St Maximus stands at the bridge of East and West and expressed one of the highest concepts of Petrine Primacy found in the Greek Fathers. He also predicted the entire Filioque controversy around two centuries before it happened and pointed out that due to the linguistic differences between Greek and Latin terms, that both East and West believe the same thing.

He wrote: "All the ends of the earth, and all who in any place really confess the Lord in the true faith, turn their eyes to the most holy Roman Church and to her confession and faith, as to a sun of eternal light. . . . For since the beginning, when the Word of God came down to us, being made man, all the Churches of the Christians have received one only firm basis and foundation, the great Church that is there (at Rome), against which, according to the Saviour's promise, the gates of hell shall never prevail, and which holds the keys of the true faith in him, which gives the true and only piety to those who come to her devoutly, which shuts the mouth of all heretics."

And he writes of Pyrrhus, the Monothelite Patriarch of Constantinople (638-655) : " If he wants to neither be considered, nor to really be a heretic, he need not try to please first this one and then that one--to do this would be superfluous and unreasonable, because just as all are scandalized at him because one is scandalized, so if he satisfies this one, without doubt all will be satisfied. So let him hasten above all to satisfy the Roman See. If he agrees with her, every one will in all places call him pious and orthodox. Indeed, he is talking in vain if he tries to persuade people like myself before he has satisfied and begged forgiveness of the most blessed Pope of the holy Church of the Romans, that is, of the Apostolic See, which in all things and through all things commands and has authority and power of binding and loosening over the holy Churches of God all over the world, given by the very Word of God made man, as well as by all holy synods according to the sacred Canons."

Epistola ad Petrum, quoted by Fortescue “Orthodox Eastern Church”