Would this be an accurate description of the misunderstanding at Chalcedonian between Rome and the Oriental Orthodox (i.e. Coptic, Syriac, etc)?

[Zekariya]

I pray for reunion.

Pope St Leo’s the tome is part of what divided the Catholic Church from the Oriental Churches. Different language and culture had a lot to do with this. Some of his tome can be viewed as supporting nestorianism.

“For each “form” does the acts which belong to it, in communion with the other; the Word, that is, performing what belongs to the Word, and the flesh carrying out what belongs to the flesh; the one of these shines out in miracles, the other succumbs to injuries. And as the Word does not withdraw from equality with the Father in glory, so the flesh does not abandon the nature of our kind.” - The Council of Chalcedon, The Tome of Pope St Leo of Rome

To paraphrase, “The Word preforms His duties and the flesh preforms its duties in communion with each other.” And then we see:

"[Christ said,] Behold my hands and my feet, that it is I myself; handle me and see, for a spirit hath not flesh and bones, as ye see me have:” that the properties of the Divine and the human nature might be acknowledged to remain in him without causing a division, and that we might in such sort know that the Word is not what the flesh is, as to confess that the one Son of God is both Word and flesh. - The Council of Chalcedon, The Tome of Pope St Leo of Rome

The Coptic Alexandrians would have probably been more comfortable with saying that there is one Son of God (the Word of God the Father) who is both God and Man. Pope St Cyril of Alexandria seems to contradict the Tome of Pope St Leo of Rome:

If anyone shall divide between two persons or subsistences those expressions which are contained in the Evangelical and Apostolical writings, or which have been said concerning Christ by the Saints, or by himself, and shall apply some to him as to a man separate from the Word of God, and shall apply others to the only Word of God the Father, on the ground that they are fit to be applied to God: let him be anathema. - Pope St Cyril of Alexandria, Twelve Anathemas, Anathema IV

Pope St Leo used “Son of God” to mean “Jesus” and “the Word” to mean “divinity” and “flesh” to mean “humanity”. Pope St Cyril of Alexandria used “the Word of God the Father” to mean “Jesus”. Therefore, when the Coptic Alexandrians hear that Pope St Leo has divided the Word from the flesh, it makes sense that they’d veiw him as a nestorian heretic.

“…it is also said that in Christ dwelt all the fullness of the Godhead bodily; but we understand that he became flesh, not just as he is said to dwell in the saints, but we define that that tabernacling in him was according to equality. But being made one in nature, and not converted into flesh, he made his indwelling in such a way, as we may say that the soul of man does in his own body.” - Council of Ephesus, Session I, The Epistle of Cyril to Nestorius

“Wherefore, we say that the two natures were united, from which there is the one and only Son and Lord, Jesus Christ, as we accept in our thoughts; but after the union, since the distinction into two is done away with, we believe that there is one physis [nature] of the Son, as one, however, one who became man and was made flesh. But if being God the Word he is said to be incarnate and to be made man, let the suspicion of a change be cast somewhere far away, for he has remained what he was, and let the entirely unconfused union be confessed on our part.” - St Cyril of Alexandria, Letter 40:14

“For how will anyone divide walking upon the water? For to run upon the sea is foreign to the human nature, but it is not proper to the divine nature to use bodily feet. Therefore that action is of the incarnate Word, to whom belongs at the same time divine character and human, indivisibly.” - St Severus of Antioch

Nestorius praises Pope St Leo:
And God brought not these things about on my account. For who is Nestorius? Or what is his life? Or what is his death in the world? But [he has brought them to pass] because of the truth which he has given unto the world, which was suppressed from deceitful causes, while he has also confuted the deceivers. And because they were [filled] with suspicion about me and were not believing what I was saying, as one that dissembles the truth and represses exact speech, God appointed for this [purpose] a preacher who was guiltless of this suspicion, Leo, who used to preach the truth undaunted. And, because the anticipation of the Council caused many to wonder and even the Romans themselves, [so] that they believed not the things which I was saying and which were left without examination, God allowed these things to come to pass contrariwise, that he might cause the bishop of Rome, who was exercising the direction of the plotting of the Council in Ephesus against me, to pass away, and [that] he might make him agree with and confirm what was said by the bishop of Constantinople. - Nestorius of Constantinople, The Bazaar of Heracleides, Book II, Part II

 

[Vico]

Eastern Orthodox Fr. Romanides explains some terminology which can be helpful in understanding:
In both the Cappadocian and Alexandrian traditions the ousia of God is beyond all categories of thought in a radical manner and therefore not only beyond definition of any kind, but also beyond the predication of any name whatsoever, to such an extent that God is hyper-onymos, hyper-ousios and even hyper-theos. Within this Biblical tradition the ousia of man also remains a mystery. Only the energies and rowers of both God and man can be known. In this sense the term ousia is used not in the Greek philosophical sense of the definable and knowable immutable inner reality of a thing, but as concrete unknowable reality known only in its acts. In contrast to the Antiochene and Latin tradition (the Augustinian one), the term ousia as applied to the Holy Trinity by the Cappadocian and Alexandrian Fathers is neither a platonic superstratal genus, nor an Aristotelian substratal material in which the hypostases or persons of the Holy Trinity participate. Therefore, Christ being in two ousiai could only mean that our Lord, the Only-Begotten Son of God, exists in two concrete, yet undefinable and perfect and complete realities, each of which is by nature proper to Himself and distinguishable in the union in thought alone. The term in two natures is of Latin provenance and was translated by the Cappadocian oriented Fathers of Chalcedon by the phrase in two physeis. Under more normal conditions the Alexandrians might have accepted the term in their own theological language as in two ousiai. It is only in this anti-Eutychian sense that the non-Chalcedonians must understand the term in two physeis whose only intent is to preclude one ousia after the union.
romanity.org/htm/rom.08.en.st._cyrils_one_physis_or_hypostasis_of_god_the_log.htm
At Chalcedon, Session II the three statements of Pope St. Leo that sounded Nestorian were challenged when read, but defended with passages from St. Cyril.

fordham.edu/halsall/basis/chalcedon.asp
newadvent.org/fathers/3811.htm

Also see: Mansi VI, 972 and 973.

Note at the end of Session II, after reading the The Tome of St. Leo and "a long catena of quotations from the Fathers sustaining the teaching of the Tome":After the reading of the foregoing epistle, the most reverend bishops cried out: This is the faith of the fathers, this is the faith of the Apostles. So we all believe, thus the orthodox believe. Anathema to him who does not thus believe. Peter has spoken thus through Leo. So taught the Apostles. Piously and truly did Leo teach, so taught Cyril. Everlasting be the memory of Cyril. Leo and Cyril taught the same thing, anathema to him who does not so believe. This is the true faith. Those of us who are orthodox thus believe. This is the faith of the fathers. Why were not these things read at Ephesus *? These are the things Dioscorus hid away.
*