Lex talionis
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
The law of retaliation ; which requires the infliction uppn a wrongdoer of the same injury which he has caused to another. Expressed in the Mosaic law by the formula, "an eye for an eye; a tooth for a tooth," etc. In modem international law, the term describes the rule by which one state may inflict upon the citizens of another state death, imprisonment, or other hardship, in retaliation for similar injuries imposed upon its own citizens.