Miaphysitism is the Christological doctrine upheld by the Oriental Orthodox Churches, who include the Ethiopian Orthodox Tewahedo Church, Eritrean Orthodox Tewahedo Church, Coptic Orthodox Church of Alexandria, the Syriac Orthodox Church and the Armenian Apostolic Church. Rather than using the wording established at the Council of Chalcedon (451) that Jesus is one "person" (in Greek ὑπόστασις hypostasis) in two "natures" (in Greek φύσεις physeis), a divine nature and a human nature, they hold that Jesus, the "Incarnate Word, is fully divine and fully human, in one physis." In modern times, these differences are considered to be in word rather than in belief.
The 451 Council of Chalcedon used physis to mean "nature" (as in "divine nature" and "human nature"), and defined that there was in Jesus one hypostasis (person) but two physeis (natures). It is disputed whether Cyril used physis in that sense. John Anthony McGuckin says that in Cyril's formula "physis serves as a rough semantic equivalent to hypostasis".
Others interpret the Miaphysite term physis in line with its use by the Council of Chalcedon and speak of "Miaphysitism" as "Monophysitism", a word used of all forms of denial of the Chalcedonian doctrine. However, they add that "Miaphysitism" is "the more accurate term for the position held by the Syrian, Coptic and Armenian Churches".
The broad term "Dyophysitism" covers not only the Chalcedonian teaching but also Nestorianism interpreted as meaning that Jesus is not only of two natures but is in fact two centres of attribution, and thus two persons, a view condemned by the Council of Chalcedon. Similarly, "Monophysitism" covers not only Oriental Orthodox teaching but also the view called Eutychianism, according to which, after the union of the divine and human natures in the incarnation of the eternal Son or Word of God, he has only a single "nature", a synthesis of divine and human, identical with neither. This doctrine the Miaphysites reject, teaching instead that the incarnate Christ has one "nature", but one that is still of both a divine character and a human character and retains all the characteristics of both, with no mingling, confusion (pouring together) or change of either nature.
To avoid being confused with Eutychians, the Oriental Orthodox Churches reject the label "Monophysite". Coptic Metropolitan Bishoy of Damiette declared it a misnomer to call them Monophysites, for "they always confessed the continuity of existence of the two natures in the one incarnate nature of the Word of God. Non[e] of the natures ceased to exist because of the union and the term 'Mia Physis' denoting the incarnate nature is completely different from the term 'Monophysites'. [...] The Oriental Orthodox do not believe in a single nature in Jesus Christ but rather a united divine-human nature."
The Agreed Statement by the Anglican-Oriental Orthodox International Commission in 2014 said: "The term 'monophysite', which has been falsely used to describe the Christology of the Oriental Orthodox Churches, is both misleading and offensive as it implies Eutychianism. Anglicans, together with the wider oikumene, use the accurate term 'miaphysite' to refer to the Cyrilline teaching of the family of Oriental Orthodox Churches, and furthermore call each of these Churches by their official title of 'Oriental Orthodox'. The teaching of this family confesses not a single nature but one incarnate united divine-human nature of the Word of God. To say 'a single nature' would be to imply that the human nature was absorbed in his divinity, as was taught by Eutyches."
The conflict over terminology was to some extent a conflict between two renowned theological schools. The Catechetical School of Alexandria focused on the divinity of Christ as the Logos or Word of God and thereby risked leaving his real humanity out of proper consideration (cf. Apollinarism). The stress by the School of Antioch was on the humanity of Jesus as a historical figure. To the theological rivalry between the two schools was added a certain political competitiveness between, on the one hand, Alexandria and, on the other, Antioch and Constantinople.
The condemnation of Nestorius at the Council of Ephesus in 431 was a victory for the Alexandrian school and church, but its acceptance required a compromise, the "Formula of Reunion", entered into by Cyril of Alexandria and John of Antioch two years later. Cyril died in 444. Under his successor, Dioscurus I of Alexandria, a Constantinopole-based archimandrite named Eutyches, whose answer to questions put to him was judged heretical by Bishop Flavian of Constantinople, in turn accused Flavian of heresy. The Emperor convoked a council and entrusted its presidency to Dioscurus. This Second Council of Ephesus, held in 449, rehabilitated Eutyches and condemned and deposed Flavian and some other bishops. These appealed to Pope Leo I, who, calling their assembly not a concilium but a latrocinium, a robber council rather than a proper council, declared it null and void. The Miaphysite Churches still recognize it as valid, but outside their ranks it is not reckoned as an ecumenical council.
The Council of Chalcedon was held in 451 and annulled that presided over by Dioscurus. It has not been accepted by the Oriental Orthodox Churches, who do not defend Eutyches and accept the implicit condemnation of him by the (non-ecumenical) Third Council of Ephesus held in 475.
The Council accepted by acclamation Leo's Tome, the letter by Pope Leo I setting out, as he saw it, the Church's doctrine on the matter, and issued what has been called the Chalcedonian Definition, of which the part that directly concerns Miaphysitism runs as follows:
Following, then, the holy Fathers, we all unanimously teach that our Lord Jesus Christ is to us One and the same Son, the Self-same Perfect in Godhead, the Self-same Perfect in Manhood; truly God and truly Man; the Self-same of a rational soul and body; co-essential with the Father according to the Godhead, the Self-same co-essential with us according to the Manhood; like us in all things, sin apart; before the ages begotten of the Father as to the Godhead, but in the last days, the Self-same, for us and for our salvation (born) of Mary the Virgin Theotokos as to the Manhood; One and the Same Christ, Son, Lord, Only-begotten; acknowledged in Two Natures unconfusedly, unchangeably, indivisibly, inseparably; the difference of the Natures being in no way removed because of the Union, but rather the properties of each Nature being preserved, and (both) concurring into One Person and One Hypostasis; not as though He was parted or divided into Two Persons, but One and the Self-same Son and Only-begotten God, Word, Lord, Jesus Christ; even as from the beginning the prophets have taught concerning Him, and as the Lord Jesus Christ Himself hath taught us, and as the Symbol of the Fathers hath handed down to us.
Dissent from this definition did not at first lead to a clean break between what are now the Eastern Orthodox Church and the Oriental Orthodox Churches. While in the West Rome tended to uphold steadfastly the text of Leo's Tome and of the Chalcedonian definition, the situation in the East was fluid for a century after the council, with compromise formulas imposed by the emperors and accepted by the Church and leading at times to schisms between East and West (cf. Acacian Schism, Henotikon, Monoenergism).
The situation then hardened into a fixed division between what are now called the Oriental Orthodox Churches and the Chalcedonian Churches later divided into the Eastern Orthodox Church and the Catholic Church and its Protestant derivations.
Towards a resolution of the dispute?
In recent decades a number of Christological agreements between Miaphysite and Chalcedonian Churches have been signed not just by theologians but by heads of Churches. They explicitly distinguish the divinity and the humanity of Christ, without necessarily using the phrase "two natures".
We confess that our Lord and God and Saviour and King of us all, Jesus Christ, is perfect God with respect to His Divinity, perfect man with respect to His humanity. In Him His divinity is united with His humanity in a real, perfect union without mingling, without commixtion, without confusion, without alteration, without division, without separation. His divinity did not separate from His humanity for an instant, not for the twinkling of an eye. He who is God eternal and invisible became visible in the flesh, and took upon Himself the form of a servant. In Him are preserved all the properties of the divinity and all the properties of the humanity, together in a real, perfect, indivisible and inseparable union.
At that meeting they decided to set up an official theological dialogue between the two Churches. On 12 February 1988 the commission that carried on that dialogue signed "a common formula expressing our official agreement on Christology which was already approved by the Holy Synod of the Coptic Orthodox Church on 21 June 1986". The brief common formula was as follows:
We believe that our Lord, God and Saviour Jesus Christ, the Incarnate-Logos, is perfect in His Divinity and perfect in His Humanity. He made His Humanity one with His Divinity without mixture nor mingling, nor confusion. His Divinity was not separated from His Humanity even for a moment or twinkling of an eye. At the same time, we anathematize the doctrines of both Nestorius and Eutyches.
A "Doctrinal Agreement on Christology" was signed on 3 June 1990 by Baselios Mar Thoma Mathews I, Catholicos of the Malankara Orthodox Syrian Church and Pope John Paul II, in which they explicitly spoke of "natures" in the plural:
Our Lord Jesus Christ is one, perfect in his humanity and perfect in his divinity – at once consubstantial with the Father in his divinity, and consubstantial with us in his humanity. His humanity is one with his divinity – without change, without commingling, without division and without separation. In the Person of the Eternal Logos Incarnate are united and active in a real and perfect way the divine and human natures, with all their properties, faculties and operations. [...] It is this faith which we both confess. Its content is the same in both communions; in formulating that content in the course of history, however, differences have arisen, in terminology and emphasis. We are convinced that these differences are such as can co-exist in the same communion and therefore need not and should not divide us, especially when we proclaim Him to our brothers and sisters in the world in terms which they can more easily understand.
Although unofficial dialogue between individual theologians of the (Eastern) Orthodox and the Oriental Orthodox began in 1964, official dialogue did not begin until 1985; but already by 1989 an agreement was reached on the Christological dogma, stating that the word physis in Cyril of Alexandria's formula referred to the hypostasis of Christ, one of the three hypostaseis or prosopa (persons) of the Trinity, who has "become incarnate of the Holy Spirit and Blessed Virgin Mary Theotokos, and thus became man, consubstantial with us in His humanity but without sin. He is true God and true Man at the same time, perfect in his Divinity, perfect in His humanity. Because the one she bore in her womb was at the same time fully God as well as fully human we call the Blessed Virgin Theotokos. When we speak of the one composite hypostasis of our Lord Jesus Christ, we do not say that in Him, a divine hypostasis and a human hypostasis came together. It is that the one eternal hypostasis of the Second Person of the Trinity has assumed our created human nature in that act uniting it with His own uncreated divine nature, to form an inseparably and unconfusedly united real divine-human being, the natures being distinguished from each other in contemplation only."
A second Agreed Statement was published in the following year 1990 declaring:
The Orthodox agree that the Oriental Orthodox will continue to maintain their traditional Cyrillian terminology of “one nature of the incarnate Logos” (μία φύσις τοῦ θεοῦ λόγου σεσαρκωμένη), since they acknowledge the double consubstantiality of the Logos which Eutyches denied. The Orthodox also use this terminology. The Oriental Orthodox agree that the Orthodox are justified in their use of the two-natures formula, since they acknowledge that the distinction is “in thought alone” (τῇ θεωρίᾳ μόνῃ). [...] we have now clearly understood that both families have always loyally maintained the same authentic Orthodox Christological faith, and the unbroken continuity of the apostolic tradition, though they have used Christological terms in different ways. It is this common faith and continuous loyalty to the Apostolic Tradition that should be the basis for our unity and communion.
Implementation of the recommendations of these two Agreed Statements would mean restoration of full communion between the Eastern Orthodox and the Oriental Orthodox Churches, but as of 2020 they have not been put into effect. Of the Eastern Orthodox Churches, only the patriarchates of Alexandria, Antioch and Romania have accepted the Statements, as have the Coptic, Syriac and Malankara Churches on the Oriental Orthodox side. The Russian patriarchate has asked for clarification of some points. The monastic community of Mount Athos rejects any form of dialogue. Others have taken no active interest.
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