My try to answer what justice is:
Word Justice - Definition
After Oxford English Dictionary:
Oxfor English Dicitionary - Justice definition
Word "justice" is most frequently used in context of this definition (per OED - Oxfor English Dictionary):
III.
The quality of being just. Cf.
justness n.
- III.7.
The quality of being just or right, as a human or divine attribute; moral uprightness; just behaviour or dealing as a concept or principle (one of the four cardinal virtues: cf.
cardinal adj. I.1); the exhibition of this quality or principle in action; integrity, rectitude.
Ethymology: comes from Latin ius = law
This definition matches the frequency of word justice in different contexts for which I used Google Books Ngram Viewer:
https://books.google.com/ngrams/graph?content=justice+AND+social&year_start=1980&year_end=2022&case_insensitive=true&corpus=en&smoothing=3
searched: justice AND social, justice AND religion, justice AND philosophy, justice AND law, justice AND judicial.
Most frequent from those 5 was justice AND social.
Ulpian's definition:
the constant and perpetual will to render to each his due
Elegant definition but missing some important part which maybe in Justinian times were understood as obvious: due because of what?
To me it seems that definition and etymology of this word directs my mind to more general category from which justice is derived which is category of law.
So justice is on lower logical level than law.
Justice is a function of law.
Justice is in relation to law ... maybe like medicine to health. Correct me if it is wrong reasoning.
Justice has balancing function.
So what is just or unjust may be defined when we know the law.
Do I know the law?
Here more questions than answers to me is coming.
For example: I do not know if I may so easily infer general law of free will from existence of free will in me? Without necessity to support my reason with C's material?
I would like to believe that probably yes :) otherwise we all would be dependent always for understanding of the world on external party.
Question: am I able to figure out all necessary things about what I need to pass the lesson here and now without external help?
Reality of my life shows that no. That at least if not other density it is a lot of other human beings that help to understand who I am, where I am, why and for what.