A reader writes:

I just read your article about Infallibility. Of course, you didn’t write the article to address my specific question, so it would be unfair of me to expect too much from it—but I get the impression from your article that it all comes down to Peter being the Rock of the one and only institutional Church. But it appears that this phrase, while loosely grounded in Matthew 16, is really an article of faith that must be accepted. Once you accept the idea that Peter (and every one of his successors) leads the one and only institutional Church, then the Catholic Church is the place to be. And I would agree with you, if I give you that article of faith.

Do you have any other reasons to believe this infallible succession other than the Passage in Matthew 16? This seems to be at the heart of the Catholic church’s ability to call itself the one and only church.

It’s true that infallibility is an article of the Faith. But it comes down, not to Peter, but to the nature of the Church as the body of Christ guided by the Spirit through history.  he infallibility of the Petrine office is an extension of the infallibility of the Church. And the infallibility of the Church comes from the fact that the Holy Spirit and no mere mortal human being is the soul of the Church. It rests on the promise of Jesus to be with the Church always (Matthew 28:20) and, by his Spirit, to guide it into all truth (John 16:13). Apostolic succession (including the succession of the Petrine office) is a fact already seen in Scripture, with bishops appointed by apostles to guard the deposit of faith. (That is the fact presupposed by the epistles to Timothy and Titus and recorded in passing in Acts 14:23.) The phrase “institutional Church” is foreign to the New Testament, as is the notion that there is an “institutional Church” that is somehow distinct from some real and invisible Church. There is just “the Church” in the New Testament: the body of Christ joined to the Head and the members in baptism and in union with the apostles and the bishops: “There is one body and one Spirit, just as you were called to the one hope that belongs to your call, one Lord, one faith, one baptism, one God and Father of us all, who is above all and through all and in all” (Ephesians 4:4-5). The function of the bishop is to teach, govern and sanctify the Church as both the conservator and developer of the Tradition. I can’t recall if I’ve sent you this link, but it might help a bit.
 
So: The Pope is not the CEO of Catholicism, Inc. with other bishops acting as middle management. He is the Servant of the Servants of God. The tradition he conserves is the Tradition the Church conserves. As Hans urs von Balthasar put it, truth is symphonic. The roots of his office are found, not in medieval imperialism, but in the Old Testament: specifically Isaiah 22:15-25.

Thus says the Lord GOD of hosts, “Come, go to this steward, to Shebna, who is over the household, and say to him: What have you to do here and whom have you here, that you have hewn here a tomb for yourself, you who hew a tomb on the height, and carve a habitation for yourself in the rock? Behold, the LORD will hurl you away violently, O you strong man. He will seize firm hold on you, and whirl you round and round, and throw you like a ball into a wide land; there you shall die, and there shall be your splendid chariots, you shame of your master’s house. I will thrust you from your office, and you will be cast down from your station. In that day I will call my servant Eliakim the son of Hilkiah, and I will clothe him with your robe, and will bind your girdle on him, and will commit your authority to his hand; and he shall be a father to the inhabitants of Jerusalem and to the house of Judah. * And I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open. And I will fasten him like a peg in a sure place, and he will become a throne of honor to his father’s house. 2nd they will hang on him the whole weight of his father’s house, the offspring and issue, every small vessel, from the cups to all the flagons. In that day, says the LORD of hosts, the peg that was fastened in a sure place will give way; and it will be cut down and fall, and the burden that was upon it will be cut off, for the LORD has spoken.”

This is the OT background for the prophesy of the “keys” committed to Peter (or “Kefa” as he was actually called by Jesus in Aramaic, which is why Paul and John call him “Cephas”). Shebna was a sort of prime minister or major domo, acting with the authority of the Davidic king. He abused his authority and so the “keys of the kingdom” were given to Eliakim. In the same way, the keys are taken from Caiaphas and given (note the pun) to “Kefa” with the promise that the gates of hell shall not stand against the Petrine office. The promise is not that Peter will be without sin, but that he will not pervert the teaching. As to the succession, you can read the record of Petrine succession in any decent history of the papacy. It’s not without a certain amount of hiccups (particularly in the 14th century), but the remarkable thing is that even dedicated enemies of the papacy have such sparse ammunition for charging it with altering the tradition.

Bottom line: Papal succession is a matter of history. Papal infallibility is a matter of faith. It can’t be proven from reason any more than the Trinity can. But all objections to it can be refuted with reason just as objections to the Trinity can.