Jerry’s Question #2:

At the fourth session of the sixth Ecumenical Council of Constantinople[680-681], the letter of Pope St. Agatho[678-681] was read:

... [Peter] also received from the very Redeemer of all, the Church’s spiritual sheep...by whose protection, this apostolic Church of his has never turned aside to any part of error, whose authority, as that of the prince of all the apostles, the entire Catholic Church of Christ, and the ecumenical councils, ever faithfully embracing, followed in all things... [Mansi 11: 239-42]

The Council wrote to Pope Agatho:

To you, therefore, as bishop of the first see of the universal Church, we readily leave [the decision about] what is to be done, standing as you are upon the firm rock of faith, having read the letter of the true confession sent by Your Paternal Beatitude to the most pious emperor, which we recognize as having been divinely written by the supreme summit of the apostles, through which we have driven off the newly arisen heretical sect of manifold error... [Mansi 11: 684]

According to St. Agatho the entire Catholic Church and the Ecumenical Councils followed "... this apostolic Church of his [that is Peter]." Further the other Patriarchates had fallen into heresy. Do you agree that the words "... this apostolic Church of his [that is Peter]," refer to the Roman Church?