On the Divine Institution of The Papacy

Although many admit that the aforesaid text of the Gospel pertains to Peter alone, nevertheless some affirm that the whole of what was promised to Peter was given by Christ, on other occasions, to the rest of the apostles; and they affirm this to be true by many arguments from Sacred Scripture.

First, Matt. XVIII, it is said to the apostles collectively: whatever you shall bind upon earth shall be bound also in heaven; and whatever you shall loose upon earth shall be loosed also in heaven. Where it appears that the power previously promised to Peter was extended to all.

Second, John XX, the keys promised to Peter are conferred upon the apostles collectively, by saying: Whose sins you shall forgive, they are forgiven them; and whose sins you shall retain, they are retained.

Third, John XX also, Christ says to the apostles collectively: As the Father has sent me, I also send you. And likewise in Mark, the last [chapter], and Matt., the last [chapter], He sent them all collectively to teach, to preach, and so forth.

Next, the same is shown from fact: for in Acts VIII, Peter is read to have been sent, together with John, into Samaria by the apostles who were at Jerusalem. And in Acts XV, in the synod concerning the observance of the legal [ordinances], with Peter present, James gave the sentence, when he said I judge that they are not to be disturbed, and so forth. In Gal. II also, Peter and James and John, who seemed to be pillars, gave the right hands of fellowship to Paul and Barnabas. From these deeds the equality of Peter and the other apostles is confirmed.

Finally, a thousand authorities of the saints are brought forward sounding forth the equality of Peter and the other apostles: such as that of Cyprian — found in XXIV, q. I, the chapter "The Lord speaks" — who says that He bestowed equal power on all the apostles: and that the rest of the apostles were indeed that which Peter was, endowed with an equal fellowship both of honor and of power. And that of Jerome, Against Jovinian, Book I, chapter XIV: But if you say, the Church is founded upon Peter, although in another place the same thing is done upon all the apostles; and all receive the keys of the kingdom of heaven, and the strength of the Church is established equally upon them. And whatever others are similar.

For the clarification of these matters, know that from the Gospel text two things are found promised singularly to Peter, to which Origen added a third. The first is: Upon this rock I will build my Church; for this we read to have been promised to Peter alone. The second is: To you I will give the keys of the kingdom of heaven; which is found promised to no other. The third, noted by Origen, is that it is said to Peter: Whatever you shall bind upon earth shall be bound also in the heavens, in the plural number; and likewise whatever you shall loose upon earth shall be loosed also in the heavens; but to the apostles collectively it is said that they shall be bound or loosed in heaven, in the singular number. And he adds the reason: because they are not of as great perfection as Peter.

Among the four promises, therefore, made to Peter, the difference of the first from the others is clear: for it is agreed that one thing is signified by being about to be the foundation of the Church (which He explains, upon this rock I will build my Church) and another by being about to have the keys, and to loose and to bind. But the difference between the second (that is, between the keys of the kingdom of heaven) and the third and fourth, that is, to bind and to loose, is not everywhere evident: for according to the surface of the letter it appears that by the keys is [signified] the power, and by binding and loosing are set forth the acts of the power, so that the efficacy of the keys might be declared — namely, in what manner they attain to the kingdom of the heavens: for efficacy of this kind is manifested by saying whatever you shall loose upon earth shall be loosed also in the heavens; and because He had put beforehand the kingdom of the heavens in the plural, therefore He said in the plural in the heavens. And according to this sense the promise of the keys differs from the promise of loosing and binding, as the promise of the power [differs] from the promise explanatory of the acts of that [power].

But these things, though true, do not contain the whole meaning of the Gospel. That you may understand this more fully, know that acts of the keys are found to be of a twofold kind: for some are acts adequate to the keys themselves, but some are lesser than they. The former are, as it were, total acts; the latter, partial acts. Now the acts adequate to the keys are to open and to close; but the partial ones are to bind and to loose. I explain each. That to open and to close are the acts adequating the keys, both the words sound forth and the office of the keys most clearly testifies: for keys are only for opening and closing. Nor are there lacking testimonies of the Scriptures, both from the Old and from the New Testament: for in Isa. XXII, when it had been said and I will give the key of the house of David, there is subjoined and he shall open and he shall close; and likewise in Rev. III the same is repeated. But that to loose and to bind are acts of the keys, all the doctors testify. And that they are partial acts and not adequate to the keys, is clear from this: that to loose and to bind stand to opening and closing as parts to the whole; for everyone who looses someone opens the kingdom of heaven to him, but not everyone who opens the kingdom of heaven to someone looses him; and likewise everyone who binds closes, but not everyone who closes binds.

And lest we wander longer through many things, but that the solid reasoning together with the truth may be evident: to loose and to bind are judicial acts, whether in the sacrament of penance or in the ecclesiastical court; to open and to close are higher acts, comprehending under themselves both judicial acts and non-judicial acts; for by both the kingdom of heaven is closed and opened. And indeed that many close the kingdom of the heavens to others without a judicial bond, the Lord testifies, Luke XI, saying: Woe to you, lawyers, who have taken away the key of knowledge; you yourselves have not entered, and those who were entering you have hindered. But that they open the kingdom of heaven without an act of judgment, experience, the mistress of things, shows: while by the pastor's providence, governance, ordering, teaching, dispensation, commutation, and so forth, the kingdom of heaven is continually opened to the Church. The promise of the keys, therefore (to you I will give the keys of the kingdom of heaven), differs from the two remaining ones subjoined (and whatever you shall bind and whatever you shall loose) according to the thing promised: not only as power from acts, but as power from inadequate acts, that is, lesser and partial ones; so that when the keys were promised to Peter, the power of opening and closing the kingdom of heaven was promised; but when there was promised to the same one and whatever you shall bind and whatever you shall loose, the efficacy of the keys was set forth in the lesser acts: that we might perceive that, if the efficacy of the partial acts is so great, much more will the efficacy of the adequate acts attain to the heavens. Wherefore, in promising the keys, the whole is promised; but in promising the acts of loosing and binding, the whole is not promised, but partial acts are promised. And therefore, from the fact that the keys of the kingdom of heaven were promised to Peter alone, it must be admitted that to Peter alone was promised the power of opening and closing the kingdom of heaven: not that he alone can open and close the kingdom of the heavens (for, as has been said, whoever looses anyone opens the kingdom of heaven to him), but because he alone can [do] whatever pertains to opening and closing the kingdom of heaven — not for these or those, but for the Church built upon him by Christ. That this sense and this difference are verified according to the letter is declared from three things beyond the aforesaid. First, from the copulative conjunction always interposed in the Gospel text: for He says you are Peter, and upon this rock, and to you I will give the keys, and whatever you shall bind and whatever you shall loose; for the copulative conjunction intimates the diversity of the things promised. Second, because the Lord did not say and to whomever you shall open and to whomever you shall close, but He said whatever you shall loose and whatever you shall bind. For if He had wished to expound the keys, they would doubtless have had to be expounded by the adequate acts (which are to open and to close); but where He descended to binding and loosing, He made manifest that He was not expounding the keys, but passing to the lesser acts of the keys. Third, from the fact that He never promised or gave to the apostles the keys of the kingdom of heaven, or their adequate acts, namely to open and to close the kingdom of heaven; but He is read to have spoken with the apostles of the partial acts of the keys: both by saying whatever you shall bind upon earth, and so forth, and by saying whose sins you shall forgive, and so forth.

Instance. And if it be objected that not even to Peter did the Lord give or promise the acts adequate to the keys — because He indeed promised him the keys, but never promised that he would open and close: Far be it from the divine wisdom that it should have wrapped in silence the acts adequate to the keys; for when He explained of what the keys were, namely for opening and closing, He doubtless set forth the acts adequate to the keys, which are to open and to close. Now it is agreed that He added "of the kingdom of heaven" for this reason: that it might be expounded that the keys are of the kingdom of heaven, namely for opening and closing. By the very fact, therefore, that He promised to Peter alone the keys of the kingdom of heaven, He promised to Peter alone the adequate acts of the keys — or, what is the same, the keys according to the acts adequate to the keys; and after this promise He descended to the judicial acts, and whatever you shall bind and whatever you shall loose, as has been said.

From the Gospel text, therefore, two promises evidently remain [made] to Peter alone: that is, that he would be the foundation of the Church (upon this rock I will build my Church), and that the keys of the kingdom of heaven would be given to him: and to you I will give the keys of the kingdom of heaven.

Objection against the first promise. Nor are these things without objections. For against the first promise it is objected that either Christ alone is the foundation of the Church (according to that saying, 1 Cor. III, no one can lay another foundation besides that which has been laid, which is Christ Jesus), or, if a manifold foundation is admitted, Peter is not the sole foundation of the Church, but the other apostles also: according to that saying, Eph. II, built up upon the foundation of the apostles; and Rev. XXI, the wall of the city having twelve foundations, and in them the twelve names of the twelve apostles.

First objection. But against the second [promise] it is objected, first. If by the promise of the keys the whole power is promised, why, after the whole, are the parts promised? whatever you shall bind and whatever you shall loose; for these would have been promised in the whole.

Second. Secondly. If to loose and to bind are partial acts of the keys, why do the theologians, in distinctions XVIII and XIX of the fourth [book] of the Sentences, in treating of the keys, define them by the judicial acts which are to bind and to loose? For a definition ought to be given by the proper and adequate acts.

Third. Thirdly. Why do they affirm that the apostolic keys are given in the ordination of priests, if they confer on them only the lesser acts of the keys?

Fourth. Fourthly. Why do they call the keys the keys of the Church, and not the keys of Peter, if they were first given to Peter alone?

To the objections against the first promise. It is not, however, difficult to satisfy these. And to the objections against the first promise made to Peter, that he would be the foundation of the Church, it is answered: that to be the foundation of the Church simply, that is totally, is proper to Christ; but to be the foundation of the Church according to some time or according to some particular respect, has been communicated to others. And to the saints indeed, to whom the doctrine of the faith was revealed for the Church, it has been communicated to be a foundation under the respects of apostles and prophets; but to Peter, beyond the aforesaid respect, it was promised that he would be the foundation according to the respect of pastor of the whole Church of Christ — according to which respect it does not belong to the other apostles to be the foundation. And therefore "foundation" is said diversely in this threefold manner: for of Christ it is said with the exclusion of others (no one can lay another foundation, and so forth); but of the apostles and prophets it is said with the addition of the total foundation, that is, of Christ: since in Eph. II there is joined, with Christ Jesus himself as the highest cornerstone (where Augustine says: Lest the apostles or prophets, upon whom the city is founded, should hold themselves in themselves, upon Christ the whole leans, as upon the first foundation: which foundation is at the top, not at the bottom, as in a bodily building.) And in Rev. XXI there is subjoined, and of the Lamb, that is, of Christ. But concerning Peter, Christ himself adds, I will build my Church: so that it may be shown that the building of the Church depends principally upon Christ.

To the first [objection] against the second promise. But to the questions concerning the promised keys, it is said in answer that, after the whole was promised by the keys, the parts too were promised by whatever you shall bind and whatever you shall loose, for this reason: that the diversity of the things promised might in a second way be shown. (For if all things had been comprehended under a single promise without the copulative conjunctions, or if the keys alone had been promised, you would have thought the keys adequated and exhausted by these two, whatever you shall bind and whatever you shall loose. But now, because the diversity of the things promised has been shown so openly, by expressing each with copulative conjunctions, we clearly understand that not the whole which was promised to Peter is promised or conferred upon any other by the fact that there is promised or given whatever you shall bind and whatever you shall loose, and so forth; but that by this there is promised or given only that which was promised in the third and fourth place to Peter also.) And thence you would see that the first promises remain with Peter alone.

To the second. But to the second question it is answered that the keys were defined by the theologians through the acts of judgment because they were treating of the keys of order: as is clear in the text of the Master of the Sentences, both at the beginning of distinction XVIII (where Ambrose is brought forward saying: for this right is permitted to priests alone) and at the beginning of distinction XIX, where it is said these keys are given through the ministry of the bishop in the promotion to the priesthood: for when one receives the priestly order, he at the same time also receives these keys.

To the third. And by this the third question is resolved.

To the fourth. But to the fourth, which is not about the thing but about the name, and is therefore in a manner extraneous, it is answered that the keys are called both the Church's and Peter's: for Peter alone is called the key-bearer of the kingdom of heaven. And they are Peter's indeed as of the head who uses them, and as of him through whom they are derived to the Church; but they are the Church's both as its end (because it is for the sake of the Church that Peter has the keys) and as of her who uses them in her bishops and priests: yet in such wise that according to their totality the Church uses them in her head, but according to the partial uses she uses them in the bishops and other ministers. The solid opinion stated, therefore, remains.

To the first principal argument. But to the first of the arguments brought forward at the beginning: it is said that the Lord, by those words whatever you shall bind upon earth, and so forth, did not adequate the four promises made to Peter, but only the last two: as the letter itself testifies. And therefore the Lord did not say I will give to you, or to the Church, the keys of the kingdom of heaven, although He had said to Peter in the presence of the same, to you I will give the keys of the kingdom of heaven. Whence from this very fact, that to the other apostles the Lord said whatever you shall bind, and so forth, no mention being made of the keys, it is manifestly held that He did not repeat in the power of the others the whole that He had promised to Peter — as one about to commit the whole to Peter, but the parts to the others.

To the second. But to the second it is said that after the resurrection, by saying whose sins you shall forgive, and so forth, the keys were indeed given to the apostles, but not in their totality: since only the keys of order were given, as the doctors commonly and rightly say. Whence, according to the letter, when it is said whose sins you shall forgive, an ecclesiastical judge is constituted in the sacrament of penance, as far as concerns the part of order; but when in Matt. XVIII it was said to the same, whatever you shall bind upon earth, the discourse was of ecclesiastical judgment in the judicial court. Whence it is also commonly and rightly said that then the discourse was of the acts of the keys of jurisdiction, but afterwards of the acts of the keys of order. And since (as has been declared) neither judgment, even taken together, adequates the keys promised to Peter — but to loose and to bind in either court are partial acts of the keys promised to Peter — therefore by both powers together the power promised to Peter is not adequated. Whence those who devote themselves to disputations should beware of the sophists who object that the keys of order and the keys of jurisdiction adequate the keys of the Church. Poison lies hidden here: since, properly and formally speaking, the keys promised to Peter are higher both than the keys of order and than the keys of jurisdiction; and therefore the Lord expounded them not through the acts of order or of jurisdiction, but through the kingdom of heaven, doubtless to be opened or closed. So that, looking more keenly (as has been said) at the Lord's words to you I will give the keys of the kingdom of heaven: by that particle of the kingdom of heaven He expounded the keys through the adequate act, namely to open or to close; for the kingdom of heaven, to be opened or closed, carries with itself the act of opening or closing: and it is agreed that to open and to close the kingdom of heaven are acts far higher than all judicial acts, both of the keys of jurisdiction and of the keys of order.

Finally, to those who importunately insist that new keys are now being brought into the Church — for hitherto none have been heard of except the keys of order and the keys of jurisdiction; whence now a third [set of] keys in the Church of Christ? — I answer that I have not invented or fabricated new keys either in fact or in name; but if it is permitted to weigh these things in an even balance with the objections, the objectors will find that they argue against themselves: for neither the keys of order nor the keys of jurisdiction did Sacred Scripture hand down — but the doctors explained them; whereas the keys of the kingdom of heaven Christ the Lord consecrated with his own mouth. I speak of the keys of the kingdom of heaven; I do not introduce novelties: from the very words of the Lord, according to the literal sense more keenly understood, I make manifest what I say. But those who argue ought to consider more subtly the meaning of the doctors: and even from this very fact, that the doctors distinguish the keys of the kingdom of heaven into the keys of order and the keys of jurisdiction, [they ought] to understand that the keys of the kingdom of heaven are higher than both, and that both signify parts of the keys of the kingdom of heaven; and through this, that the keys of the kingdom of heaven signify a whole greater and higher than its parts when they are said simply and absolutely, as they were promised to Peter; but when they are applied to the parts, they signify both the keys of order and the keys of jurisdiction: for both are called keys of the kingdom of heaven. Whence it will be the office of the acute reader to discern when the doctors speak of the keys of the kingdom of heaven absolutely, and when of the keys of the kingdom of heaven as applied to order or jurisdiction.

To the third it is said: that the very words of the Lord testify that the discourse is of the authority of the apostolate when it is said, as the Father has sent me, I also send you: for to send and to be sent pertains to the apostolate, according to that saying, John XIII, the servant is not greater than his lord, nor is the apostle greater than he who sent him; and therefore from this nothing is had but a parity of the apostolate. And likewise through the other texts by which they were sent equally to teach and to preach, and so forth, nothing is had but a parity as to commissions of this kind: but to Peter, above all these, it was promised both that he would be the foundation of the Church, and that the keys of the kingdom of heaven would be given to him.

To the [argument from] authority. But to those things which are adduced from the deeds of the apostles, satisfaction is most easily made. For the theologians teach concordantly, in the first [book] of the Sentences, that the one sent need not be lesser than the one sending, nor even be from him: for the Son was sent by the Holy Spirit, than whom He is not lesser, and from whom He is not.

According to the letter, however, it is said that Peter was of such great humility that among the apostles he bore himself as one of them, and did not wish to use the power which he had; and therefore, as one of the apostles, he was sent by the same, together with John. And this humility of Peter is manifestly clear in Acts XI, when the other faithful of the circumcision disputed against him: which Gregory also noted (and it is found in II, q. VII, the chapter "Peter"), saying: Peter had received the power of the kingdom; and yet the same first of the apostles, to the complaint made against him by the faithful as to why he had entered in to the Gentiles, answered not from the power of his office, by which he could have said that the sheep should not accuse or rebuke their shepherd, but from the authority of the divine virtue by which the Gentiles had received the Holy Spirit.

And by these things it could likewise be said that, in the synod concerning the observance of the legal [ordinances], Peter comported himself as one apostle. Nevertheless, if the matter done is rightly noted, neither was Peter consulted, nor the apostles alone, but the apostles and the presbyters at Jerusalem; and therefore the conclusion was made neither by Peter nor by James, but by the apostles and the elders with the whole Church — though they wrote in the name of the apostles and the elders. Whence it is false that James pronounced the sentence: since the sentence is the conclusion, which is agreed to have been made by all; but when James said I judge, it is just as if he had said "this is my judgment." Whence James is introduced not as judging, but as answering: for thus we read, And after they had been silent, James answered. Nay rather, Peter seems to have borne the person of the pastor at the beginning: since he, rising up first and alleging the divine grace, rebuked those who were calling into doubt the freedom from the legal [ordinances]. For we read thus: And when there was a questioning, Peter, rising up, said, and so forth. Where Peter's authority is shown.

As for the fact that Peter, finally, gave the right hands of fellowship together with the others: he did this which the Supreme Pontiff does daily, holding all the bishops not only as associates but as brothers.

To the authorities, finally, of the holy doctors sounding forth the equality of Peter and the other apostles: it is said that they are verified concerning their parity according to the apostolate; for all were equal in apostolic authority.

Instance. And if it be objected that under the apostolic power could be comprehended all that Peter could [do]: a satisfactory response is at hand, that, granted that a comprehension of this kind were true, yet from it there would not follow an equality with Peter in every way: for their powers would be equal as to the things which they could do, but they would not be equal extensively, nor as to the manner. For the apostles received power from Christ as apostles, that is, as legates; but to Peter, above the apostolate, there was promised (as will be manifested below) power as to the ordinary pastor of the Church. And hence appears both the higher degree and the unity of Peter's power, and its greater extension, since it extended even to the apostles themselves, inasmuch as they were Christ's sheep.

Nor should you make little of the difference in respect of the manner of having: for there is danger of a great fall if they are confused. For it is one thing to have the keys as apostles, and another to have the keys as the head and pastor even of the apostles themselves: the former does not derogate from Peter's singular excellence, but the latter sets Peter himself above all, and places him over all the apostles and over the whole Church. To the difference of these manners it pertains that the Lord promises the keys to Peter alone, but to the others He does not give the keys, but delegates or bestows those things which are of the keys: whether in Matt. XVIII, or John XX, or Matt. and Mark, the last [chapter], or Luke XXII, I dispose to you a kingdom, as my Father has disposed to me. And that the authorities brought forward at the first may be made manifest: it is clear that Cyprian confesses the apostles to be equal in such a way that nevertheless he says the Church is built upon the one Peter (from the words of the Lord, upon this rock), and says that the Lord by his own authority disposed that ecclesiastical unity should have its origin from the one Peter. Jerome too, leaving the words of Christ in Matthew, you are Peter, and so forth, to Peter alone, transfers himself to another passage where similar things are narrated as given to the apostles, enumerating three things. First, that the Church is founded upon all the apostles: for that this is done was promulgated in Eph. II, built up upon the foundation of the apostles. The second, namely that all the apostles receive the keys of the kingdom of heaven, is had in Matt. XVIII, whatever you shall bind, and John XX, whose sins you shall forgive. And the third, that the strength of the Church is established equally upon them, is taken from the texts related, namely Matt. and Mark, the last [chapter], and Luke XXII, and John XX, or even from other similar texts; whence it is clear from what has already been said that the equality of the apostles, inasmuch as they are apostles — both in founding the Church, and in the keys of jurisdiction and of order, and in the strength of doctrine, of miracles, and of life, which establish the strength of the Church (which Jerome affirms) — in no way hinders Peter's singular authority, by which he alone is set over the whole Church. Whence Jerome also there immediately subjoins: nevertheless for this reason one among the twelve is chosen, that, a head being constituted, the occasion of schism might be removed. Where you manifestly see that he called the apostles equal, equal in respect of the apostolate, in such a way that nevertheless Peter, chosen and constituted by Christ, is the head of all: for this indeed is what we maintain. This pertains to the difference of the manner of having: since hence you have that all had these things as apostles, but beyond this manner Peter had them singularly as the head of all. And from these two authorities, thus explained, we think it easy that the rest are to be rightly interpreted according to the sense of the aforesaid.

And that this is the true sense of the doctrine of the saints is manifested in three ways. First, from the fact that they call the apostles equal, not only in power but in honor: which, unless it be referred to the apostolate, is agreed to be false, since Peter manifestly had the primacy of honor according to all. Second, from the Gospel texts which the saints bring forward to prove an equality of this kind: for they bring forward those which we have now discussed, from which it is agreed that no more is had than an equality according to the apostolate. Third, from the reasoning which they use: namely because Peter, in the person of the Church, alone received the keys, and so forth, that the unity of the Church might thereby be proved.

Here, on account of the schismatics, stay your foot: and know that the unity of the Church commended by the unity of Peter can be understood in two ways. First, so that there is signified the unity of the Church in Christ, the one head, and in the unity of the articles of faith, of the sacraments of the Church, and of hope and charity. Second, so that there is signified the unity of the Church simply and absolutely united in the one head, in Christ's vicar on earth, namely Peter. The schismatics choose the first sense from the true and holy doctrine of the saints, which often explains the unity of the Church through those things which are enumerated in the first sense: truly indeed, but not totally, unless under the unity of the head, namely of Christ, Christ himself be understood in himself and in his vicar on earth — Christ himself as the head, but Peter as the vice-head. And this is therefore sometimes left unsaid: because, the head being accepted, it is customary to understand that he himself is accepted, in himself and in his vicar while he is absent.

But the second sense (in which the first is included, with the unity of the head on earth adjoined) is common to all Catholics; and it is proved in four ways. First: because, for designating the unity of the Church in its heavenly head, Jesus Christ, the unity of Peter is not fitting; but the unity of Christ himself both sufficed and most becomingly fitted: which the Lord here did not pass over in silence, but expressed, saying I say to you, and again I will build my Church, and again I will give the keys. But, the divine wisdom (which is Christ) disposing all things sweetly, it has no difficulty that the unity of the Church should most fittingly be signified, through the unity of Peter, in an earthly head in place of Christ.

Second, from the fact that the trust of history would be endangered: for Peter would be, as it were, similar in these things to the little child whom, in Matt. XXIV, the Lord, calling to himself, set in the midst of the disciples, saying, unless you be converted and become as a little child, and so forth. For just as that little child was taken up as an example or likeness of humility, so Peter would have been named as an example or likeness of unity; and through this, just as for the trust of history it is of no care who that little child was, so it would be of no or little care to the Church whether it was Simon Peter to whom it was said, to you I will give the keys of the kingdom of heaven, and so forth — which, however, offends the ears of all the doctors and of the whole Church. The sense of the saints, therefore, is: that according to the trust of history the matter was so done that the keys were promised to the one Simon Peter, so that the thing might signify the thing — so that the one Peter, being about to receive the keys first, might signify the unity of the Church.

Third, from the fact that it is necessary to save not only the signification but also the derivation: that is, not only that the unity of the Church be signified through the unity of Peter, but also that the unity of the Church should proceed from the unity of Peter, as Cyprian says in the authority brought forward. The Lord speaks to Peter, I say to you that you are Peter, and upon this rock I will build my Church: upon one He builds the Church. And although He bestows equal power on all the apostles after his resurrection, saying as the Father has sent me, I also send you; receive the Holy Spirit: nevertheless, that He might manifest the unity, He by his own authority disposed the origin of that same unity to begin from one. Where you manifestly see, from this that the Lord by his own authority disposed the origin of ecclesiastical unity to begin from one, that not only the signification of unity from one, but the derivation of unity from one, is asserted. For for signifying there was no need of authority; but for this, that the unity of the Church should have its beginning from the one Peter, there was need of the authority of Christ: for He could, if He had willed, have instituted the unity of the Church to proceed from the multitude of the apostles.

Fourth, because the unity of the Catholic Church is opposed not only to heresy, but to schism. But if the unity of the Church were regarded only in respect of the unity of the heavenly head, and of his sacraments and of the thing hoped for, believed, and loved, the unity of the Church would not be opposed to schism: for with a unity of this kind schism can stand, as is clear from the fact that those are held to be schismatics who are separated from the unity of the apostolic see. From this, therefore, that the unity of the Church is signified through the one Peter, it is not excluded — nay rather, from the manner in which it is signified through Peter, it is included — that the one Peter received the keys, so that he might not only signify the unity of the Church, but also begin and preserve it. And if this — namely, the unity of the Church receiving the keys — be looked at more keenly: both more truly and more perfectly is it done and signified by the keys being received in her one head, Peter, than if the Church were to receive them not in Peter but absolutely: since the unity of the head, receiving the keys, not only signifies the unity of the Church but also constructs it, as it also preserves it — all of which the Church would lack if one head had not been provided for her by Christ the Lord. And from this you have whence you may rightly understand the innumerable authorities of the saints.