I like tit-for-tat as a moral standard myself, in part because "[it] is [] a highly effective strategy in game theory for the iterated prisoner's dilemma":
http://en.wikipedia.org/wiki/Tit_for_tatI would not hit anybody on the head, but if somebody hits me on the head, I will hit that guy on the head as well. I will not do it harder, I will not do it twice, but I will hit the dude on the head.
This approach to interactions can be seen as a parallel to the
eye for an eye approach from Judeo-Christian-Islamic tradition, where the penalty for taking someone's eye is to lose one's own (cit from tit for tat wikipedia).
one thing is the self-defense, but...
what you say is an illusion for yourself but IS NOT TRUE,
because if someone hit you on the head, probably you are dead and you can't do anything.
So, is better to avoid all violent situations because you have not any control on when, where and what bad can happen to you.
Pro-Violence or not, it's the same.
I want to live without any paranoia.
And when i will die, i will die without having lived in paranoia or without doing any violence on nobody.
I know that this is only my opinion... an opinion from my very limited point of view.
regards