Gaius Marius Victorinus : Perhaps indeed he would at this point have kept silent about the sin that he says he reproved in Peter, for it was enough that Peter had been corrected by popular reproof and Paul's open accusation. But it is profitable and extremely requisite for this letter. He has two reasons for relating the incident. First, his own gospel was not reproved, and he himself, when he reproved Peter, heard no reproof from Peter. Next, this too, as I said, was extremely pertinent: it is because the Galatians thought that they needed to add to the principles of the gospel to obtain life … that this letter is being written to them. Hence it is very good to tell the story, because it is this very fault that was reproved by Paul in Peter and by the people also. In this way it follows that the Galatians too are sinning. — EPISTLE TO THE Galatians 1.2.12-13 Gaius Marius Victorinus : But in what way was Peter sinning? He had not adopted this ruse to bring in the Jews, meeting them on their own terms (which Paul himself had done and glories in having done, meeting the Jews on their own terms but for their profit). Rather, the sin of Peter lay in the fact that he withdrew, through fear of those who were of the circumcision. — EPISTLE TO THE Galatians 1.2.12-13 Irenaeus : But they themselves, while knowing the same God, continued in the ancient observances; so that even Peter, fearing also lest he might incur their reproof, although formerly eating with the Gentiles, because of the vision, and of the Spirit who had rested upon them, yet, when certain persons came from James, withdrew himself, and did not eat with them. And Paul said that Barnabas likewise did the same thing. Thus did the apostles, whom the Lord made witnesses of every action and of every doctrine-for upon all occasions do we find Peter, and James, and John present with Him-scrupulously act according to the dispensation of the Mosaic law, showing that it was from one and the same God; which they certainly never would have done, as I have already said, if they had learned from the Lord [that there existed] another Father besides Him who appointed the dispensation of the law. — Against Heresies Book III John Damascene : From those who came down from Jerusalem. "Because he was afraid of those from the circumcision." In other words, that he might not scandalize them, and might not suffer anything terrible on their account. Oecumenius : "from James." James, who is called the brother of Christ, served as bishop of Jerusalem. From him therefore those sent forth came who had believed from among the Jews, still observing the law. "he began to draw back and separate himself." From the association with the Gentiles, of course. And the phrase "fearing those" does not mean that he feared they might do him harm, but that he feared so as not to, having been scandalized, they might fall away from the faith. — Commentary on Galatians Tertullian : Paul, however, censures Peter for not walking straightforwardly according to the truth of the gospel. No doubt he blames him; but it was solely because of his inconsistency in the matter of "eating," which he varied according to the sort of persons (whom he associated with) "fearing them which were of the circumcision," but not on account of any perverse opinion touching another god. — Against Marcion Book V Tertullian : No doubt he blames him; but it was solely because of his inconsistency in the matter of "eating," which he varied according to the sort of persons (whom he associated with) "fearing them which were of the circumcision," but not on account of any perverse opinion touching another god. — Against Marcion Book V Theodoret of Cyrus : While active in Judea the holy apostles were forced to live according to the law on account of the weakness of the believers from Jewish backgrounds, for they held fast to the regulations of the law. But when they shifted to the cities of the Gentiles they had no need of such an accommodation but lived according to the freedom of the gospel. This is what the godly Peter did when he arrived in Antioch. He ate freely with the Gentiles. But when some of the Jews came he separated from the Gentiles, so that he might not give those who came from the Jews any pretext for doing harm. This is the meaning of "fearing those of the circumcision." For he who did not fear the whole host of the Jews did not succumb to fear of men, but he did not wish to furnish them with a pretext for scandal. — EPISTLE TO THE Galatians 2.12-13