What do you mean by "Justice"?
The two perspectives I'd like to pursue are; what is justice as a concept, and what does/could manifested justice look like?
Justice as a conceptAll concepts come from one of two places; they are descriptions of natural, physical phenomena (light for example) or they are abstractions, invented by humans out of logic, emotion or other non-physical sources. Justice as a concept is social and relativistic in nature - a monism is neither just nor unjust as there are no relative circumstances.
There are social Darwinists out there, though few of them realize they are. To these people, justice is what one finds in nature already. When the Cheetah eats the Gazelle, it is just because it is. When the poor person dies of hunger or disease, or when the robber baron hoards billions of dollars it is just because it is. So to a social Darwinist, justice is a description of nature.
I find this argument to be intellectually vacuous, as if what exists in physical nature were just, why would we have invented the concept of justice as opposed to the concept of reality. They'd be perfectly synonymous and therefore redundant. Of course, this cuts another way as well, which is that if the world were just, we would have no need for the word or concept. The need to describe justice shows that the world isn't just.
Most people don't answer in this way when you ask them. They generally describe justice as one of two abstract concepts; preservation of rights by members of a society, or correct application of social rules. These are seemingly very different ideas, depending on the rules of the society. I'll refer to the former as existential justice and the latter as legislative justice.
Legislative justice could be impalement for the crime of adultery as was the case in Apache society. Similarly, it could mean paying the bullet bill for the execution of your child in Soviet Russia. I think these are sufficient examples as to the inadequacy of the legislative justice argument. Social rules and laws can manifest justice, but their existence doesn't create justice.
We are left with existential justice. This is really problematic because the foundation for existential justice is inevitably a philosophy, and therefore not something that is universally shared. Put another way, existential justice is generally just another form of legislative justice, but for a set of rules that aren't the current law.
There is another octave of existential justice, and Jesus described it perfectly: Love your neighbor as yourself. Note that he didn't say "treat your neighbor as yourself". In other words don't judge others, love them. He said something like that too... So if justice is a social concept, and if any form of judgement or law is inadequate to some part of society, the only perfect justice is perfect love.
Therefore, this is my definition of what justice is: a perfect society.
The concept is only useful to point out injustice as nothing we currently experience is wholly just. Put another way, injustice is the delta between our conscience's projection of a perfect society and reality as it is. True justice is almost juxtaposed to the social darwinist or legislative forms, though these are obviously necessary precursors. Without "natural" justice, intelligence wouldn't have evolved. Without law, society wouldn't have formed. That's no reason to idolize them though. We must progress!
Justice ManifestedA perfect society would have no need, no harmful desire, no punishment, no contention, no shortcoming at all. Many have pointed out that this can be easily achieved by eliminating society and its constituents, but this is an adolescent and ego centric view not worth debating. Many others have pointed to models of imperfection, that contain much hate, pain, need, etc. and called them just. I find this to be a craven retreat from envisioning a truly just world. Jesus put the terms for perfect society in complete, if succinct terms. Buddha did the same. There is no retreat necessary to the brave, despite our distance from justice. Admitting defeat in forming a truly just society is to say that humanity is doomed.
The Buddhists rightly point out that one cannot force progress on others. To do so requires action, and this will create reaction. As modern science has shown, a butterfly's action in China can create a hurricane in Louisiana, so we should be cautious in acting with force as the unintended consequences can be vast. This leaves us with only one sure method to make progress towards a just society: spiritual development and setting a good example. This doesn't mean that we should not prevent people from asserting their will on others - we should enforce restraint to prevent injustice. Finding the right balance is very difficult.
Fast forwarding to a truly just society, we would need to have perfect and equal love. This can only be accomplished through spiritual work, and spiritual work can only be accomplished through physical efforts of thought and deed, and these are dependent on the less-just laws of nature, etc. So to me justice is an evolutionary path, not a juxtaposition of the just vs. the unjust or the good vs. the evil. If there is a good vs. evil or just vs. unjust in the final analysis, there must be a higher existence that is undifferentiated and therefore we are talking about demiurges of one form or another.
I'm sorry, but I can't help you with this. I'm still having a hard time understanding the difference between Justice and Revenge. Maybe someone else can help.
Not being able to discern a distinction between Justice and Revenge is truly grave. How about to give one their due? Equality.