Where did the papacy come from?

"I also tell you that you are Peter, and on this rock I will build my assembly, and the gates of Hades will not prevail against it. I will give to you the keys of the Kingdom of Heaven."

The translation quoted here footnotes both halves: Peter is petros, "the word for a specific rock or stone", and the rock is petra, "a rock mass or bedrock". The pun is in the Greek, which is why the sentence can be read in more than one way without anybody being dishonest.

The Catholic Encyclopedia answers that behind the Greek stands one Aramaic word, the Cephas of John’s Gospel, and that in the original the name and the rock are "one and the same".

A letter opens "The church of God which sojourns at Rome, to the church of God sojourning at Corinth" and proceeds to tell Corinth, at length, that the presbyters it has deposed could not justly be removed, and that the leaders of the revolt should submit: "you therefore, who laid the foundation of this sedition, submit yourselves to the presbyters, and receive correction so as to repent."

The letter names no author. Tradition calls it Clement’s. What is on the page is a church in one city instructing a church in another, with confidence, before the first century is out.

Irenaeus points to "the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul", and says "it is a matter of necessity that every Church should agree with this Church, on account of its preeminent authority".

Irenaeus wrote in Greek, but Against Heresies has come down entire only in a Latin version, the Greek surviving in fragments quoted by later writers, so the edition cited here prints the Latin beside the translation: potiorem principalitatem.

Even the verb is argued over. Convenire, rendered "agree with" here, has also been translated "resort to", which makes Rome a place the faithful gather rather than a standard they meet. That is the sort of detail that matters when a sentence is asked to carry this much.

Chalcedon’s twenty-eighth canon grants the see of Constantinople the same privileges as Rome, and states the principle it is working from: "the Fathers rightly granted privileges to the throne of old Rome, because it was the royal city."

It also ranks Constantinople next after Rome, so the council is reordering a hierarchy rather than levelling it.

That is a political account of Rome’s standing, adopted at an ecumenical council. The Roman legates were not in the room when it passed. They objected at the next session, said that what was done "during our absence" should be rescinded, and asked for their opposition to be entered in the minutes if it was not. Both the claim and the objection are in the acts.

The presiding officials ruled that "the whole synod has approved what we proposed". In May of the next year Pope Leo wrote to the empress Pulcheria that the bishops’ assent, being against the canons of Nicaea, "we do not recognize, and by the blessed Apostle Peter’s authority we absolutely dis-annul". Rome answered a political reason with Nicaea and with Peter.

The wordplay is real: Peter, and on this rock. Two churches that read it differently say so in their own documents. The Second Vatican Council reads the rock as Peter: "our Lord placed Simon alone as the rock and the bearer of the keys of the Church". The Lutheran confessions read it as what Peter said: the church is built "upon the ministry of the confession which Peter made, in which he proclaims that Jesus is the Christ, the Son of God."

Nothing in the sentence says the promise passes to anyone after Peter. The Second Vatican Council teaches that his office does: "the office granted individually to Peter, the first among the apostles, is permanent and is to be transmitted to his successors".

Irenaeus gives a succession list, Linus then Anacletus then Clement, written eighty years after the last of them. The letter to Corinth, from the period itself, is written in the name of a church rather than a man and refers to presbyters in the plural.

A second Roman text from the same milieu, the Shepherd of Hermas, which names Clement as the man who sends letters abroad, has its author told to read his book "in this city, along with the presbyters who preside over the Church". The presiding is plural there too.

Ignatius of Antioch, writing to Rome early in the second century, greets a church that "presides in the place of the region of the Romans" and tells it "I do not, as Peter and Paul, issue commandments unto you", but names no bishop there, though his letters to Ephesus, Magnesia and Tralles each name theirs.

Historians comparing the lists in the nineteenth century read this as a church led by presbyters, with a single bishop over the whole city emerging in the second century; Lipsius put the change around 140. That does not make the lists fabrications; it makes them later than what they describe. The Catholic Encyclopedia of 1911 took the other side, and called Peter’s own Roman bishopric "so well attested as to be historically certain".

A church that writes with authority to another church may be exercising a right or may be doing what the oldest and largest congregation in the capital would do anyway, and be listened to for the same reason.

The texts do not settle it, and their readers divide here. The Catholic Encyclopedia of 1911 sees in the letter a bishop of Rome "intervening in the affairs of another Church and claiming to settle the matter". The Moscow Patriarchate, in 2013, says Orthodox theologians have held that Rome’s primacy of honour is "instituted not by God but men". Philip Schaff, the church historian, saw in the same letter "the easy and as yet innocent beginning of the papacy".

Schaff called the chronology of its early bishops obscure and named the catalogues of popes as its principal sources. Those catalogues were made much later than the bishops they list, and the letter the church sent to Corinth is read for what it implies.

The question of who was in charge, in a modern sense, may not have had an answer at the time that anybody there would recognise.

The Second Vatican Council states it plainly: "in virtue of his office, that is as Vicar of Christ and pastor of the whole Church, the Roman Pontiff has full, supreme and universal power over the Church", and the college of bishops holds supreme power too, but only "together with its head the Roman Pontiff and never without this head".

The council presents this as instituted, not as grown: it proposes "all this teaching about the institution, the perpetuity, the meaning and reason for the sacred primacy of the Roman Pontiff" to be firmly believed. Whether the office grew, and if it did, whether into what it was given or into something else, is the disagreement in one sentence.

The Moscow Patriarchate sets out its account of the Orthodox position on the universal level: primacy there is "primacy in honour", fixed by the order of the diptychs, which belonged to the see of Rome through the first millennium, and the canons behind that order "do not vest the primus ... with any powers on the church-wide scale". Universal jurisdiction is the addition it does not accept.

Reformation confessions are blunter. Westminster: "There is no other head of the church but the Lord Jesus Christ. Nor can the pope of Rome, in any sense, be head thereof."

Rome and the Lutheran confessions both read Matthew 16 closely, and come out in different places. Neither is ignoring the text, which is worth knowing before anyone calls the other ignorant of it.