…makes the whole world blind”, so said a well known guy. How would it work?
Say there are two people in the world who each have 20/20 visions in both eyes. For some reason — and it's not important what it is and without loss of generality, as they say in mathematics, can be assumed anything — first man punctures second man’s one eye. Why one eye and not both, you may legitimately ask? But you wouldn’t have been paying attention to quote then, would you? So if well known guy is correct then second man will take revenge by puncturing first’s one eye. That will leave world half-blind, but that’s not the idea really. So, of course, first will take vendetta by blinding second one completely by hurting his second eye too. Now, if world were to be blind, as predicted, then second man must blind first one too. However, and this is where we must pause and think, when second is completely blind and first is half-blind, what reasonable chance second man has of chasing, catching and blinding first one?
Clearly the well known guy didn’t think it through in his hurry to get quotable quote out. In reality, an eye for an eye makes half the world blind and half the world half-blind, or, whole world three-quarter blind, if we average out.