On the contrary, It is written (Ps. 93:15): "Until justice be turned into judgment."
I answer that, Judgment properly denotes the act of a judge as such. Now a judge (judex) is so called because he asserts the right (jus dicens) and right is the object of justice, as stated above (Q. 57, A. 1). Consequently the original meaning of the word "judgment" is a statement or decision of the just or right. Now to decide rightly about virtuous deeds proceeds, properly speaking, from the virtuous habit; thus a chaste person decides rightly about matters relating to chastity. Therefore judgment, which denotes a right decision about what is just, belongs properly to justice. For this reason the Philosopher says (Ethic. v, 4) that "men have recourse to a judge as to one who is the personification of justice."
Reply Obj. 1: The word "judgment," from its original meaning of a right decision about what is just, has been extended to signify a right decision in any matter whether speculative or practical. Now a right judgment in any matter requires two things. The first is the virtue itself that pronounces judgment: and in this way, judgment is an act of reason, because it belongs to the reason to pronounce or define. The other is the disposition of the one who judges, on which depends his aptness for judging aright. In this way, in matters of justice, judgment proceeds from justice, even as in matters of fortitude, it proceeds from fortitude. Accordingly judgment is an act of justice in so far as justice inclines one to judge aright, and of prudence in so far as prudence pronounces judgment: wherefore synesis which belongs to prudence is said to "judge rightly," as stated above (Q. 51, A. 3).
Reply Obj. 2: The spiritual man, by reason of the habit of charity, has an inclination to judge aright of all things according to the Divine rules; and it is in conformity with these that he pronounces judgment through the gift of wisdom: even as the just man pronounces judgment through the virtue of prudence conformably with the ruling of the law.
Reply Obj. 3: The other virtues regulate man in himself, whereas justice regulates man in his dealings with others, as shown above (Q. 58, A. 2). Now man is master in things concerning himself, but not in matters relating to others. Consequently where the other virtues are in question, there is no need for judgment other than that of a virtuous man, taking judgment in its broader sense, as explained above (ad 1). But in matters of justice, there is further need for the judgment of a superior, who is "able to reprove both, and to put his hand between both" [*Job 9:33]. Hence judgment belongs more specifically to justice than to any other virtue.
Reply Obj. 4: Justice is in the sovereign as a master-virtue [*Cf. Q. 58, A. 6], commanding and prescribing what is just; while it is in the subjects as an executive and administrative virtue. Hence judgment, which denotes a decision of what is just, belongs to justice, considered as existing chiefly in one who has authority. _______________________
SECOND ARTICLE [II-II, Q. 60, Art. 2]
Whether It Is Lawful to Judge?
Objection 1: It would seem unlawful to judge. For nothing is punished except what is unlawful. Now those who judge are threatened with punishment, which those who judge not will escape, according to Matt. 7:1, "Judge not, and ye shall not be judged." Therefore it is unlawful to judge.
Obj. 2: Further, it is written (Rom. 14:4): "Who art thou that judgest another man's servant[?] To his own lord he standeth or falleth." Now God is the Lord of all. Therefore to no man is it lawful to judge.