"In the closed world of Byzantium," writes Dom Gregory Dicke, "after the sixth century not a single fresh movement of thought arose... Sleep began in the ninth century, and perhaps even earlier, in the sixth."[35] The Byzantine dogmatic disputes of the fourteenth century convincingly expose the falsity of such assertions. Of course, Gregory Palamas was not an innovative revolutionary, but firmly stood on the tradition of the past. Nevertheless, he was the primary creative theologian, and his writings testify to the fact that Orthodox theology did not lose its activity even after the eighth century and the Seventh Ecumenical Council.

Among the contemporaries of Gregory Palamas, Nicholas Cabasilas should be noted. Cabasilas is the author of the "Commentary on the Divine Liturgy", which has become a classic work on this topic in Orthodoxy, as well as a treatise on the sacraments "Life in Christ". Cabasilas's writings are marked by two characteristics: a lively sense of the person of Christ (who, in the words of Nicholas, is "nearer to us than our own soul"[36]) and an unfailing concentration on the sacraments. For Cabasilas, the mystical life is essentially life in Christ and in the sacraments. There may be a danger that mysticism will assume an individualistic and speculative character, but in Cabasilas it always remains Christocentric, sacramental, ecclesiastical. The writings of Cabasilas show how closely mysticism and sacramental life are connected in Byzantine theology. Palamas and his entourage never believed that mystical prayer made it possible to dispense with a normal, institutionalized church life.

The second council on the question of union was held in Florence in 1438-1439, which was personally attended by Emperor John VIII (reigned 1425-1448), together with the Patriarch of Constantinople and a large delegation of the Byzantine Church, as well as representatives of other Orthodox churches. The discussions were lengthy, and both sides made great efforts to reach a genuine agreement on the main issues. At the same time, it was difficult for the Greeks to discuss theological problems impartially: they knew that their political situation was desperate and that the only hope of defeating the Turks was help from the West. In the end, the formula of the union was worked out, which included the Filioque, theses on purgatory, "unleavened bread" and papal claims. It was signed by all the Orthodox present at the council, with the exception of one, Archbishop Mark of Ephesus, who was later canonized by the Orthodox Church. The Florentine Union was based on a dual principle: agreement in doctrinal matters and respect for the legitimate traditions and rites of each church. Thus, in matters of doctrine, the Orthodox recognized papal claims (although the formula of the union in its verbal expression was somewhat vague and ambiguous), recognized the thesis of the double procession of the Holy Spirit (although they were not required to introduce the Filioque into the text of the Divine Liturgy), and recognized the Roman Catholic teaching on purgatory (one of the points of divergence between East and West, which was revealed only in the thirteenth century). But as for the "unleavened bread," there was no need for unanimity: the Greeks were allowed to eat sour dough, while the Latins continued to eat unleavened dough.

But although the Florentine Union was celebrated throughout Western Europe—bells rang in all the parish churches of England—it proved to be no more viable than the Union of Lyons that preceded it. John VIII and his successor Constantine XI (the last Byzantine emperor and eighteenth in a row from Constantine the Great) remained faithful to the union; but they were powerless to impose it on their subjects, and did not even dare to proclaim it publicly in Constantinople until 1452. The decisions of the council were recognized only by an insignificant part of the Byzantine clergy and people. As if echoing what the emperor's sister said after Lyon, Grand Duke Luca Notaras declared: "I prefer to see a Muslim turban in the center of the city than a Latin mitre."

John and Constantine hoped that the Union of Florence would provide them with military support from the West, but the real help turned out to be negligible. On April 7, 1453, the Turks began an assault on Constantinople by land and sea. Outnumbered by more than 20 times, the Byzantines heroically held the line for seven long weeks. But the situation was hopeless. Early in the morning of May 29, the last Christian service was held in the Cathedral of St. Sophia. It was a joint service of the Orthodox and the Roman Catholics: at this decisive hour, the supporters and opponents of the Florentine Union forgot their differences. The emperor left the cathedral after communion and died fighting on the walls of the city. On the same day, in the late afternoon, the city was taken by the Turks, and the most famous temple in Christendom became a mosque.

It was the end of the Byzantine Empire. But not the end of the Patriarchate of Constantinople, much less the end of Orthodoxy.

CONVERSION OF THE SLAVS

The grace-filled faith spread throughout the whole earth and finally reached the Russian people... The merciful God, who cares for all countries, no longer despises us. It was His desire to save us and bring us to reason.

Иларион, митрополит Руси (1051–1054?)

Кирилл и Мефодий

Середина IX в. была для Константинополя периодом интенсивной миссионерской деятельности. Избавившись наконец от долгой иконоборческой смуты, Византийская церковь обратила свою энергию на обращение язычников–славян, живших к северу и северо–востоку от границ империи — моравов, болгар, сербов и русичей. Первым Константинопольским патриархом, развернувшим широкомасштабную миссионерскую деятельность среди славян, был Фотий. Для этой цели он выбрал двух братьев, фессалоникийских греков Константина (826–869) и Мефодия (815? — 885). В Православной церкви Константина обычно называют Кириллом — по имени, которое тот принял в монашестве, в более ранние годы он был известен как «Константин–философ». Константин был самым способным из учеников Фотия, знатоком множества языков, в том числе арабского, еврейского и даже самаритянского диалекта. Но особо сведущими Константин и его брат были в славянском языке: еще в детстве они изучили диалект славян, живших в окрестностях Фессалоник, и могли свободно говорить на нем.

Первым миссионерским путешествием Кирилла и Мефодия стала в 860 г. краткая поездка к хазарам, жившим к северу от Кавказа. Она не имела долговременного успеха, и несколькими годами позже хазары приняли иудаизм. Реальная деятельность братьев началась в 863 г., когда они отправились в Моравию (территориально совпадавшую в общих чертах с позднейшей Чехословакией). Миссия братьев была направлена в Моравию в ответ на просьбу Моравского князя Ростислава прислать миссионеров, способных проповедовать народу на его собственном наречии и вести службу на славянском языке. Но славянская служба требовала славянской Библии и славянских богослужебных книг. Прежде чем отправиться в Моравию, братья принялись за гигантскую переводческую работу, а прежде им нужно было изобрести подходящую славянскую азбуку. При переводе братья использовали ту форму славянского языка, которая была известна им с детства: македонский диалект славян из окрестностей Фессалоник. Так диалект македонских славян стал церковнославянским языком, который до сего дня остается литургическим языком Русской церкви и некоторых других православных славянских церквей.