Reply to Objection 2: Justice is the same as rectitude, not essentially but causally; for it is a habit which rectifies the deed and the will.
Reply to Objection 3: The will may be called perpetual in two ways. First on the part of the will's act which endures for ever, and thus God's will alone is perpetual. Secondly on the part of the subject, because, to wit, a man wills to do a certain thing always. and this is a necessary condition of justice. For it does not satisfy the conditions of justice that one wish to observe justice in some particular matter for the time being, because one could scarcely find a man willing to act unjustly in every case; and it is requisite that one should have the will to observe justice at all times and in all cases.
Reply to Objection 4: Since "perpetual" does not imply perpetuity of the act of the will, it is not superfluous to add "constant": for while the "perpetual will" denotes the purpose of observing justice always, "constant" signifies a firm perseverance in this purpose.
Reply to Objection 5: A judge renders to each one what belongs to him, by way of command and direction, because a judge is the "personification of justice," and "the sovereign is its guardian" (Ethic. v, 4). On the other hand, the subjects render to each one what belongs to him, by way of execution.
Reply to Objection 6: Just as love of God includes love of our neighbor, as stated above (Q[25], A[1]), so too the service of God includes rendering to each one his due.
Whether justice is always towards one another?
Objection 1: It would seem that justice is not always towards another. For the Apostle says ( Rom. 3:22 ) that "the justice of God is by faith of Jesus Christ." Now faith does not concern the dealings of one man with another. Neither therefore does justice.
Objection 2: Further, according to Augustine (De Moribus Eccl. xv), "it belongs to justice that man should direct to the service of God his authority over the things that are subject to him." Now the sensitive appetite is subject to man, according to Gn. 4:7, where it is written: "The lust thereof," viz. of sin, "shall be under thee, and thou shalt have dominion over it." Therefore it belongs to justice to have dominion over one's own appetite: so that justice is towards oneself.
Objection 3: Further, the justice of God is eternal. But nothing else is co-eternal with God. Therefore justice is not essentially towards another.
Objection 4: Further, man's dealings with himself need to be rectified no less than his dealings with another. Now man's dealings are rectified by justice, according to Prov. 11:5, "The justice of the upright shall make his way prosperous." Therefore justice is about our dealings not only with others, but also with ourselves.
On the contrary, Tully says (De Officiis i, 7) that "the object of justice is to keep men together in society and mutual intercourse." Now this implies relationship of one man to another. Therefore justice is concerned only about our dealings with others.
I answer that, As stated above (Q[57], A[1]) since justice by its name implies equality, it denotes essentially relation to another, for a thing is equal, not to itself, but to another. And forasmuch as it belongs to justice to rectify human acts, as stated above (Q[57], A[1]; FS, Q[113], A[1]) this otherness which justice demands must needs be between beings capable of action. Now actions belong to supposits [*Cf. FP, Q[29], A[2]] and wholes and, properly speaking, not to parts and forms or powers, for we do not say properly that the hand strikes, but a man with his hand, nor that heat makes a thing hot, but fire by heat, although such expressions may be employed metaphorically. Hence, justice properly speaking demands a distinction of supposits, and consequently is only in one man towards another. Nevertheless in one and the same man we may speak metaphorically of his various principles of action such as the reason, the irascible, and the concupiscible, as though they were so many agents: so that metaphorically in one and the same man there is said to be justice in so far as the reason commands the irascible and concupiscible, and these obey reason; and in general in so far as to each part of man is ascribed what is becoming to it. Hence the Philosopher (Ethic. v, 11) calls this "metaphorical justice."
Reply to Objection 1: The justice which faith works in us, is that whereby the ungodly is justified it consists in the due coordination of the parts of the soul, as stated above (FS, Q[113], A[1]) where we were treating of the justification of the ungodly. Now this belongs to metaphorical justice, which may be found even in a man who lives all by himself.
This suffices for the Reply to the Second Objection.
Reply to Objection 3: God's justice is from eternity in respect of the eternal will and purpose (and it is chiefly in this that justice consists); although it is not eternal as regards its effect, since nothing is co-eternal with God.
Reply to Objection 4: Man's dealings with himself are sufficiently rectified by the rectification of the passions by the other moral virtues. But his dealings with others need a special rectification, not only in relation to the agent, but also in relation to the person to whom they are directed. Hence about such dealings there is a special virtue, and this is justice.
Whether justice is a virtue?
Objection 1: It would seem that justice is not a virtue. For it is written ( Lk. 17:10 ): "When you shall have done all these things that are commanded you, say: We are unprofitable servants; we have done that which we ought to do." Now it is not unprofitable to do a virtuous deed: for Ambrose says (De Officiis ii, 6): "We look to a profit that is estimated not by pecuniary gain but by the acquisition of godliness." Therefore to do what one ought to do, is not a virtuous deed. And yet it is an act of justice. Therefore justice is not a virtue.
Objection 2: Further, that which is done of necessity, is not meritorious. But to render to a man what belongs to him, as justice requires, is of necessity. Therefore it is not meritorious. Yet it is by virtuous actions that we gain merit. Therefore justice is not a virtue.
Objection 3: Further, every moral virtue is about matters of action. Now those things which are wrought externally are not things concerning behavior but concerning handicraft, according to the Philosopher (Metaph. ix) [*Didot ed., viii, 8]. Therefore since it belongs to justice to produce externally a deed that is just in itself, it seems that justice is not a moral virtue.
On the contrary, Gregory says (Moral. ii, 49) that "the entire structure of good works is built on four virtues," viz. temperance, prudence, fortitude and justice
I answer that, A human virtue is one "which renders a human act and man himself good" [*Ethic. ii, 6], and this can be applied to justice. For a man's act is made good through attaining the rule of reason, which is the rule whereby human acts are regulated. Hence, since justice regulates human operations, it is evident that it renders man's operations good, and, as Tully declares (De Officiis i, 7), good men are so called chiefly from their justice, wherefore, as he says again (De Officiis i, 7) "the luster of virtue appears above all in justice."
Reply to Objection 1: When a man does what he ought, he brings no gain to the person to whom he does what he ought, but only abstains from doing him a harm. He does however profit himself, in so far as he does what he ought, spontaneously and readily, and this is to act virtuously. Hence it is written ( Wis. 8:7 ) that Divine wisdom "teacheth temperance, and prudence, and justice, and fortitude, which are such things as men (i.e. virtuous men) can have nothing more profitable in life."
Reply to Objection 2: Necessity is twofold. One arises from "constraint," and this removes merit, since it runs counter to the will. The other arises from the obligation of a "command," or from the necessity of obtaining an end, when, to wit, a man is unable to achieve the end of virtue without doing some particular thing. The latter necessity does not remove merit, when a man does voluntarily that which is necessary in this way. It does however exclude the credit of supererogation, according to 1 Cor. 9:16, "If I preach the Gospel, it is no glory to me, for a necessity lieth upon me."
Reply to Objection 3: Justice is concerned about external things, not by making them, which pertains to art, but by using them in our dealings with other men.