When Sisinnius the Patriarch of Constantinople died, the Emperor Theodosius II decided not to appoint anyone from the rival factions in Constantinople. Instead, he appointed an outsider, Nestorius, who had been living as a priest and monk in the monastery of Euprepius near Antioch. He had a reputation for asceticism, orthodoxy and eloquent sermons. According to Socrates Scholasticus, during his ordination sermon on April 10^th, 428, Nestorius addressed the Emperor, saying: “Give me, my prince, the earth purged of heretics, and I will give you heaven as a recompense. Assist me in destroying heretics, and I will assist you in vanquishing the Persians.” He attempted to make good on his promise but would be deposed from his office in three years as a heretic himself.

Five days after his ordination Nestorius demolished a chapel where Arians (whose beliefs had been anathematized at the 325 Council of Nicea) worshipped. Outraged by this, the Arians set their demolished chapel on fire, which resulted in burning many adjacent buildings to the ground. From that time Nestorius was seen as a firebrand. “For he could not rest, but seeking every means of harassing those who embraced not his own sentiments, he continually disturbed the public tranquility.” He antagonized Memnon, the bishop of Ephesus, by pursuing heretics into Ephesian ecclesiastical districts. Socrates Scholastiicus’ astute observation was: “Nestorius indeed acted contrary to the usage of the Church, and caused himself to be hated in other ways also.”

Around this time, an associate Nestorius brought with him from Antioch, a presbyter names Anastasius, preached a sermon and said: “Let no one call Mary Theotókos [mother of God], for Mary was but a woman, and it is impossible that God should be born of a woman.” These words caused a great turmoil among both the laity and the clergy, who saw Anastasius as separating the humanity of Christ from his divinity. Seeking to support his friend and associate, Nestorius preached several sermons also rejecting the epithet Theotókos. The resultant discussion divided the church “and resembled the struggle of combatants in the dark, all parties uttering the most confused and contradictory assertions.” Nestorius was understood to be asserting “the blasphemous dogma that the Lord is a mere man.”

It was the opinion of Socrates Scholastiicus that Nestorius was “an unlearned man” who seemed to be terrorized by the term Theotókos. “The fact is, the causeless alarm he manifested on this subject just exposed his extreme ignorance: for being a man of natural fluency as a speaker, he was considered well educated, but in reality he was disgracefully illiterate.” Socrates noted how Nestorius seemed ignorant of 1 John 4:2-3, thinking that he did not need to “give his attention to the ancients.” This failure to know the Scriptures led to his downfall, as he and his followers mutilated the passage in their attempts to separate the manhood of Christ from his deity. “This idle contention of his has produced no slight ferment in the religious world.”

This played right into the hands of his political and theological rival, Cyril, bishop of Alexandria. Cyril wrote a series of letters to Nestorius, urging him to stop preaching against Mary as Theotókos. Cyril said if Nestorius rejected the personal union of Jesus Christ, as confessed in the 325 Creed of Nicea (i.e., “begotten from the Father”; “only-begotten”; “who came down and became incarnate”), “we fall into the error of making two sons.” Cyril charged Nestorius with misinterpreting the Creed of Nicea and urged him “to hold to the universal teaching of both East and West.” But Nestorius would not back down from what he preached. Cyril advised Pope Celestine to condemn the teachings of Nestorius, who agreed saying:

 … If he, Nestorius, persists, an open sentence must be passed on him, for a wound like this, when it affects not one member only, but rends the whole body of the Church, must be cut away at once. . . . And so, appropriating to yourself the authority of our see, and using our position, you shall with resolute severity carry out this sentence, that either he shall within ten days, counted from the day of your notice, condemn in writing this wicked preaching of his, and shall give assurance that he will hold, concerning the birth of Christ our God, the faith which the Roman Church and the Church of your Holiness and universal religion holds; or if he will not do this (your Holiness having at once provided for that Church) he will know that he is in every way removed from our body as not being willing to accept the care lavished on him by those wishing to heal him, and as hastening on a destructive course to his own perdition and to the perdition of all entrusted to him.

But Nestorius has already arranged with the Emperor Theodosius II to assemble a council before the condemnation from the pope arrived. The Emperor Theodosius II (408-50) called for the Council of Ephesus to begin on Pentecost in 431. The Council was held in St. Mary’s Basilica in Ephesus, where the theotókos formula was popular. St. Mary’s was known for its veneration of Mary,

Referring to Mary as Theotókos, meaning “God-bearer” or “Mother of God” had a long and uncontroversial history before the dispute between Nestorius and Cyril. Affirming that Mary gave birth to the human Jesus self evidently meant affirming she gave birth to the divine Jesus. Basil the Great (330-379) expressed this idea in his Letter 360:

According to the blameless faith of the Christians which we have obtained from God, I confess and agree that I believe in one God the Father Almighty; God the Father, God the Son, God the Holy Ghost; I adore and worship one God, the Three. I confess to the œconomy of the Son in the flesh, and that the holy Mary, who gave birth to Him according to the flesh, was Mother of God [Theotókos].

In one his letters to Nestorius Cyril said the qualification of the virgin Mary as Theotókos was not a problem because it does not signify the divine nature of the Logos as having a beginning. Rather, it asserts that the incarnation of the Logos needed to assume the human condition through the virgin. In other words, the hypostasis of the Logos makes the divine motherhood of Mary possible because the Son who she carries and is truly born of her in the second person of the Trinity. Cyril said:

The holy fathers do not hesitate to call the holy Virgin Theotókos, not in the sense that the divine nature of the Word took its origin from the holy Virgin, but in the sense that he took His holy body, gifted with a rational soul from her. Yet, because the Word is hypostatically united to this body, one can say that he was truly born according to the flesh. 

Nestorius was opposed to calling Mary the Theotókos because he believed Mary could not be the mother of God since the Trinitarian God is infinite and eternal, “so no human being can be the mother of God.” Nestorius thought affirming Mary as Jesus’ mother could only be applied to the human nature of Jesus, and not the divine person of the Logos. Therefore, it was more appropriate to call Mary anthropotokos, meaning “man-bearer” or Christotokos, meaning “Christ-bearer.” Nestorism made a clear distinction between the human and divine natures in Christ, “denying any real organic union between the man Jesus and the indwelling divine Logos.”

Orthodox believers saw this as saying that while there was one Son and one Christ in two natures, their union was little more than a moral union of two distinct beings. What was missing was the Divine Personality of Christ. Cyril of Alexandria challenged, “If our Lord Jesus Christ is God, how can it be that the Holy Virgin, who gave birth to Him is not the Mother of God?” At stake in this debate was the divinity of Christ. According to David Christie-Murray, if Nestorius’ doctrine had been adopted as orthodox, Christ would have eventually been seen as a mere man, inspired by the indwelling of the divine Logos.

With the support of Memnon, the bishop of Ephesus, Cyril of Alexandria opened the Council on June 22, 431, without waiting for the arrival of the Antiochene (pronounced An-tie-o-kene) Syrian bishops, who formed the party most likely to be supportive of Nestorius. The decision made by Cyril and those who were in attendance was to depose Nestorius from his see in Constantinople and excommunicate him. Nestorians doctrines were condemned. Significantly, the Council of Ephesus did not formulate a new creed. Rather, it reaffirmed the Nicene Creed, stating: “No one shall be permitted to introduce, write, or compose any other faith, besides that which was defined by the holy fathers assembled in the city of Nicea, with the presence of the Holy Ghost.”

When the Syrian bishops arrived four days later, they met with Theodoret, an influential theologian of the time who was a supporter of Antiochene Christology. Along with other representatives at the Council who objected to Cyril’s actions, they held a rival meeting at which they excommunicated Cyril and Memnon.

The ecclesiastical and theological rivalry between Cyril and Nestorius reflected the competing Christologies of the School of Alexandria and Antioch. The Oxford Dictionary of the Christian Church said the Alexandrians emphasized: “In Christ God Himself was living a human life.” They saw the affirmation of this paradoxical self-effacement as evidence of God’s deep love for humanity. The Antiochenes (from Antioch) emphasized how in Christ both humanity and divinity co-operated; and that such a conjunction of human and divine did not encroach upon the reality of either of the two natures.

According to the New Dictionary of Theology, the Catechetical School of Alexandria (or the Didascalium) was an early center for higher Christian learning, founded in the mid-second century under early church leaders such as Clement and Origen. It became a leading center of the allegorical method of biblical interpretation and had a tendency to emphasize the divinity in Christ. Athansius was also associated with the Alexandrian School. Origin provided for the divine nature of the Father, Son and Holy Spirit, while still making distinctions between the three. “Athansius emphasized their unity as one God.”

Cyril opposed the Antiochene division between the human and divine in Christ by insisting on the unity of his person. The term theotókos had been used in Alexandria to refer to Mary long before Cyril made it a watchword of his opposition to Nestorius. Cyril and the Alexandrians saw their stress on the unity of the incarnate Word as a crucial defense of the Nicene Creed and a refutation of Arianism. “Although safeguarding the unity of Christ’s person, the Alexandrian approach led to Monophysitism, which appealed to Cyril as its chief theological mentor.”

Antiochene theology was associated with the church and School at Antioch whose exegetical methods and theology contrasted with Alexandrian theology. In scriptural exegesis, it placed more emphasis on the literal and historical sense of the text, while still stressing the importance of the deeper, spiritual meaning. It developed largely in reaction to Arianism in the 4^th and 5^th centuries. In its Christology, it stressed the humanity of Christ and the reality of His moral choices. “To achieve this, and to preserve the impassibility of His Divine nature, the unity of His person was described in a looser way than in Alexandrian theology.” This difference and the mutual suspicion to which it gave rise, was the theological foundation of the controversy. However, Nestorian dogma was more radical than most other Antiochenes were willing to go.

Reconciliation with Cyril and the more moderate Antiochenes was finally effected in 433. The council passed eight canons, in which the Pelagian Celestius and Nestorius were (again) condemned. In its rejection of Nestorianism, the Council gave formal approval to the title Theotókos for Mary. Theodosius II eventually acquiesced to its decision and Nestorius was sent back to his monastery at Antioch. In 435 Theodosius condemned his books and in 436 Nestorius was banished to a monastery Upper Egypt, within the diocese of Cyril, where he died in 351.

Information on the creeds and heresies discussed here was taken primarily from Early Christian Creeds and Early Christian Doctrines by J. N. D. Kelly; A History of Heresy by David Christie-Murray; the New World Encyclopedia entry on “Nestorius;” The Ecclesiastical History by Socrates Scholasticus, the Oxford Dictionary of the Christian Church and Creeds, Councils, Controversies by James Stephenson. For more on the early creeds and heresies of the Christian church, see the link: “Early Creeds.”