I've dealt elsewhere with the famous "universal bishop" pseudo-dispute involving Gregory the Great. Catholic apologist Phil Porvaznik has treated it in some considerable depth. Protestant historian Philip Schaff (though somewhat perplexed) makes short work of this "universal bishop" argument, which purports to prove something against the historic papacy:
On the other hand, it cannot be denied that Gregory, while he protested in the strongest terms against the assumption by the Eastern patriarchs of the antichristian and blasphemous title of universal bishop, claimed and exercised, as far as he had the opportunity and power, the authority and oversight over the whole church of Christ, even in the East. “With respect to the church of Constantinople,” he asks in one of his letters, “who doubts that it is subject to the apostolic see?” And in another letter: “I know not what bishop is not subject to it, if fault is found in him.” “To all who know the Gospels,” he writes to emperor Maurice, “it is plain that to Peter, as the prince of all the apostles, was committed by our Lord the care of the whole church (totius ecclesiae cura) ....See also the General Audience (4 June 2008) of Pope Benedict XVI, on Pope St. Gregory the Great, another essay by Fr. Edward Hawarden, and the papal encyclical Iucunda Sane / On Pope Gregory the Great, by Pope St. Pius X (12 March 1904).
We have no right to impeach Gregory’s sincerity. But he was clearly inconsistent in disclaiming the name, and yet claiming the thing itself. The real objection is to the pretension of a universal episcopate, not to the title. If we concede the former, the latter is perfectly legitimate. And such universal power had already been claimed by Roman pontiffs before Gregory, such as Leo I., Felix, Gelasius, Hormisdas, in language and acts more haughty and self-sufficient than his.
(History of the Christian Church, Volume IV: Mediaeval Christianity. A.D. 590-1073, § 51. Gregory and the Universal Episcopate)
As with Pope St. Leo the Great, Pope St. Gregory the Great leaves little doubt as to his overall view of the sublime power and authority of the papacy:
Who could be ignorant of the fact that the holy church is consolidated in the solidity of the prince of the Apostles, whose firmness of character extended to his name so that he should be called Peter after the 'rock', when the voice of the Truth says, 'I will give to thee the keys of the kingdom of heaven'. To him again is said "When after a little while thou hast come back to me, it is for thee to be the support of thy brethren.An article in This Rock (December 1992) provides many examples of Gregory's papal power:
(Epistle 40; in Michael Winter, St. Peter and the Popes, Baltimore: Helicon, 1960, 66)
Inasmuch as it is manifest that the Apostolic See, is, by the ordering of God, set over all Churches, there is, among our manifold cares, especial demand for our attention . . .
(Letter to Subdeacon John; Register of the Epistles, Book III, Epistle 30; NPNF 2, Vol. XII)
To all who know the Gospel it is clear that by the words of our Lord the care of the whole Church was committed to Blessed Peter, the Prince of the Apostles . . . Behold, he received the keys of the kingdom of heaven, the power to bind and loose was given to him, and the care and principality of the entire church was committed to him . . .
(Epistles, 5, 37: To Emperor Maurice; NPNF 2, Vol. XII)
Yet I exhort thee that, as long as some time of life remains for thee, thy soul may not be found to be divided from the church of the same blessed Peter, to whom the keys of the heavenly kingdom were entrusted and the power of binding and loosing was granted, lest if his benefit be despised down here, he may close up the entrance to life up there.
(The Great Epistles, B IV, Ep. 41), in J. P. Migne, Patr. Lat., translated by John Collorafi)
Gregory to John, etc.
The care of our pastoral office warns us to appoint for bereaved churches bishops of their own, who may govern the Lord's flock with pastoral solicitude. Accordingly we have held it necessary to appoint you, John, bishop of the civitas Lissitana (Lissus, hodie, Alessio?), which has been captured by the enemy, to be cardinal in the Church of Squillacium, that you may carry on the cure of souls once undertaken by you, having regard to future retribution. And although, being driven from your own Church by the invading enemy, you must govern another Church which is now without a shepherd, yet it must be on condition that, in case of the former city being set free from the enemy, and under the protection of God restored to its former state, thou return to the Church in which you were first ordained. If, however, the aforesaid city continues to suffer under the calamity of captivity, you must remain in this Church wherein you are by us incardinated. Moreover, we enjoin you never to make unlawful ordinations, or allow any bigamist , or one who has taken a wife who was not a virgin, or one ignorant of letters, or one maimed in any part of his body, or a penitent, or one liable to any condition of service, to attain to sacred orders. And, should you find any of this kind, you must not dare to advance them. Africans generally, and unknown strangers, applying for ecclesiastical orders, on no account accept seeing that some Africans are Manichæans, and some have been rebaptized; while many strangers, though being in minor orders, are proved to have pretended to a higher dignity. We also admonish your Fraternity to watch wisely over the souls committed to you, and to be more intent on winning souls than on the profits of the present life. Be diligent in keeping and disposing of the goods of the Church, that the coming Judge, when He comes to judge, may approve you as having in all respects worthily executed the office of shepherd which you have taken upon you.
(Book II, Letter 37: To John, Bishop of Squillacium [Squillace, in Calabria]; NPNF 2, Vol. XII)
Now as to your declaring that you cannot possibly be ignorant of the degrees of ecclesiastical rank, I too fully know them with regard to you; and I am therefore much distressed that, if you knew the order of things, you have failed, to your greater blame, in knowing it with regard to me. For, after letters had been addressed to your Blessedness by my predecessor and myself in the cause of the archdeacon Honoratus, then, the sentence of both of us being set at nought, the said Honoratus was deprived of the rank belonging to him. Which thing if any one of the four patriarchs had done, such great contumacy could by no means have been allowed to pass without the most grievous offense. Nevertheless, now that your Fraternity has returned to your proper position, I do not bear in mind the wrong done either to myself or to my predecessor.
(Book II, Epistle 52, to Natalis, Bishop of Salona; a city located in what is now Croatia)
Gregory demonstrated this in his actions. He made it his business to approve candidates for the office of bishop. He rigorously examined men proposed for bishop and, rejecting some as unsuitable for the job, ordered that others be nominated instead (Epistles 1:55, 56; 7:38; 10:7). This is hardly behavior one would expect from a pope who renounced the idea of his having jurisdiction over other bishops.His Epistle 37 to Emperor Maurice, from Book V leaves no doubt whatever on the matter:
Like his predecessors and successors, Gregory promulgated numerous laws, binding on all other bishops, on issues such as clerical celibacy (1:42, 50; 4:5, 26, 34; 7:1; 9:110, 218; 10:19; 11:56), the deprivation of priests and bishops guilty of criminal offenses (1:18, 32; 3:49; 4:26; 5:5, 17, 18), and the proper disposition of church revenues (1:10, 64; 2:20-22; 3:22; 4:11).
To all who know the Gospel it is obvious that by the voice of the Lord the care of the entire church was committed to the holy apostle and prince of all the apostles, Peter . . . Behold, he received the keys of the kingdom of heaven, the power to bind and loose was given to him, and the care and principality of the entire church was committed to him . . . Am I defending my own cause in this matter? Am I vindicating some special injury of my own? Is it not rather the cause of Almighty God, the cause of the universal church? . . . And we certainly know that many priests of the church of Constantinople have fallen into the whirlpool of heresy and have become not only heretics but heresiarchs . . . Certainly, in honor of Peter, the prince of the apostles, 'the title 'universal'] was offered to the Roman pontiff by the venerable Council of Chalcedon.Other similar statements nail down the "papal case":
(from Monumenta Germaniae historica: Epistolae; Berlin: 1891 - , Vol. I, 321-322; cited in Jaroslav Pelikan, The Emergence of the Catholic Tradition (100-600), University of Chicago Press, 1971, 352)
. . . the prelates of this apostolic see, which by the providence of God I serve, had the honor offered to them of being called 'universal' by the venerable Council of Chalcedon."Sentiments like this from Gregory the Great led Jaroslav Pelikan (Lutheran at the time of writing and later Orthodox), in the same work, to declare:
(Book V, Epistle 44; from Monumenta Germaniae historica: Epistolae; Berlin: 1891 - , Vol. I, 341; cited in Pelikan, ibid., 354)
. . . who would doubt that it [the church of Constantinople] has been made subject to the apostolic see . . .
(Book IX, Epistle 26; from Monumenta Germaniae historica: Epistolae; Berlin: 1891 - , Vol. II, 60; cited in Pelikan, ibid., 354)
. . . without the authority and the cobsent of the apostolic see, none of the matters transacted [by a council] have any binding force.
(Book IX, Epistle 156; from Monumenta Germaniae historica: Epistolae; Berlin: 1891 - , Vol.II, 158; cited in Pelikan, ibid., 354)
Although earlier pontiffs, notably Leo I, had set forth much of the content of the doctrine of papal primacy and authority, , there is probably no exaggeration in the conventional view, which sees the teaching and practice of Gregory I as the significant turning point for the papacy, not only jurisdictionally but also theologically. In the course of exercising his office he established the doctrinal foundation for his administrative decisions, and in one of his letters [V, 37] he summarized the doctrine . . .Since the late Dr. Pelikan was not a Catholic, he cannot be accused of Catholic bias in concluding this.