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: 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. Thoughts of resolution 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". On 20 May 1973, Pope Shenouda III of Alexandria and Pope Paul VI jointly declared: 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: 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 "divine and human natures": Similar accords were signed by the head of the Catholic Church and the heads of the Syriac Orthodox Church and the Armenian Apostolic Church. Although unofficial dialogue between individual theologians of the (Eastern) Orthodox and the Oriental Orthodox began in 1964,