It is also shown that Peter is the Vicar of Christ and the Roman Pontiff is Peter’s successor enjoying the same power conferred on Peter by Christ. For the canon of the Council of Chalcedon says: “If any bishop is sentenced as guilty of infamy, he is free to appeal the sentence to the blessed bishop of old Rome, whom we have as Peter the rock of refuge, and to him alone, in the place of God, with unlimited power, is granted the authority to hear the appeal of a bishop accused of infamy in virtue of the keys given him by the Lord.” And further on: “And whatever has been decreed by him is to be held as from the vicar of the apostolic throne.”
Likewise, Cyril, the Patriarch of Jerusalem, says, speaking in the person of Christ: “You for a while, but I without end will be fully and perfectly in sacrament and authority with all those whom I shall put in your place, just as I am also with you.” And Cyril of Alexandria in his Thesaurus says that the Apostles “in the Gospels and Epistles have affirmed in all their teaching that Peter and his Church are in the place of the Lord, granting him participation in every chapter and assembly, in every election and proclamation of doctrine.” And further on: “To him, that is, to Peter, all by divine ordinancebow the head, and the rulers of the world obey him as the Lord Jesus himself.” And Chrysostom, speaking in the person of Christ, says: “Feed my sheep (John 21:17), that is, in my place be in charge of your brethren" (St. Thomas Aquinas, Against the Errors of the Greeks. Found in James Likoudis, Ending the Byzantine Greek Schism (New Rochelle: Catholics United for the Faith, 1992), pp. 182-184).
With the exception of the last reference to Chrysostom all of Thomas’ references cited to Cyril of Jerusalem, Cyril of Alexandria, Chrysostom and the Council of Chalcedon are forgeries. The remainder of Aquinas’ treatise in defense of the papacy is similar in nature. Edward Denny gives the following historical summary of these forgeries and their use by Thomas Aquinas
In the Pseudo-Isidorian Decretals alone 313 of the 324 claims attributed to your religion are false; lies...The question is, how many of these 313 lies does the modern Catholic church still teach as truth, even knowing they are lies???
Your underlying assumption, Iscool, is that all the Petrine theories referenced in the Pseudo-Isidore Decretals (PID), originated in the PID or gain their sole or principal support there. This is not the case.
Every time we in the FR Religion Forum have these discussions of Catholic doctrine, I urge both Catholics and non-Catholics to make reference to the Catechism of the Catholic Church. Rarely have I seen people do this, for reasons I cannot fathom. Anyhow, if you want an overview on the papacy, do try the Catechism, for instance here (Link) --- the footnotes will give you some primary sources to chew on. I assure you they do not rest --- not even a molecule's worth --- upon dodgy 9th century Frankish Dan-Ratherisms.
As to the (I believe it was sasportas') question about whether Pope Nicholas I lied about the forgeries having been in the papal archives for centuries, it looks like he himself was victim of his own archivist's misrepresentations. According to historian Warren Carroll, the PID were first brought to Rome by a Bishop Rothad, who had been deposed from his See of Soissons in Frankish territory by a good canonist, the Archbishop Hincmar of Reims; Rothad appealed his deposition to the Pope.
Rothad brought these documents with him to bolster his appeal (whether he knew they were forgeries or not, Carroll doesn't speculate, but they were apparently supplied to him via his Frankish allies); but Pope Nicholas' unscrupulous librarian, Anastasius (a former antipope) accepted them eagerly and uncritically, and represented them to Pope Nicholas as being of great antiquity.
According to Warren Carroll:
"They were used extensively in a letter to the West Frankish bishops (probably drafted by Anastasius) explaining and justifying Pope Nicholas' order of January 865 restoring Bishop Rothad to his see of Soissons. However, the main purpose of the 'false decretals' was not to strengthen Papal primacy, which was already well established, but to provide the appearance of more canonical safeguards for bishops. The 'false decretals' did not, therefore, play a major role in gaining public acceptance of Papal governance of the Church.
I'm not going to include Carroll's primary footnotes, many of which go back to Latin, French, and German sources (unfortunately, I don't read these languages) but his one English source is, voila, the Catholic Encyclopedia, which has already been referenced by both bkaycee and myself.
Another good source is the Wikipedia article on Pope Nicholas I, here (Link), which in turn references sources in German.
One enlightening detail from Wiki:
A question that is important in judging the integrity of this pope is whether he made use of the forged pseudo-Isidorian papal decretals. After exhaustive investigation, Schrörs has decided that the pope was neither acquainted with the pseudo-Isidorian collection in its entire extent, nor did he make use of its individual parts. He perhaps had a general knowledge of the false decretals, but did not base his view of the law upon them and owed his knowledge of them solely to documents that came to him from the Frankish Empire.Footnote: [Schrörs, "Papst Nikolaus I. und Pseudo-Isidor" in Historisches Jahrbuch, XXV (1904), 1 sqq.; Idem, "Die pseudoisidorische 'Exceptio spolii' bei Papst Nikolaus I" in Historisches Jahrbuch, XXVI (1905), 275 sqq.].
There, now we all know a whole lot more about Frankish forgeries of the 9th century Carolingian period.
I did, by the way, make the effort to digest a whole lot of material to write this in reasonably brief summary form.
Please spare me any more long cut-and-pastes. Please. I still have my dishes, my garden, and my yet-to-be-scrubbed bathroom awaiting me. I've just given you all I can constructively offer. Tolle, lege.