What is Evil?

My last post got a few anti-libertarian comments - I can't really say much in reply to them. Either a person believes violence and aggression is wrong or not. Experience has shown that the latter leads to Hitlerite and Stalinist regimes which is something I clearly do not want. I don't consider people who believe in such violent methods as worth having discourse with - they just have to be ignored and stopped wherever possible. We must defend ourselves from barbarism, not engage in discussion and compromise with it. Cum recte vivis, ne cures verba malorum!
I also notice there is another important issue which must be discussed. What is freedom? Can there be freedom in regard to human interaction? Can we be free from bodily wants and needs? Can all compulsion be eliminated?
When answering these question we will get three groups of answers. Those three different answers are given by:
1) Libertarians/Right Anarchists who will say that only aggression is the enemy of freedom and all other voluntary transactions are legitimate.
2) Communists/Left Anarchists who will say that market transactions are compulsion and thus illegitimate.
3) Other people who have no moral convictions and are always saying either one or the other.
And here again we come back to the first question - is aggression the defining characteristic of good and evil? I would say that it is. With no aggression present I do not see how anyone can say any evil is taking place. In this I take the exact opposite stance from St.Augustine. Evil is not the absence of good, rather, good is the absence of evil. Now it must be pointed out that 90% of the world's population does not agree with this (I assume that only around 10% subscribe to answers #1 and #2). According to most people good and evil are some sort of metaphysical entities which actually exist out there somewhere and fly around possessing us. Hitler was possessed by the evil and Mother Teresa by the good. This is a very pragmatic view. Using this I can just say that anybody is good or anybody is evil depending on how I view them. There is no definite category of good or evil. It is all vague and made up. But I think that when I describe it this way everyone can see how stupid and superstitious this view really is.

People who espouse such opinions must be educated and shown how wrong they really are. Evil is the positive - it acts, and good is the negative - it does not act. Thus Friedrich Wilhelm Nietzsche was able to say: "He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss, the abyss gazes also into you." Fighting evil always entails commiting evil. And how can one fight fire with fire?