The Lex Talionis (‘an eye for an eye, a tooth for a tooth …’ ) was introduced by Hammurabi of Babylon, as a measure to control private vengeance and concentrate punishment in the hands of legitimate authority. It also carried the message that punishment should be proportionate to the crime, a principle that was pressed by progressive thinkers in later ages, such as Montesquieu. As the law was formulated, an offence committed merited an equivalent punishment: one eye for an eye, not two. Over time the Lex became the standard-bearer of backward-looking retributivism, which carries the idea that offenders deserve to be punished simply because of the offence they have committed. As such, it was an obstacle in the way of any burgeoning abolitionist thought, in particular because it prescribed ‘a life for a life’. The abolitionist Giuseppe Pelli attacked the Lex head-on. In doing so he drew on the diverse critiques of the Lex of a succession of earlier (non-abolitionist) thinkers. The Lex Talionis has staying power. It embodies a basic human conviction that retaliation is due for injuries suffered. As such, it is outside the law; it will coexist with, and survive, any legal environment.