Eye for an eye, a tooth for a tooth.
~ Biblical Proverb [19575]

The ancient principle of 'lex talionis,' is one of the most controversial and misunderstood proverbs in history. Some people interpret the words literally, others metaphorically, while still others, with disgust. The idea that the punishment should fit the crime has long been established as a good rule of law. Whereas the idea of literally maiming someone in revenge, is unacceptable in advanced civilizations. Contrast with:

"An-eye-for-an-eye-for-an-eye-for-an-eye ...
ends in making everybody blind."

~ Mohandas Gandhi

"The old law of an eye for an eye leaves everyone blind."
~ Martin Luther King, Jr.

"You have heard that it was said, 'An eye for an eye and a tooth for a tooth.' But I say to you, Do not resist the one who is evil. If anyone slaps you on the right cheek, turn to him the other also."
~ Jesus of Nazareth

For more information see Wikipedia's entry.