Mark of Ephesus actually wasn’t far off. It has been demonstrated historically that a vast number of the most important manuscripts presented at Florence were highly corrupted. This revelation and vindication of many Orthodox complaints at the time, of course, does not fully resolve the Filioque debate. For the source, see: Siecienski, A. Edward. The Filioque: History of a Doctrinal Debate. New York: Oxford University Press, 2010.
The first florilegium composed in favor of the Filioque clause by Theodulf of Orleans in the late eighth or early ninth century contained excerpts thought to be by Athanasius. Now we know that is was not he who wrote it, so it is now understood to be pseudo-Athanasius.
No ways. Mark of Ephesus was way off and ambitious. He held a ridiculous theory that all the writings of the Latin saints brought forward at Florence , that is near the entire corpus of Latin saints, were forged because he could not explain how such saints could teach the filioque. The Latins proved in great lengths the teaching in their fathers .
If this revelation were true, articles upon articles, journals and encyclopedias as well as the internet and books would be filled with this information. Yet the opposite situation is reality. Academia does not recognize this “discovery” as worth merit evidently.
Yes there were a few forged texts especially amongst the Greek texts presented at Florence but that was proved to be the case for both sides (Greeks and Latins). The amount of forged texts at Florence amounted to nothing near a majority nor even a significant minority of the texts presented at the council.
In fact Bassarion, bishop of Nicaea and who left the council a roman cardinal, had this to say on the deliberations at the council concerning the filioque :
"They brought forward passages not only of the western teachers but quite as many of the eastern… to which we had no reply whatsoever to make that they were corrupt and corrupted by the Latins. They brought forward our own Epiphanius as in many places clearly declaring that the Spirit is from the Father and the Son: corrupt we said they were. They read the text mentioned earlier in Basil’s work against Eunomius: in our judgment it was interpolated. They adduced the words of the Saints of the West: the whole of our answer was ‘corrupt’ and nothing more.
We consider and consult among ourselves for several days as to what answer we shall make, but find no other defence at all but that…'
We had no books that would prove the Latin texts to be corrupt, no Saints who spoke differently from those put forward.
found ourselves deprived of a just case in every direction. So we kept silent ’ (.G. 161, 358CD)."
George Scholarius, however, though he was by no means unacquainted with the philosophy of the Latin Church, had not, as far as is known, been assailed by any previous doubts about the orthodoxy of his own Church. However, he shared Bessarion’s views as to the solidity of the Latin presentation of their doctrine :
"But you all see that the Latins have contended brilliantly for their faith so that no one with a sense of justice has any reason to reproach them… They brought forward from the common Fathers of the Church the six most renowned in dignity, wisdom and the struggles for the faith (I pass over the others) as witnesses of their doctrine, each of whom must be judged the equal of all the men in the world, and those not just incidentally and casually but as if they were for us judges of the present dispute.
They argued so precisely and clearly, expressing the question in exact words and as befits teachers, appending also the reasons and the texts of Holy Scripture from which they had drawn that doctrine as an inevitable conclusion, just as they culled others from other texts… . . Besides, they put forward others from the common Fathers, those of the East I mean, adorned with an equal wisdom and honor, who also said just the same as those others, though not so plainly, if their words are examined in a spirit of truth and wisdom, and they offered in proof of their doctrine no merely specious reasoning, no coercion, but everything straightforwardly and as flowing from the divine Scriptures and the Fathers. On our part nothing was said to them to which they did not manifestly reply with wisdom, magnanimity and truth, and we have no Saint at all who clearly contradicts them.
If indeed there were such, he should in some fashion or manner be made to harmonize with the majority much more justly than that the multitude of the Teachers should be forced into his mould… Nor shall we say that the Doctors are mutually contradictory, for this is to introduce complete confusion and to deny the whole of the faith.** Who is so simple-minded as to believe that the Latins wish to destroy the faith and to adulterate the trinitarian theology of all the Doctors? Surely a man who affirms this deserves nothing but ridicule, for no accusation would be disproved by more numerous, more weighty and more truthful arguments than this one**.’ (Speech, ‘On the Need of Aiding Constantinople’, addressed to the Greeks by Scholarius in Florence, in Schol. I, pp. 297-8, 299)."
The last highlighted part is a shot at the theory of mark of Ephesus who held that the Latins corrupted all their texts.
This reeks of an arrogance which stems from your inability to admit error when you manifestly are and an inability to accept a different conclusion being reached on the same set of material. (Photius , Mark Eugenikos and their writings). Say what you want but as far as this sub-topic goes, I’m done.