E. Eastern Christianity
One of the most influential acts of Constantine the Great was his decision in 330 to move the capital of the empire from Rome to “New Rome,” the city of Byzantium at the eastern end of the Mediterranean Sea. The new capital, Constantinople (now Istanbul), also became the intellectual and religious focus of Eastern Christianity. While Western Christianity became increasingly centralized, a pyramid the apex of which was the pope of Rome (see Papacy), the principal centers of the East—Constantinople, Jerusalem, Antioch, and Alexandria—developed autonomously. The emperor at Constantinople held a special place in the life of the church. It was he, for example, who convoked and presided over the general councils of the church, which were the supreme organ of ecclesiastical legislation in both faith and morals. This special relation between church and state, frequently (but with some oversimplification) called Caesaropapism, fostered a Christian culture in which (as the great Church of the Holy Wisdom at Constantinople, dedicated by Emperor Justinian in 538, attests) the noblest achievements of the entire society blended the elements of Christianity and of classical antiquity in a new synthesis.
At its worst, this culture could mean the subordination of the church to the tyranny of the state. The crisis of the 8th century over the legitimacy of the use of images in Christian churches was also a collision of the church and the imperial power. Emperor Leo III prohibited images, thus precipitating a struggle in which Eastern monks became the principal defenders of the icons. Eventually the icons were restored, and with them a measure of independence for the church (see Iconoclasm). During the 7th and 8th centuries three of the four Eastern centers were captured by the dynamic new faith of Islam, with only Constantinople remaining unconquered. It, too, was often besieged and finally fell to the Turks in 1453. The confrontation with the Muslims was not purely military, however. Eastern Christians and the followers of the Prophet Muhammad exerted influence on one another in intellectual, philosophical, scientific, and even theological matters.
The conflict over the images was so intense because it threatened the Eastern church at its most vital point—its liturgy. Eastern Christianity was, and still is, a way of worship and on that basis a way of life and a way of belief. The Greek word orthodoxy, together with its Slavic equivalent pravoslavie, refers to the correct form for giving praise to God, which is finally inseparable from the right way of confessing true doctrine about God and of living in accordance with the will of God. This emphasis gave to Eastern liturgy and theology a quality that Western observers, even in the Middle Ages, would characterize as mystical, a quality enhanced by the strongly Neoplatonic strain in Byzantine philosophy (see Neoplatonism). Eastern monasticism, although often hostile to these philosophical currents of thought, nonetheless practiced its devotional life under the influence of writings of church fathers and theologians, such as St. Basil of Caesarea, who had absorbed a Christian Hellenism in which many of these emphases were at work.
All these distinctive features of the Christian East—the lack of a centralized authority, the close tie to the empire, the mystical and liturgical tradition, the continuity with Greek language and culture, and the isolation as a consequence of Muslim expansion—contributed also to its increasing alienation from the West, which finally produced the East-West schism. Historians have often dated the schism from 1054, when Rome and Constantinople exchanged excommunications, but much can be said for fixing the date at 1204. In that year, the Western Christian armies on their way to wrest the Holy Land from the hand of the Turks (see Crusades) attacked and ravaged the Christian city of Constantinople. Whatever the date, the separation of East and West has continued into modern times, despite repeated attempts at reconciliation.
Among the points of controversy between Constantinople and Rome was the evangelization of the Slavs, beginning in the 9th century. Although several Slavic tribes—Poles, Moravs, Czechs, Slovaks, Croats, and Slovenes—did end up in the orbit of the Western church, the vast majority of Slavic peoples became Christians in the Eastern (Byzantine) church. From its early foundations in Kyiv, Ukraine, this Slavic Orthodoxy permeated Russia, where the features of Eastern Christianity outlined above took firm hold. The autocratic authority of the Muscovite tsar derived some of its sanctions from Byzantine Caesaropapism, and Russian monasticism took over the ascetic and devotional emphases cultivated by the Greek monasteries of Mount Athos. The stress on cultural and ethnic autonomy meant that from its beginnings Slavic Christianity had its own liturgical language (still known as Old Church Slavic, or Slavonic), while it adapted to its uses the architectural and artistic styles imported from the centers of Orthodoxy in Greek-speaking territory. Also in the Eastern church were some of the Balkan Slavs—Serbs, Montenegrins, Bosnians, and Slavic Macedonians; the Bulgars, a Turkic people; Albanians, descendants of the ancient Illyrians; and Romanians, a Romance people. During the centuries-long rule of the Ottoman Turks in the Balkans some of the local Christian populations were forced to embrace Islam, as, for example, some of the Bosnians, some of the Bulgarians, and some of the Albanians.
F. Western Christianity
Although Eastern Christianity was in many ways the direct heir of the early church, some of the most dynamic development took place in the western part of the Roman Empire. Of the many reasons for this development, two closely related forces deserve particular mention: the growth of the papacy and the migration of the Germanic peoples. When the capital of the empire moved to Constantinople, the most powerful force remaining in Rome was its bishop. The old city, which could trace its Christian faith to the apostles Peter and Paul and which repeatedly acted as arbiter of orthodoxy when other centers, including Constantinople, fell into heresy or schism, was the capital of the Western church. It held this position when the succeeding waves of tribes, in what used to be called the “barbarian invasions,” swept into Europe. Conversion of the invaders to Catholic Christianity meant at the same time their incorporation into the institution of which the bishop of Rome was the head, as the conversion of the king of the Franks, Clovis I, illustrates. As the political power of Constantinople over its western provinces declined, separate Germanic kingdoms were created, and finally, in 800, an independent Western “Roman empire” was born when Charlemagne was crowned emperor by Pope Leo III. See Holy Roman Empire.
Medieval Christianity in the West, unlike its Eastern counterpart, was therefore a single entity, or at any rate strove to be one. When a tribe became Christian in the West, it learned Latin and often (as in the case of France and Spain) lost its own language in the process. The language of ancient Rome thus became the liturgical, literary, and scholarly speech of western Europe. Archbishops and abbots, although wielding great power in their own regions, were subordinate to the pope, despite his frequent inability to enforce his claims. Theological controversies occurred during the early centuries of the Middle Ages in the West, but they never assumed the proportions that they did in the East. Nor did Western theology, at least until after the year 1000, acquire the measure of philosophical sophistication evident in the East. The long shadow of St. Augustine continued to dominate Latin theology, and there was little independent access to the speculations of the ancients.
The image of cooperation between church and state, symbolized by the pope’s coronation of Charlemagne, must not be taken to mean that no conflict existed between the two in the Middle Ages. On the contrary, they clashed repeatedly over the delineation of their respective spheres of authority. The most persistent source of such clashes was the right of the sovereign to appoint bishops in his realm (lay investiture), which brought Pope Gregory VII and Holy Roman Emperor Henry IV to a deadlock in 1075. The pope excommunicated the emperor, and the emperor refused to acknowledge Gregory as pope. They were temporarily reconciled when Henry subjected himself in penance to the pope at Canossa in 1077, but the tension continued. A similar issue was at stake in the excommunication of King John of England by Pope Innocent III in 1209, which ended with the king’s submission four years later. The basis of these disputes was the complex involvement of the church in feudal society. Bishops and abbots administered great amounts of land and other wealth and were thus a major economic and political force, over which the king had to exercise some control if he was to assert his authority over his secular nobility. On the other hand, the papacy could not afford to let a national church become the puppet of a political regime. See Investiture Controversy.
Church and state did cooperate by closing ranks against a common foe in the Crusades. The Muslim conquest of Jerusalem meant that the holy places associated with the life of Jesus were under the control of a non-Christian power; and even though the reports of interference with Christian pilgrims were often highly exaggerated, the conviction grew that it was the will of God for Christian armies to liberate the Holy Land. Beginning with the First Crusade in 1095, the campaigns of liberation did manage to establish a Latin kingdom and patriarchate in Jerusalem, but Jerusalem returned to Muslim rule a century later and within 200 years the last Christian outpost had fallen. In this sense the Crusades were a failure, or even (in the case of the Fourth Crusade of 1202-04, mentioned above) a disaster. They did not permanently restore Christian rule to the Holy Land, and they did not unify the West either ecclesiastically or politically.
A more impressive achievement of the medieval church during the period of the Crusades was the development of Scholastic philosophy and theology. Building as always on the foundations of the thought of St. Augustine, Latin theologians turned their attention to the relation between the knowledge of God attainable by unaided human reason and the knowledge communicated by revelation. Saint Anselm took as his motto “I believe in order that I might understand” and constructed a proof for the existence of God based on the structure of human thought itself (the ontological argument). About the same time, Peter Abelard was examining the contradictions between various strains in the doctrinal tradition of the church, with a view toward developing methods of harmonization. These two tasks dominated the thinking of the 12th and 13th centuries, until the recovery of the lost works of Aristotle made available a set of definitions and distinctions that could be applied to both. The philosophical theology of Saint Thomas Aquinassought to do justice to the natural knowledge of God while at the same time exalting the revealed knowledge in the gospel, and it wove the disparate parts of the tradition into a unified whole. Together with such contemporaries as St. Bonaventure, Aquinas represents the intellectual ideal of medieval Christianity. See also Scholasticism.
Even by the time Aquinas died, however, storms were beginning to gather over the Western church. In 1309 the papacy fled from Rome to Avignon, where it remained until 1377 in the so-called Babylonian Captivity of the church. This was followed by the Great Schism (see Schism, Great), during which there were two (and sometimes even three) claimants to the papal throne. That was not resolved until 1417, but the reunited papacy could not regain control or even respect.