Today, keeping in mind recent events within the Church, we offer a somewhat brief text from Cardinal Cajetan’s celebrated commentary on the Summa theologiæ of St. Thomas, IIaIIæ, q. 33, a. 4, Whether a man is bound to correct his prelate? Cajetan mostly comments on St. Thomas’ response to the second objection, which has to do with St. Paul withstanding St. Peter to the face in Galatians 2:11. We shall give the text of objection 2 and St. Thomas’ response, followed by the comment of Cajetan.
Obj. 2: Further, a gloss on Gal. 2:11, “I withstood him to the face,” adds: “as an equal.” Therefore, since a subject is not equal to his prelate, he ought not to correct him.
Ad 2: To withstand anyone in public exceeds the mode of fraternal correction, and so Paul would not have withstood Peter then, unless he were in some way his equal as regards the defense of the faith. But one who is not an equal can reprove privately and respectfully. Hence the Apostle in writing to the Colossians (4:17) tells them to admonish their prelate: “Say to Archippus: Fulfil thy ministry [*Vulg.: ‘Take heed to the ministry which thou hast received in the Lord, that thou fulfil it.’ Cf. 2 Tim. 4:5].” It must be observed, however, that if the faith were endangered, a subject ought to rebuke his prelate even publicly. Hence Paul, who was Peter’s subject, rebuked him in public, on account of the imminent danger of scandal concerning faith, and, as the gloss of Augustine says on Gal. 2:11, “Peter gave an example to superiors, that if at any time they should happen to stray from the straight path, they should not disdain to be reproved by their subjects.”
Commentary of Cardinal Cajetan
I. In the fourth article, in response to the second objection, there is a great doubt: how Paul was equal to Peter as regards the defense of the faith, since Peter was the sole universal pastor, being superior to all as the head to the members because of the office of the papacy, even as regards the defense of the faith.
To this, it is said that, regarding the defense of the faith, Paul was equal to Peter executively. Wherefore also in the text of St. Thomas, it is said in some way: as if to say, that not simply in the defense of the faith, but in some way in this was he equal. But this parity signifies the universal care in both, of defending the faith had from the Lord Jesus Christ. The supreme authority is consistent with this equality, because the office is in Peter alone of defending the faith. Just as if the Pope were to commit episcopal authority in some diocese to an archpriest, the archpriest would be equal to a bishop on account of the delegated power for executing [duties], but not from an office.
II. In the same response to the second objection, note that, since the apostolic teaching is proposed to the Church not by word alone, but by deed; from the deed of Paul, we are taught that, where there is danger to the faith (not lifeless faith but living faith) in some church—and there is hope of assisting in this danger not through secret admonition, but only through this—the prelates should be charged publicly by the subjects, as the prelates err publicly. Indeed, the deed of Peter was not so great that it would have the nature even of active scandal; as the Author says below in the question on scandal. And danger to charity is danger to life: because faith without works is dead. And again, the Church’s whole study is to bring forth, nourish, and protect living faith: and the part which remains is to be bound into bundles to burn. For this reason, Paul, charging Peter because of the danger to the salvation of those believing, and not suffering so small a sin (yet scandalous still), taught others how bold they ought to show themselves in accusing the sins (yet with words) of their prelates who are scandalizing the Church and drawing others to damnation by their example. And to this are held princes both of the Church and of the world, when the Pope scandalizes the Church and, reverently reminded of his office, comes not to his senses. For and in fact, it is probable that he will respect princes who accuse in public, although he scorns the good of the subjects; and if he does not become good, he will at least not scandalize others. For those who are able to provide help are much more obliged to this than to destroying those who are led to corporeal death. For they ought to set up a wall for the house of Israel. He who shall see his brother in need, and shall shut up his bowels from him: how doth the charity of God abide in him?
 James 2:26.
 Cf. Augustine, De Trinitate, lib. XIV, cap. 1.
 Matthew 13:30.
 Ezechiel 13:5.
 1 John 3:17.