It's not an eye for an eye that's the problem. It's the fact that people don't learn from their mistakes. You have two eyes and if you lose one, wouldn't you do your uttmost to ensure that you kept the other one?
It's this kind of liberal minded woolley thinking that has allowed the evil of the world to thrive and prosper. Same thing as 'turning the other cheek' in christian religions, and just to put it into perspective ~ if that were truly the case then most of the christian countries in the world would have been over-run by people of other religions by now. Wars would never have been fought because everyone would have turned the other cheek or forgiven and forgotten. Utopia isn't a real place!