an eye for an eye, a tooth for a tooth
Many people misunderstand these words. It was a law invented by Moses, when the people travelled out of Egypt in to the desert. Moses was their leader, and as such he was compelled to judge people who argued or fought with each other. This law was made to make clear that people who were abused had the right to revenge, but only with the same abuse. This prevented minor incidents to become big wars. An eye for an eye means something like: if your neighbour speaks bad of you, you are allowed to speak bad things about him too, but you are certainly not allowed to knock him down.... Because of this law the people succeeded to travel through the desert without hurting each other too much. They were stateless, and had to invent their own way of law and order. The ten commandments are also a result of this proces. A sort of mini-law, given by God, to survive the stateless period. They are so elementary that even up to today people live up to these rules, or at least try to.
If you know what these words really mean (they are often used to justify the very thing they tried to prevent), they are in fact very wise, and given the situation certainly effective....