Old Testament Correction

My fingers got a little ahead of my brain last night. Thanks to Rob for catching it. An eye for an eye is indeed an Old Testament reading. Jesus references it in his Sermon on the Mount where he says, "You have heard it said...." meaning "The Old Testament says..." So, in effect he is saying, "The Old Testament says, 'an eye for an eye and a tooth for a tooth' but I tell you not to resist. If someone slaps you on your right cheek, turn and offer the other cheek." He then continues, "If anyone wants to sue you and take away your shirt, let him have your coat too. If someone compels you to go one mile, go with him two." The interpretation of this within the Christian community is varied with most of the discussion centering on pacifism. Main stream folks would say He's not talking about what our culture likes to call "self-defense." With uses of the words "slap" and "sue" and "compel", He seems to be referring to non-violent events. The idea being that if relatively minor or non-violent altercations could be dealt with in this way by each of us, they would no doubt never escalate into fights and wars. Though this is all very fascinating, my point was simply that some people have no trouble judging what they like and don't like from the Bible. I'm simply wondering what they use for their straight line to judge a crooked line.