Bertrand Russell on Revenge

“...revenge. ...This reaction is still admired by most people, when the injury is great, and such as to arouse moral horror in disinterested people. Nor can it be wholly condemned, for it is one of the forces generating punishment, and punishment is something necessary. Moreover, from the point of view of mental health, the impulse to revenge is likely to be so strong that, if allowed no outlet, a man's whole outlook on life may become distorted and more or less insane.”

“...revenge is a very dangerous motive.... it allows a man to be the judge in his own case, which is exactly what the law tries to prevent. Moreover it is usually an excessive motive; it seeks to inflict more punishment than is desirable. Torture, for example, should not be punished by torture, but the man maddened by lust for vengeance will think a painless death too good for the object of his hate. Moreover, and it is here that Spinoza is in the right - a life dominated by single passion is a narrow life, incompatible with every kind of wisdom. Revenge as such is therefore not the best reaction to injury.”