I noticed an older article, titled Can Christ & Peter Both be “Rocks”?, on Dave Armstrong’s excellent blog Biblical Evidence for Catholicism. I don’t disagree with much that Dave says in that article; rather, my position adds to what he says. Read his article first.

It is Catholic dogma that Peter is the Rock on which the Church is founded. This is the ancient and constant teaching of the Church under the ordinary universal Magisterium and is confirmed by Vatican I, Pastor Aeternus, chap. 1 and 2. This teaching is the constant interpretation of the words of Christ:

[Matthew]
{16:15} Jesus said to them, “But who do you say that I am?”
{16:16} Simon Peter responded by saying, “You are the Christ, the Son of the living God.”
{16:17} And in response, Jesus said to him: “Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my Father, who is in heaven.
{16:18} And I say to you, that you are Peter, and upon this rock I will build my Church, and the gates of Hell shall not prevail against it.
{16:19} And I will give you the keys of the kingdom of heaven. And whatever you shall bind on earth shall be bound, even in heaven. And whatever you shall release on earth shall be released, even in heaven.”

The Church is founded on the person of Peter, as on a Rock:

Saint Cyril of Alexandria: “He [Jesus] suffers him no longer to be called Simon, exercising authority and rule over him already, as having become His own. But by a title suitable to the thing, he changed his name into Peter, from the word petra (rock); for on him He was afterwards to found His Church.”

Is Peter only the Rock, or each successor also?

Certainly, the teaching of the Church is clear that Peter is the Rock on which the Church is founded. But this choice of Christ was a response to Peter’s expression of faith, “You are the Christ, the Son of the living God”. And so the faith of Peter, according to Luke 22:32, is never failing, Peter is called “the pillar of faith”, and the faith of Peter is called “rock-like”, all according to Vatican I. So while the Church is not founded on the faith of Peter, but on the person of Peter, this choice to make Peter the Rock, due to his supernatural faith (granted by God’s grace), includes the guarantee of a rock-like faith for Peter and for each and every one of his valid successors.

But how can the Church, founded on Peter as on a Rock, withstand the gates of Hell after Peter dies and each successor takes his Chair? At the beginning of the Church, at the Church’s establishment and the making of Her foundation, Peter is that foundational Rock. But also, he continues to be the Rock on which the Church is built; and so Peter as the Rock remains.

Vatican I: 2. For no one can be in doubt, indeed it was known in every age that the holy and most blessed Peter, prince and head of the Apostles, the pillar of faith and the foundation of the Catholic Church, received the keys of the kingdom from our Lord Jesus Christ, the Savior and Redeemer of the human race, and that to this day and forever he lives and presides and exercises judgment in his successors, the bishops of the Holy Roman See, which he founded and consecrated with his blood.”

“3. Therefore whoever succeeds to the Chair of Peter obtains by the institution of Christ himself, the primacy of Peter over the whole Church. So what the truth has ordained stands firm, and blessed Peter perseveres in the rock-like strength he was granted, and he does not abandon that governorship of the Church which he once received.

Peter presides over the Church through each of his successors, and so each successor is also that Rock.

Saint Jerome as quoted by Pope Benedict XVI: “This is what Jerome wrote: ‘I decided to consult the Chair of Peter, where that faith is found exalted by the lips of an Apostle; I now come to ask for nourishment for my soul there, where once I received the garment of Christ. I follow no leader save Christ, so I enter into communion with your beatitude, that is, with the Chair of Peter, for this I know is the rock upon which the Church is built’ (cf. Le lettere I, 15, 1-2).”

Pope Saint Leo I: “The order of truth remains; blessed Peter, keeping the strength of the rock, does not abandon the helm of the Church. Whatever We do rightly is his work, whose power lives in his See…. In the person of My lowliness he is seen, he is honored, in whom remains the care of all pastors and of the sheep of their charge. His power does not fail, even in an unworthy heir.”

Congregation for the Doctrine of the Faith, Cardinal Levada: “The Holy Father, Pope Benedict XVI, in an Audience granted to the Prefect of the Congregation for the Doctrine of the Faith, Cardinal William Joseph Levada, on January 14, 2011, approved the decisions of the Ordinary Session of the Congregation, and ordered their implementation. This action by the Holy Father should be understood in virtue of the mandate given by the Lord to Simon Peter as the rock on which He founded his Church (cf. Luke 22:32): ‘I have prayed for you, Peter, that your faith may not fail; and when you have turned to me, you must strengthen the faith of your brothers and sisters.’ This Scripture passage has long been applied to the role of the Successors of Peter as Head of the Apostolic College of Bishops; it also applies to the role of the Pope as Chief Shepherd and Pastor of the Universal Church.”

Cardinal Ratzinger: “The Successor of Peter is the rock which guarantees a rigorous fidelity to the Word of God against arbitrariness and conformism: hence the martyrological nature of his primacy.”

John Paul II: “The assistance that Christ promised to Peter also accompanies his successors, who are entrusted with the same task for the Church: ‘I have prayed for you that your faith may not fail; and when you have turned again, strengthen your brethren’ (Lk 22:32). So Peter becomes the ‘rock’ on which Christ can build his Church in history, by a gift from on high: the gift of faith, solemnly confessed at Caesarea Philippi: ‘You are the Christ, the Son of the living God’ (Mt 16:16).[References here]

Despite the wording used by Jerome, it is not merely the office or chair of Peter that is the Rock, but Peter and each of his successors. But this does not remove Peter as the Rock, since Peter presides through each of his successors. However, it is certain from many teachings throughout the centuries that the Church is founded upon Peter and his successors as on a Rock, and not merely on Peter himself, to the exclusion of his successors. This teaching does not contradict Peter as the perpetual Rock on whom Christ founded the Church, since Peter forever “lives and presides and exercises judgment in his successors”.

Is Peter the Rock or Christ?

Peter is the visible head of the Church, and Christ the invisible eternal Head of the Church. But these two are one, so that the Church does not have two heads. This mystical unity between Christ and His Vicar is crucial to the understanding of the Roman Pontiff as the head of the Church, the body of Christ.

Pope Pius XII: “Christ and His Vicar constitute one only Head” of the one Church [Mystical Body of Christ 40]. Other sources (Unam Sanctam; Roman Catechism) say the same thing, with Pope Boniface in Unam Sanctam rejecting out right that the Church has two heads (“like a monster”). Peter (and each successor) is the visible head, and Christ the eternal (invisible, we say) Head, but their unity gives the Pope divine authority, despite being a fallen sinner with a limited earthly reign.

I would say something similar about the Rock on which the Church is founded, Peter (and each successor) is the visible Rock and Christ is the eternal invisible Rock. And so, just as the clearly taught mystical unity between Christ and His Vicar constitutes one only Head, not two, this same mystical unity constitutes one only Rock: Christ and the Roman Pontiff. As for Peter, “for ever he lives and presides and exercises judgment in his successors the bishops of the Holy Roman See, which he founded and consecrated with his blood” (Pastor Aeternus 2, 2), and so Peter never ceases to be the Rock, in the sense that he presides through his successors.

Now notice what Pope Leo XIII teaches in Satis Cognitum 12:

“And since all Christians must be closely united in the communion of one immutable faith, Christ the Lord, in virtue of His prayers, obtained for Peter that in the fulfilment of his office he should never fall away from the faith. “But I have asked for thee that thy faith fail not” (Luke xxii., 32), and He furthermore commanded him to impart light and strength to his brethren as often as the need should arise: “Confirm thy brethren” (Ibid.). He willed then that he whom He had designated as the foundation of the Church should be the defense of its faith. “Could not Christ who confided to him the Kingdom by His own authority have strengthened the faith of one whom He designated a rock to show the foundation of the Church?” (S. Ambrosius, De Fide, lib. iv., n. 56).

“For this reason Jesus Christ willed that Peter should participate in certain names, signs of great things which properly belong to Himself alone: in order that identity of titles should show identity of power. So He who is Himself “the chief corner-stone in whom all the building being framed together, groweth up in a holy temple in the Lord” (Eph. ii., 21), placed Peter as it were a stone to support the Church. “When he heard ‘thou art a rock,’ he was ennobled by the announcement. Although he is a rock, not as Christ is a rock, but as Peter is a rock. For Christ is by His very being an immovable rock; Peter only through this rock. Christ imparts His gifts, and is not exhausted…. He is a priest, and makes priests. He is a rock, and constitutes a rock” (Hom. de Poenitentia, n. 4 in Appendice opp. S. Basilii [attributed to St. Basil]).

Pope Leo XIII teaches that Christ is the Rock on which the Church is founded, just as Christ is also the Head of the Church. But Peter and his successors are each Rock and Head due to their mystical unity with Christ. Peter is Head and Rock only through Christ. Since the Church is the body of Christ, Peter alone cannot be its Head; Christ must be the Head of His own body. But Christ gifted the Church with a visible Head, united to himself as one Head, and the same for the foundational Rock of the Church. That Rock is Peter and his successors, not Peter alone historically, but Peter in his successors. But Peter can only be the foundational Rock of the Body of Christ through Christ, the Cornerstone of the Church. These are not two different roles, Cornerstone and Rock. Rather, Christ is the Rock or Cornerstone (literally in Hebrew “Head of the Corner”) and so is Peter, through his mystical unity with Christ.

Pope Pius XII, Mystical Body of Christ, 40: Since He was all wise He could not leave the body of the Church He had founded as a human society without a visible head. Nor against this may one argue that the primacy of jurisdiction established in the Church gives such a Mystical Body two heads. For Peter in view of his primacy is only Christ’s Vicar; so that there is only one chief Head of this Body, namely Christ, who never ceases Himself to guide the Church invisibly, though at the same time He rules it visibly, through him who is His representative on earth. After His glorious Ascension into Heaven this Church rested not on Him alone, but on Peter, too, its visible foundation stone. That Christ and His Vicar constitute one only Head is the solemn teaching of Our predecessor of immortal memory Boniface VIII in the Apostolic Letter Unam Sanctam; [61] and his successors have never ceased to repeat the same.

The Church rests on Christ, as Her Rock, and on Peter as “its visible foundation stone”.

[1 Corinthians 10]
{10:1} For I do not want you to be ignorant, brothers, that our fathers were all under the cloud, and they all went across the sea.
{10:2} And in Moses, they all were baptized, in the cloud and in the sea.
{10:3} And they all ate of the same spiritual food.
{10:4} And they all drank of the same spiritual drink. And so, they all were drinking of the spiritual rock seeking to obtain them; and that rock was Christ.

Christ as Rock is that Rock on which the Church is founded:

Pope Pius II, oration “Multa hic hodie,” 21 November 1459, Mantu, Italy:

“We read that Moses stood on a rock in order to contemplate God’s face. On this rock almighty God has built his Church.”

So we see that it is not contradictory to say that Christ is the Rock on which almighty God has built his Church, but also that Peter is the rock on which almighty God has built his Church. For just as Christ and His Vicar constitute one only Head, so also does Christ and His Vicar constitute one only Rock on which the Church is founded. Without Christ, Peter cannot be Rock or Head of the Church. And Christ is with Peter and his successors so much so that each Pope has a mystical unity with Christ, the eternal Head and eternal Rock of the Church.

Ronald L. Conte Jr.