The Angelic Doctor Against the Errors of the Greeks - Part Two - Chapter 35

That he enjoys the same power conferred on Peter by Christ.

It is also shown that Peter is the Vicar of Christ and the Roman Pontiff is Peter’s successor enjoying the same power conferred on Peter by Christ. For the canon of the Council of Chalcedon says: “If any bishop is sentenced as guilty of infamy, he is free to appeal the sentence to the blessed bishop of old Rome, whom we have as Peter the rock of refuge, and to him alone, in the place of God, with unlimited power, is granted the authority to hear the appeal of a bishop accused of infamy in virtue of the keys given him by the Lord.” And further on: “And whatever has been decreed by him is to be held as from the vicar of the apostolic throne.” 

Likewise, Cyril, the Patriarch of Jerusalem, says, speaking in the person of Christ” “You for a while, but I without end will be fully and perfectly in sacrament and authority with all those whom I shall put in your place, just as I am with you.”  And Cyril of Alexandria in his Thesaurus says that the Apostles “in the Gospels and Epistles have affirmed in all their teaching that Peter and his Church are in the place of the Lord, granting him participation in every chapter and assembly, in every election and proclamation of doctrine.” And further on: “To him, that is, to Peter, all by divine ordinance bow the head and the rulers of the world obey him as the Lord himself.”  And Chrysostom, speaking in the person of Christ, says: “Feed my sheep (John 21:17), that is, in my place be in charge of your brethren.”