lex talionis (leks tal-ee-oh-nis). [Law Latin] The law of retaliation, under which punishment should be in kind — an eye for an eye, a tooth for a tooth, and so on — but no more. — Also termed eye for an eye; jus talionis; principle of retribution.

“Kant, for example, expresses the opinion that punishment cannot rightly be inflicted for the sake of any benefit to be derived from it either by the criminal himself or by society, and that the sole and sufficient reason and justification of it lies in the fact that evil has been done by him who suffers it. Consistently with this view, he derives the measure of punishment, not from any elaborate considerations as to the amount needed for the repression of crime, but from the simple principle of lex talionis: ‘Thine eye shall not pity; but life shall go for life, eye for eye, tooth for tooth, hand for hand, foot for foot’ [Deuteronomy, xix 21]. No such principle, indeed, is capable of literal interpretation; but subject to metaphorical and symbolical applications it is in Kant’s view the guiding rule of the ideal scheme of criminal justice.” John Salmond, Jurisprudence 118 (Glanville L. Williams ed., 10th ed. 1947).

“But if the old form of the lex talionis, an eye for an eye or a tooth for a tooth, sounds too barbaric today, may we not reformulate the retributive theory and put it thus: Everyone is to be punished alike in proportion to the gravity of his offense or to the extent to which he has made others suffer?” Morris R. Cohen, Reason and Law 53 (1961).

[Blacks Law 8th]