I tend to disagree with your analogy to salvery and the like, because despite the desire to have a peacefull world, we are simply never going to give up on selfishness. That is the way we are wired, its in our genes (so to speak). Both from an evolutionary standpoint as well as from a biblical one (for once they agree here ). Humans would always choose for themselves and never for someone else and if we do we essentially do so to ease our conscience and boast about it to others.
Slavery is in a sence in our genes as well because we want to dominate others, but the weakness of that was that slavery in itself is something visible and therefor something defeatable (if only in potention). Selfishness is invisible and therefor undefeatable. In a sence it is like weed, it always comes back.

Now you may dream about people who are no longer selfish (and basically I share the same dream), but how? Education? Isn't Amerika one of the best countries in the world when it comes to education? Yet the whole economic crisis is to blame on selfishness of men. Mostly in the USA and other highly educated natoins.
Both world wars were started (I'm over simplifying now) by Germany what was the highest educated country in the world at that time, yet they all became selfish and only cared about their own nation and inside they were still selfish and tried to reach to the top of the ladder.
Not education, what about upbringing. Remember the hippi cults? New Age spiritualism and the like? Remember even idealistic christian movements? They bring up their children and what happens? Clearly not all of them follow the example of their parents. Even many first-generation communities fall apart due to strife, internal competition for power and selfishness (you can read the letters of Paul to the Corinthians in the bible for example where these things happened whitin a few years after they were founded).

My point is not simply "it never has been, ergo it never will be", but it goes much deeper. It is in our nature, in our genes, our bones. We simply are selfish and will never be cured of that disease.

One last remark and that is concerning the nature of your question. You asked "what is justice?", I took that in a neo-neo platonic sence, yet you seem to take it in a pragmatic sence. Is that correct?



Once you remember let me know