The Church of the East was associated with the doctrine of Nestorianism, advanced by Nestorius, Patriarch of Constantinople from 428 – 431, which emphasized the disunion between the human and divine natures of Jesus.

Nestorius ' doctrine, Nestorianism, which emphasized the disunity between Christ's human and divine natures, had brought him into conflict with other church leaders, most notably Cyril, Patriarch of Alexandria.

Nestorius tried to find a middle ground between those that emphasized the fact that in Christ God had been born as a man, insisted on calling the Virgin Mary Theotokos ( Greek: Θεοτόκος, " God-bearer "), and those that rejected that title because God as an eternal being could not have been born.

The conflict between the two bishops is described by historian Averil Cameron, " The issue was whether, and, if so, how, Christ had two natures ; the Monophysites held that he had only a divine nature, while Nestorius, and ' Nestorians ' after him, emphasized the human " Nestorius was an advocate of diminishing the influence of the Mother of God, or Theotokos, from the Church.

Nestorius and his doctrine, which emphasized the distinctness between Christ's human and divine natures, were condemned at the First Council of Ephesus in 431 and the Council of Chalcedon.

Nestorianism has come to mean dyaphysitism, in which Christ's dual natures are eternally separate, though it is doubtful whether Nestorius ever taught such a doctrine.

Nestorius argued that Mary was neither a " Mother of Man " nor " Mother of God " as these referred to Christ's two natures ; rather, Mary was the " Mother of Christ ".

Nestorius was especially criticized by Cyril, Pope ( Patriarch ) of Alexandria, who argued that Nestorius ' teachings undermined the unity of Christ's divine and human natures at the Incarnation.

The purpose of the condemnation was to make plain that the Imperial, Chalcedonian ( that is, recognizing the hypostatic union of Christ as two natures, one divine and one human, united in one person with neither confusion nor division ) Church was firmly opposed to all those who had either inspired or assisted Nestorius, the eponymous heresiarch of Nestorianism — the proposition that the Christ and Jesus were two separate persons loosely conjoined, somewhat akin to adoptionism, and that the Virgin Mary could not be called the Mother of God ( Gk.

The Council condemned as heretical the Christology of Nestorius, whose reluctance to accord the Virgin Mary the title ' Theotokos ' (' God-bearer ' or ' Mother of God ') was taken as evidence that he believed two separate persons ( as opposed to two united natures ) to be present within Christ.

Nestorius ' rejection of the term Theotokos (' God-bearer ', or ' Mother of God ') has traditionally been held as evidence that he asserted the existence of two persons – not merely two natures – in Jesus Christ, but there exists no evidence that Nestorius denied Christ's oneness.

He demanded of Macedonius a declaration of his faith in writing ; Macedonius addressed a memorandum to the emperor insisting that he knew no other faith than that of the Fathers of Nicaea and Constantinople, and that he anathematized Nestorius and Eutyches and those who admitted two Sons or two Christs, or who divided the two natures.

In his struggle against Nestorius, St. Cyril explained the union between the divine and human natures of Christ as " inward and real without any division, change, or confusion.

Nestorius argued that Christ's human and divine natures were distinct, and was therefore against using the title Theotokos ( Mother of God ) for the Virgin Mary, instead preferring to call her Christotokos ( Mother of Christ ).

Christ, according to Nestorius, was the conjunction of the Godhead with his " temple " ( which Nestorius was fond of calling his human nature ).

Nestorius spoke of the distinct ' Jesus the man ' and ' the divine Logos ' in ways that Cyril thought were too dichotomous, widening the ontological gap between man and God in a way that some of his contemporaries believed would annihilate the person of Christ.

Nestorius developed his Christological views as an attempt to rationally explain and understand the incarnation of the divine Logos, the Second Person of the Holy Trinity as the man Jesus Christ.

Nestorius ' opponents found his teaching too close to the heresy of adoptionism – the idea that Christ had been born a man who had later been " adopted " as God's son.

Irenaeus the friend of Nestorius, with the cooperation of Theodoret, became bishop of Tyre, in spite of the protests of Dioscorus, Cyril's successor, who now turned specially against Theodoret ; and, by preferring the charge that he taught two sons in Christ, he secured the order from the court confining Theodoret to Cyrrhus.

Nestorius tried to answer a question considered unsolved: " How can Jesus Christ, being part man, not be partially a sinner as well, since man is by definition a sinner since the Fall ".

Consequently, Nestorius argued that the Virgin Mary should be called Christotokos, Greek for " Birth Giver of Christ ", and not Theotokos, Greek for " Birth Giver of God ".

If such a union of human and divine occurred, Nestorius believed that Christ could not truly be con-substantial with God and con-substantial with us because he would grow, mature, suffer and die ( which Nestorius argued God cannot do ) and also would possess the power of God that would separate him from being equal to humans.

If such a union of human and divine occurred, Nestorius believed that Christ could not truly be con-substantial with God and con-substantial with us because he would grow, mature, suffer and die ( which he said God cannot do ) and also would possess the power of God that would separate him from being equal to humans.

In the Bazaar, written towards the end of his life, Nestorius denies the heresy for which he was condemned and instead affirms of Christ " the same one is twofold " – an expression that some consider similar to the formulation of the Council of Chalcedon.

Nestorius ' earlier surviving writings, however, including his letter written in response to Cyril's charges against him, contain material that suggest that at that time he held that Christ had two persons.

One famous example is Nestorius, the Patriarch of Constantinople who so vigorously defended Jesus ' humanity that he undermined Jesus ' divinity ; A brief definition of Nestorian Christology can be given as: " Jesus Christ, who is not identical with the Son but personally united with the Son, who lives in him, is one hypostasis and one nature: human .".

The Archbishop of Constantinople — Nestorius, having asserted that Mary ought not to be referred to as the " Mother of God " ( Theotokos in Greek, literally " God-bearer "), was denounced as a heretic ; in combating this assertion of Patriarch Nestorius, Eutyches declared that Christ was " a fusion of human and divine elements ", causing his own denunciation as a heretic twenty years after the First Council of Ephesus at the 451 AD Council of Chalcedon.

According to Nestorius, all the human experiences and attributes of Christ are to be assigned to ' the man ', as a distinct personal subject from God the Word, though united to God the Word from the moment of his conception.

Nestorius suggested the title Christotokos ( Χριστοτόκος, " Christ-bearer "), but did not find acceptance on either side.

This began a series of letters between Cyril and Nestorius which gradually became more strident in tone.

The main issue that prompted this dispute between Cyril and Nestorius was the question which arose at the Council of Constantinople: What exactly was the being to which Mary gave birth?

Theodoret was determined to preserve the peace of the Church by seeking the adoption of a formula avoiding the unconditional condemnation of Nestorius, and toward the close of 434 strove earnestly for the reconciliation between the Eastern churches.

McGuckin cites the " innate rivalry " between Alexandria and Constantinople as an important factor in the controversy between Cyril of Alexandria and Nestorius.

Nestorius believed that no union between the human and divine were possible.

A number of bishops, who were undecided between Nestorius and Cyril, did not want to give Cyril, as one party in the dispute, the right to chair the meeting and decide the agenda ; however, they began to take Cyril's side for various reasons.

Nestorius believed that no union between the human and divine were possible.

Neither did he have any share, as was wrongly ascribed to him, in the First Council of Ephesus of 431, though, in consequence of disputes which arose in Armenia between the followers of Nestorius and the disciples of Acathius of Melitene and Rabbula, Isaac and his church did appeal to Constantinople and through Saint Proclus obtained the desired explanations.

Nonetheless, Eusebius must have gained some credit for his Contestatio and outspoken opposition to Nestorius, because at some point between 431 and 448 he was made bishop of Dorylaeum.

The subject is adapted to the liturgical feast of the day ; thus in the canticle for Christmas, the dialogue is between the Blessed Virgin and the Magi ; for the Annunciation, between Gabriel and Mary ; for the feast of Syrian Doctors, between Cyril and Nestorius, etc.

However, a number of churches, particularly those associated with the School of Edessa, supported Nestorius – though not necessarily his doctrine – and broke with the churches of the West.

The council also passed five canons condemning Nestorius and Caelestius and their followers as heretics and a sixth one decreeing deposition from clerical office or excommunication for those who did not accept the Council's decrees.

J. Barmby, Hormisdas made several demands: ( 1 ) The emperor should publicly announce his acceptance of the council of Chalcedon and the letters of Pope Leo ; ( 2 ) the Eastern bishops should make a similar public declaration, and in addition anathematize Nestorius, Eutyches, Dioscorus, Aelurus, Peter Mongus, Peter the Fuller, and Acacius, with all their followers ; ( 3 ) everyone exiled in this dispute should be recalled and their cases reserved for the judgment of the Apostolic See ; ( 4 ) those exiles who had been in communion with Rome and professed Catholicism should first be recalled ; and ( 5 ) bishops accused of having persecuted the orthodox should be sent to Rome to be judged.

* In 431 the Churches that accepted the teaching of the First Council of Ephesus ( which condemned the views of Nestorius ) classified as heretics those who rejected the Council's statements.

35 ), Anatolius publicly condemned the teachings not only of Eutyches, but also those of Nestorius, subscribing to the letters of Cyril against Nestorius and of Pope Leo I against Eutyches ( Leo, Epp.

He engaged to publicly anathematize Nestorius and all who thought with him on his return, and declared the identity of his doctrine with that agreed upon by John and Cyril, and that he accepted the decrees of Ephesus equally with those of Nicaea as due to the inspiration of the Holy Spirit.

Rabbula ( or Rabbulas ) was a bishop of Edessa from 411 to August 435, noteworthy for his opposition to the views of Theodore of Mopsuestia, as well as those of Nestorius.

Eusebius of Dorylaeum was a 5th-century bishop who spoke out against heretical teachings, especially those of Nestorius and Eutyches, during the period of Christological controversy.

These views, though opposite of those of Nestorius, were just as unorthodox.