsiders to be too weak or too much checked by other impulses, it may in other cases appear unduly great. As a matter of fact, we frequently find the practice of revenge being regulated by a rule which requires equivalence between the injury and the suffering inflicted in return for {178} it. Sometimes this rule demands that only one life shall be taken for one;[75] sometimes that a death shall be avenged on a person of the same rank, sex, or age as the deceased;[76] sometimes that a murderer shall die in the same manner as his victim;[77] sometimes that various kinds of injuries shall be retaliated by the infliction of similar injuries on the offender.[78] This strict equivalence is not characteristic of resentment as such.[79] There is undoubtedly a certain proportion between the pain-stimulus and the reaction; other things being equal, resentment increases in intensity along with the pain by which it is excited. The more a person feels offended, the greater is his desire to retaliate by inflicting counter-pain, and the greater is the pain which he desires to inflict. But resentment involves no accurate balancing of suffering against suffering, hence there may be a crying disproportion between the act of revenge and the injury evoking it.[80] As Sir Thomas Browne observes, a revengeful mind "holds no rule in retaliations, requiring too often a head for a tooth, and the supreme revenge for trespasses, which a night's rest should obliterate."[81] If, then, the rule of {179} equivalence is not suggested by resentment itself, this rule must be due to other factors, which intermingle with resentment, and help, with it, to determine the action. One of these factors, I believe, is self-regarding pride, the desire to pull down the humiliating arrogance of the aggressor naturally suggesting the idea of paying him back in his own coin; and it seems probable that the natural disposition to imitate, especially in cases of sudden anger, acts in the same direction. But besides this qualitative equivalence between injury and retaliation, the _lex talionis_ requires, in a rough way, quantitative equivalence, and this demand has no doubt a social origin. If the offender is a person with whose feelings men are ready to sympathise, their sympathy will keep the desire to see him suffer within certain limits; and if, under ordinary circumstances, they tend to sympathise equally with both parties, the injurer and the person injured, and, in consequence, confer upon these equal rights, they will demand a retaliation which is only equal in degree to the offence. By suffering a loss the offender compensates, as it were, for the loss which he has inflicted; and when equal regard is paid to his feelings and to those of his victim, it is deemed just that the loss