Some folks seem to find relying on councils a comfort. For these folks, there are some inconvenient facts that they must face. This post is the twentieth in the multi-part series.
The First Councils of Ephesus (A.D. 431) / Third Ecumenical Councils
That pluralization is not a typo. You may have heard of the first council of Ephesus, also called the Third Ecumenical Council. It was held in Ephesus in 431. What tends not to be mentioned is this:
Who Called the Council(s)?
If you guessed, "the pope," or less anachronistically "the bishop of Rome," you would be wrong. The person who called the council was Theodosius II. It was not initiated by "the Church" but by the state.
Was the Council Fair? And why do you keep pluralizing Council?
Again, if this is a Holy Council of the universal church, specially blessed by the Holy Spirit, one might expect that it would be a fair council. It was not - or at least it gives the strong appearance of being unfair. Cyril of Alexandria headed up one faction that responded to Theodosius II's call for the council. He arrived in Ephesus in advance of his theological opponents. When he learned that they were several days away, he went ahead and opened the council. His opponents arrived four days later and convened their own council in Ephesus. Each side deposed the other side.
In the short term, Cyril's party won. There was a rift between the parties of the rival parties, but the rift between the parties was resolved. In the long term, his leading opponent (Nestorius) remains synonymous with division of Christ into two persons, whether or not Nestorius actually held that view. On the other hand, phrases attributed to Cyril, such as "one nature after the union," were later condemned by Chalcedon (A.D. 451), vindicating the opposing party to some degree.
Eastern Orthodox historian Meyendorff agrees:
The Chalcedonian definition of 451—two natures united in one hypostasis, yet retaining in full their respective characteristics—was therefore a necessary correction of Cyril’s vocabulary. Permanent credit should be given to the Antiochians—especially to Theodoret—and to Leo of Rome for having shown the necessity of this correction, without which Cyrillian Christology could easily be, and actually was, interpreted in a Monophysite sense by Eutyches and his followers.- John Meyendorff, Byzantine Theology: Historical Trends and Doctrinal Themes, 2nd rev. ed. (New York: Fordham University Press, 1983), p. 33.
How was the Rift Resolved?
The rift was resolved by the adoption (without the mechanism of a council) of the Formula of Union. This formula condemned Nestorius, but forced Cyril to back off from the stand taken in his Twelve Anathemas. It resulted in a tottering peace, and that peace fell apart after Cyril's death (A.D. 444), arguably due to the ferocity of Dioscorus, one of the leaders among those who were in Cyril's party.
Norman Russell, an historian who I believe is Anglican (I'm not sure), explains:
The ‘precise facts’, although Cyril does not say so, are that the Formulary of Reunion  was the best compromise that he could have secured in these circumstances. The repudiation of Ephesus by the Eastern bishops under the leadership of John of Antioch meant that the council would have failed unless the Easterners could have been persuaded to accede to it retrospectively. And the power diplomacy exercised by the imperial commissioner Aristolaus, backed up by the menacing presence of the magistrianos Maximus, made it clear to Cyril what the alternatives were: doctrinal agreement between Alexandria and Antioch or the setting aside of the Council with the possible restoration of Nestorius and the certain banishment of Cyril. It is no wonder that Cyril suffered bouts of nervous depression before an accord was finally signed. The gloss that he put on the phraseology of the Formulary in his letter to Eulogius was that the ‘two natures’ refers to the Word and the flesh, for neither becomes the other as a result of the Incarnation. But the ‘two natures’ in itself says nothing about the union. For this we need to refer to ‘one incarnate nature of the Son’. The ‘one nature’ from ‘two natures’ is analogous to the formation of a single human being from the two constituent natures of body and soul. The words ‘one’ and ‘two’ in Cyril’s usage refer to two different levels of reality.Norman Russell, his chapter in The Theology of St Cyril of Alexandria: A Critical Appreciation (London: T & T Clark, 2003), pp. 238-240.
Cyril returned to this argument in greater detail in his First Letter to Succensus. Succensus, one of Cyril’s allies, although bishop of Diocaesarea in the territory of John of Antioch, had asked Cyril ‘whether one should ever speak of two natures in respect of Christ’. In reply Cyril rehearses the teaching of Nestorius, which he claims was derived from Diodore of Tarsus. The ‘twoness’ for Nestorius, as Cyril understood it, consisted in a man being joined to the Word in a nominal sense, so that man and the Word enjoyed a deemed equality by honour or rank. The assigning of different sayings in the Gospels either to the humanity or to the divinity is symptomatic of such an approach. The correct doctrine, by contrast, is that Christ is the pre-eternal Word born of the Virgin. Cyril knows that he is accused of Apollinarianism for teaching this. A strict union is in danger of being seen as a merger [σύνχσις], mixture [σύνκρασις] or mingling [φυρμός]. Cyril rebuts the slander. What we affirm, he says, is that the Word from God the Father united to himself a body endowed with a soul without merger [ἀσυνχύτως], alteration [ἀτρέπτως] or change [ἀμεταβλήτως]. It is necessary to maintain the two natures (i.e., the composite elements, the divine and the human, that make up Christ) as well as the one nature (i.e., the single subject who is the Son — ‘the one incarnate nature of the Word’). If either is missing our Christology cannot be orthodox.
It would perhaps have prevented a great deal of subsequent misunderstanding if Cyril could have gone one step further and made his second meaning of physis explicitly equivalent to hypostatis. Cyril accepted the Cappadocian identity of ousia in three separate hypostaseis on the Trinitarian level. But it was not until Chalcedon that an analogous distinction was applied to Christology: two natures but one hypostatis or prosopon. The reason why Cyril could not take that step was his conviction that the mia physis formula had been sanctioned by Athanasius, the church father so far as Cyril was concerned, In fact the phrase ‘one incarnate nature of God the Word’ had been devised by Apollinarius, who had put it forward in the statement of faith he sent to the Emperor Jovian in 363. This statement had been reassigned to Athanasius by Apollinarius’ disciples after his condemnation. Cyril was completely taken in by the forgery. He first used the mia physis formula in his five-volume polemic against Nestorius, and again in his important dogmatic letters to Eulogius and Succensus. To him it was a useful phrase of irreproachable provenance which emphatically ruled out Nestorius’ loose ‘prosopic union’ once and for all.
But Did Chalcedon Contradict Ephesus?
Canon 7 of the Council of Ephesus states: "These things having been read aloud, the holy Council then decreed that no one should be permitted to offer any different belief or faith, or in any case to write or compose any other, than the one defined by the Holy Fathers who convened in the city of Nicaea, with Holy Spirit."
Yet, quite famously, the Council of Chalcedon (A.D. 451) did write and compose another creed than that of Nicaea. The modified creed is still called the "Nicene Creed," but is more suitably referred to as as the "Nicene-Constantinoplean Creed" (such a mouthful, it is easy to see why the more imprecise description is popular).
This was also a vindication for those of the party that had convened a council with Nestorius. After all, one of Dioscorus' attacks on them was that the Formula of Union was essentially a supplemental creed beyond that of Nicaea, yet Chalcedon felt free to come up with a new creed - one that largely adopted the views of the Formula of Union.
Have you left out a council?
Yes, I left out another council that met in A.D. 449 in Ephesus. This council condemned the author of the Formula of Union and vindicated Eutychius, rejecting the arguments from Leo I (of Rome), and exonerated Eutychius. This council was also called by Theodosius II. Nevertheless, it was overturned by the council of Chalcedon in 451.
What Explains the Reversal?
Well, God's Providence is certainly one explanation. But another, more to-the-point explanation, is that in July 450 Theodosius II fell off his horse and died. His sister Pulcheria was closely allied with Leo of Rome, in contrast to Chrysaphius, who had been running imperial affairs under Theodosius II, and who was allied with Eutychius. Pulcheria called the council of Chalcedon in 451, after having Chrysaphius executed and Eutychius exiled. From a human standpoint, Pulcheria controlled the council, and the result was just as she wished: Dioscorus was condemned and exiled, and Leo's "Tome" (previously rejected de facto at Ephesus II, A.D. 449) was given a prominent place.
Eastern Orthodox historian John A. McGuckin, who has a very high view of Cyril, would disagree with my assessment:
But this, nothing else, is what the Chalcedonian text teaches, at least when it is read apart from the Leonine Tome, which has too often been taken as its exegetical commentary, but rather should be taken out of the interpretive picture since the Chalcedonian symbol was more in the manner of a corrective of Leo than a substantiation of him. This can be seen nowhere more clearly than in the verbal form which drives that whole central clause containing the four adverbs qualifying ‘in two natures’. It is none other than ‘Gnorizomenon’: ‘made known to the intellect.’ Chalcedon, therefore, teaches that Christ is ‘made known (to the intellect) in two natures’. It does not simply teach that ‘Christ is in two natures’ as the Antiochene system had suggested. Those who do not recognize or understand the importance of the difference are those who have not followed the whole fifth century Christological debate, but this certainly did not include the bishops present at Chalcedon. And so, the Chalcedonian decree, at this critical juncture, is clearly and deliberately, a profession of Cyril’s understanding of the union and, again, largely on his terms. The ‘made known’ of Chalcedon is substantially the ‘notional scrutiny’ (oson men heken eis ennoian) of Cyril’s First Letter to Succensus. Even when Cyril’s terminology was felt to be in need of correction, or clarification, whether to placate the West, or to exclude a Eutyches or a Dioscorus, it was instinctively to Cyril that they turned to supply the correction.- John A. McGuckin, St. Cyril of Alexandria: The Christological Controversy, Its History, Theology and Texts (Leiden: E. J. Brill, 1994 ), p. 240.