of the Council of Chalcedon on the same matter is present to the minds of all: "Peter has spoken through Leo,"[1] to which the voice of the Third Council of Constantinople responds as an echo: "The chief Prince of the Apostles was fighting on our side: for we have had as our ally his follower and the successor to his see: and the paper and the ink were seen, and Peter spoke through Agatho."[2]
In the formula of Catholic faith drawn up and proposed by Hormisdas, which was subscribed at the beginning of the sixth century in the great Eighth Council by the Emperor Justinian, by Epiphanius, John and Menna, the Patriarchs, this same is declared with great weight and solemnity. "For,the pronouncement of Our Lord Jesus Christ saying: 'Thou art Peter, and upon this rock I will build My Church,' etc., cannot be passed over. What is said is proved by the result, because Catholic faith., has, always been preserved without stain in the Apostolic See."[3] We have no wish to quote every available declaration; but it is well to recall the formula of faith which Michael Paleologus professed in the Second Council of Lyons: "The same holy Roman Church possesses the sovereign and plenary primacy and authority over the whole Catholic Church, which, truly and humbly, it acknowledges to have received together with the plenitude of power from the Lord Himself, in the person of St. Peter, the Prince or Head of the Apostles, of whom the Roman Pontiff is the successor. And as it is bound to defend the truth of faith beyond all others, so also if any question should arise concerning the faith it must be determined by its judgment.",[4]
But if the authority of Peter and his successors is plenary and supreme, it is not to be regarded as the sole authority. For He who made Peter the foundation of the Church also chose twelve, whom He called apostles;[5] and
