Justice is one of the four cardinal virtues in classical European philosophy and Roman Catholicism. It is the moderation or mean between selfishness and selflessness - between having more and having less than one's fair share.
Justice is closely related, in Christianity, to the practice of Charity (virtue) because it regulates the relationships with others. It is a cardinal virtue, which is to say that it is "pivotal", because it regulates all such relationships, and is sometimes deemed the most important of the cardinal virtues.
According to Aristotle, "Justice consists in a certain equality by which the just and definite claim of another, neither more nor less, is satisfied."
This is equal insofar as each one receives what he is entitled to, but may be unequal insofar as different people may have different rights: two children have different rights from a certain adult if that adult is the parent of one of them and not of the other. Aristotle developed the idea of equity to cover irregular cases so that "the ordinance is framed to fit the circumstances".
The just man, often mentioned in the Sacred Scriptures, is distinguished by habitual right thinking and the uprightness of his conduct toward his neighbor. In Colossians 4:1 St. Paul counsels "Masters, treat your slaves justly and fairly, realizing that you too have a Master in heaven."
In Christian moral theology, Justice is a quality or habit which perfects the will and inclines it to render to each and to all what belongs to them. The object of the virtue of justice is the other person's rights, whether natural or bestowed by Church or State. Justice requires that all persons should be left in the free enjoyment of all their rights. The rights which belong to every human being inasmuch as he is a person are absolute and inalienable.
In Aristotle's wake,Thomas Aquinas developed a theory of proportional reciprocity, whereby the just man renders to each and all what is due to them in due proportion: what it is their moral and legal rights to do, possess, or exact. Justice toward God is called the "virtue of religion".
With the late modern rise in interest in virtue ethics, a new interest in articulating the virtue of justice has emerged. John Rawls saw justice as the typical virtue of the institution; Irene van Staveren saw it as that of the state, marked by such indicators as votes, legitimacy, public fairness and distributive rules.
Freudians consider that in the unconscious the image of the Father embodies a stern but fair justice;Jungians similarly see the archetype of the King as representing the right ordering of society.
Wallace Stevens rejected what he called "galled Justicia/Trained to poise the tables of the law" as part of the obsolete images of the past, and favoured instead the modernist seeking out of new ruling images - new "sovereigns of the soul".