The primitive idea of justice is partly legalized revenge and partly expiation by sacrifice. It works out from both sides in the notion that two blacks make a white, and that when a wrong has been done, it should be paid for by an equivalent suffering. It seems to the Philistine majority a matter of course that this compensating suffering should be inflicted on the wrongdoer for the sake of its deterrent effect on other would-be wrongdoers; but a moment’s reflection will shew that this utilitarian application corrupts the whole transaction. For example, the shedding of blood cannot be balanced by the shedding of guilty blood. Sacrificing a criminal to propitiate God for the murder of one of his righteous servants is like sacrificing a mangy sheep or an ox with the rinderpest: it calls down divine wrath instead of appeasing it. In doing it we offer God as a sacrifice the gratification of our own revenge and the protection of our own lives without cost to ourselves; and cost to ourselves is the essence of sacrifice and expiation.
– George Bernard Shaw