More and more, I think "justice" is one of those words that mean whatever we want them to mean: for some, vengeance; for others, mercy; for still others, retribution or reparations, and so on. That's why discussions of justice tend to go around in circles, with each side claiming the others are not negotiating in good faith. 
Interestingly, the New Testament, largely written in anticipation of the Parousia, uses another rather nebulous term -- dikaiosune (righteousness) -- as what is required of believers. Look at all the fun we have trying to decide what that means.