Judgement is ruled by Pluto, which also rules Scorpio.
Now tell me, which sign would be more prone to revenge, Scorpio or Libra?
Pluto (according to Ciro Marchetti) "...creates and destroys. There is a strong shadow side to Pluto that includes the underworld, obsession, coercion, and crime."
I'm completely clueless as to how you all see revenge in Justice! I must be missing something... Justice is blind, no mercy.
The concept of Justice (to me) is a part of Judgement.
Look at the utilitarianism ethical principal for example:
"There are two types of utilitarianism, act utilitarianism [Judgement] and rule utilitarianism [Justice]. In act utilitarianism, a person performs the acts that benefit the most people, regardless of personal feelings or the societal constraints such as laws. Rule utilitarianism, however, takes into account the law and is concerned with fairness. A rule utilitarian seeks to benefit the most people but through the fairest and most just means available. Therefore, added benefits of rule utilitarianism are that it values justice and includes beneficence at the same time (1,2)."
So, we're talking about revenge here (a negative of Judgement, in my opinion)- so the opposite of doing whatever act benefits the most people regardless of personal feelings or societal constraints.
Judgement = moral
Justice = principle
...and the two overlap. Morals are personal; principles are generally accepted morals.
Revenge is taking matters into one's own hands, seeking through passion to correct a "wrong" that was committed in the eyes of the one judging.
Justice is the part of Judgement that keeps our morals in check and everyone on a somewhat similar page. So, as much as you may want to strangle your ex-husband for sleeping with your best friend, you won't do it because you know you'll go to jail. Or, you know, you will do it because you feel strongly enough that you would be "right" to strangle your ex-husband for his terrible crime against you, and no amount of justice will stop you from righting that wrong for yourself. Revenge would overstep the boundaries of Justice in the sense that, if you strangle him, you don't feel or aren't thinking about his right to live... not fair in the generally accepted sense of the principle, but totally fair in your own eyes for what he did to you. There may not be an outwardly apparent consequence for your actions with Judgement, but there probably will be with Justice. Am I making sense?
When we have feelings, we are having a response to something. Having a fiery feeling of Judgement towards someone lends to a strongly passionate feeling of some kind. So, in my eyes, either the person has p*ssed you off to where you feel your deep sense of YOU has been personally trampled on, and you want them to pay, or in a positive sense- maybe this person evoked passion for your own life again within you, just by being in their presence. They make you feel like, "I want to LIVE again!"
That's why fire is so dangerous, and why I see revenge in Judgement, not Justice. But that's just my .02 cents anyway.