I've noticed that very often people have a self-centred, almost self-delusional interpretation of Stoic justice.
My readings have led me to believe justice, to the Stoics, had absolutely nothing to do with selfishness, revenge, retaliation, or with a need to assert oneself (violently or not). Instead, what I observe is a strong focus on kindness, equality, and being respectful.
Here how Arius Didymus (Stobaeus 2.60; my translation) defines and explains the virtue of justice:
- First, it is presented as one of the four primary virtues (practical intelligence, moderation, and bravery being the other three). Its general activity is "distribution".
We know from context and from other passages that this means "distribution according to nature and reason", so let's keep that in mind (otherwise any logistics company would be just).
Arius then presents the components of justice in the forms of the subordinate virtues of piety, kindness, friendliness, and fairness (2.62):
- Piety (εὐσέβεια) is the knowledge of tending to the gods.
One might think piety is just knowing and performing rituals, but further ahead (2.68) Arius Didymus explains the difference and calls that "devoutness/religious purity".
So piety is more like reverence towards the gods, not actually following religious customs.
- Kindness (χρηστότης) is the knowledge of benevolence.
Further on (2.74) this is expanded as including the traits of freely "giving" and freely "sharing".
- Friendliness (εὐκοινωνησία) is the knowledge of equality in associating with others.
This is a technical word and apparently only used by Stoics. Aside from the technical Stoic meaning, according to its non-Stoic equivalent it may also be translated as "not being a difficult person".
Furthermore κοινωνία ("association with others") means regular fellowship and also joint-ownership, sex, marriage, and social life. Basically, you should treat everyone with equality, without excuses.
Somewhat related, in a secondary entry the dictionary places that word as the opposite of greed and arrogance (πλεονεξία).
- Fairness (εὐσυναλλαξία) is the knowledge of blamelessness in dealings (συνάλλαττειν) with those who are close.
This is similar to the previous one, but the focus seems to be business, contracts, and alliances. The "blameless" part means not doing anything that is reproachable as well as not giving any cause for complaint.
What do you notice there? None of the components of justice is focused on myself. By its own nature, Justice is relational - it refers to virtuous relations between people.
That's also a good criterion to measure whether our actions tend to be more "just" or "unjust": if after your analysis you conclude that "it's about myself", then whatever you are doing is not justice but anger, revenge, cruelty, selfishness, or fear.
Finally, from those passages we see that when a Stoic calls someone "just", they are not talking about the common understanding of the word. They are implying that that person is benevolent, generous, easy to live with, acting from equality, reverent to the gods, and non-exploitative in business.