After Aristotle has discussed the virtues that pertain to the passions as they relate to reason, he discusses the virtue of justice, which will be about relation between the agent and another. The question of justice to oneself is discussed at points throughout the Book, and is definitively answered in the last section.
I use here the division according to the lectures in the commentary by St. Thomas Aquinas:
Aquinas points out first that “concerning justice [Aristotle] proposes for consideration three differences existing between justice an the previously mentioned virtues”…the previous “are concerned with the passions…we took the mean and not the thing…Each of the afore-mentioned virtues is a mean between two vices, but justice is not a mean between two vices.”
Will, and not the senses more directly, is the proper subject of justice; justice is defined in the Catechism of the Catholic Church as “the moral virtue that consists in the constant and firm will to give their due to God and neighbor.” So justice is a mean in one way, in that it gives what is do, and not more or less (when we are speaking of strict justice). But true justice is found first in the will, and only then in the object, to which the will is conforming and striving. Therefore, an event can occur that is objectively unjust, but it may not be an unjust act on the part of the agent, who wills to be just, but mistakenly, and thus commits an objective unjustice.
Legal justice (885-926)
He says first that justice itself is a certain perfect virtue not in terms of itself but in relation to another. Legal justice is justice as relates to the community at large, that is, primarily, the polis or state.
Aristotle then discusses distributive justice and commutative justice. The first of these deals with what the state or community owes the individual, and this in a proportionate manner, meaning it is based on what the individual contributes to society and perhaps to his rank or position. So a general may deserve more honor and a bigger house from the state. However, when it comes to communitive justice, this is not necessarily so. The general and the peasant will generally pay the same price for a new set of Reeboks. Because of this more strict equality of communitive justice, economic issues get discussed by Aristotle, to include the coming into being and use of money as a standard of trade.
We are reminded, frequently throughout Aristotle’s account of the virtues, but seemingly more often during his treatment of justice, that it is reason and not man that should truly govern man. In legal justice especially, but in all three aspects of justice, man is the reasoner, but it is reason that is law, and not man arbitrarily.
Its object (1078-1088)
St. Thomas clearly states the overall topic of this part of the treatise: ‘In Greek epiiches is understood as what is reasonable or becoming; it is derived from epi meaning “above” and ikos meaning “obedient,” because by equity a person is obedient in a higher way when he follows the intention of the legislator where the words of the law differ from it.’
Today, we often discuss keeping the intention of the law versus the letter, and often find that there arise cases where keeping the letter of the law is in direct opposition to the intention of the creator of the law in its original and universal conception.
Its subject (1089) and habit (1090)
The virtuous man is not a zealous enforcer of the law for vengeance’ sake, but rather, to make the offender better and safeguard the community. The habit, then, of equity is not a virtue distinct from justice, but a species thereof.
Aristotle lastly revisits a topic he has touched upon several times throughout the treatise on justice, once again affirming that, despite the arguments that appear to the contrary, a man cannot really do injustice to himself, and this because to do injustice requires it be against one’s will, and one so to commit injustice against oneself implies a contradiction.
Justice and Equity
The difference in justice and equity is certainly a debated point in Christian theology, and no more is it a more pressing and divisive topic than when concerning election. The main point seems to be this: that God, in justice, could let us all remain unsaved (not justified) and yet, He, by mercy, wills to save some. This salvation of only some is, then, certainly just, but most certainly not equitable.
St. Thomas states in his commentary that “The reason why not everything can be determined according to the law is that the law cannot possibly be framed to meet some rare particular incidents, since all cases of this kind cannot be foreseen by man. On account of this, after the enactment of the law, a decision of the judges is required by which the universal statement of the law is applied to a particular matter. Because the material of human acts is indeterminate, it follows that their norm, which is the law, must be indeterminate in the sense that it is not absolutely rigid.”
While I certainly do not have the space here to propose how this may give insight into the justice/mercy question and the will of God “that all be saved” is also in conformity with the fact that “few enter” and are saved (combined with God as universal first mover but creatures as true causes), I think that the above comment can indeed be a point of reflection on the mystery of God’s justice and election.