The position taken by Constantine in regard to Rome was largely fostered by the powerful Roman ideology that had been transferred to Constantinople, the ‘New Rome.’ The politico-religious thought of the Emperors and the people was to be affected first; the canonico-theological thought of the Patriarchs and clergy was to be affected later.
The idea of Constantinople as the New Rome was not that of Constantine himself, but it devolved from his action, and the transference of all the taxis of ancient Rome to Byzantium. This theme has been treated in many publications. Along with the immense prestige of Rome, there was in Byzantium the consciousness of continuing the Roman Empire; this, too, has often been emphasized by the commentators; (Romaios = Byzantine). It was inevitable, especially in the actual and ideological framework of a Church of Empire, that the idea of Constantinople as New Rome should entail ecclesiological and canonical consequences, the very ones that are generally and quite simply classed under the heading “ambition of the Patriarchs of Constantinople.” We will return to this later in our comments. If there had been a transfer of Empire, it was reasoned, there had consequently also been a transfer of ecclesiological primacy.
Needless to say, Rome regarded with coolness, or rather affected to ignore, the idea of Constantinople as a New Rome. Likewise, from the Eighth Century onward, in order to hold back the spread of this idea, Rome made use of the famous Donatio Constantini, one of the most harmful pieces of forgery known to history (and not merely to the history of Rome). It was a weapon, moreover, which betrayed the very cause of Rome, since by argument ad hominem, the Donatio in seeking to check the Emperor, presents the dignity of Peter and his successors and the privileges attached to that position as emanating from the political power of an Emperor and not from the Apostolic institution. Byzantium retained all the more the logic of her positions by retorting with her own argument from the Tenth Century onward, and by relying upon the Donatio to affirm that Constantine had transferred all the taxis to Constantinople, including that of making decisions in ecclesiastical affairs.
The transfer of the ideology of Rome to Byzantium constituted for the East and for a Church of Empire a principle all the more powerful in that it was reinforced by what we may call the “unitarian” ideal or idea. According to this idea, terrestrial government and the terrestrial order of things imitate celestial government and the celestial order of things; therefore, there can be on earth but one order, one truth, one justice, one power, of which the custodian is the image and representative of God; to one God in Heaven, one sole monarch corresponds on earth, by right at least. The origins of these ideas have been traced from Aristotle (whether in the original text which ends the Metaphysics or in the “platonizing” text found in De Mundo), passing through Philo Judaeus down to Eusebius of Caesarea, the thinker who has expressed the idea most theologically by applying it precisely to the Christian Empire of Constantine. Despite his weakness in theology, the influence of Eusebius cannot be exaggerated. Christian society is in the image of the Heavenly Kingdom, and of the politeia of Heaven. It embraces in a unique order, under the authority of the Emperor, all the aspects of life. By right, it covers the whole world and thus the Byzantine Basileis affirmed their right to the obedience of the barbarian and pagan kings themselves, beyond the frontiers of the Empire.
This “unitarian” ideology reigned in Byzantium. Indeed, a thesis could be developed on the idea of sovereignty which resulted from it. It also prevailed in the West, at least from the Eighth Century onward, first of all to the profit of the Emperor (from Charlemagne to Gregory VII), then rather to the profit of the Pope – not without claims asserted on the part of the temporal monarchs. A great many things in the history of Christianity may be explained if one keeps this “unitarian idea” in mind. The instances are almost innumerable. Here we need interest ourselves in these themes only from the viewpoint of the estrangement, which we will try to understand in its origin and development. It might not go beyond the facts to state that in Byzantium there prevailed the idea of a transfer of universal sovereignty of God to a “unitarian” order; but this transfer was more imperial than ecclesiastical. The idea that the unity of the Kingdom should be reflected in the Church, in its very structure, was not applied as far as the visible and social features of the Church were concerned, but it remained entirely mystical in the order of prayer and sacraments.
Besides, considering the total Christian world, there was not merely one “unitarian” order but two: therefore, one too many. For opposing the Byzantine Basileus there arose another “Emperor.” And, opposing the Emperor and finally confronting any monarch claiming to be the sovereign head of the Christian world, the pope raised a higher claim, progressively expressed in occasional assertions of powe, first in Canon law – in the Eighth to Eleventh Century – then in theology – in the Thirteenth Century – and finally in dogma, by the Vatican Council.
But many episodes in the history of Western Christianity have completely betrayed the Byzantine ideal just defined. We generally blame both sides in this betrayal; it has also been said that the Basileis lacked a feeling of solidarity with the West which they abandoned to its destiny save for a few attempts such as the grandiose one of Justinian. They also lacked an historical sense, if we may use a modern expression; they did not accept the West for what it was, and were too prone to assume an attitude of contempt. But it is evident that the West was the more at fault regarding the Roman idea transferred to Constantinople and the “unitarian” ideal embodied in the Empire. To begin with, the West fell under the domination of the barbarians and Rome itself was captured. Thus, barbarian Rome could be considered as no longer a part of the Empire, and as no longer expressing the Roman idea, which continued only in Constantinople. Better still, the West and Rome itself “went over to the barbarians” in the sense that Ozanam expressed in his famous declaration. The Romans allied themselves with the enemies of the Empire as, for example, happened in the Eleventh Century with the Normans. In short, while rendering momentary homage to the Byzantine idea and to the legitimacy of the unique claims of Constantinople, the West completed its betrayal by creating an Emperor supposedly Roman, but in reality Germanic and barbarian: Pope John XIII was to go so far as to write in 967, that there was “an Emperor of the Greeks” and “an Emperor of the Romans”!
Here the estrangement is between two worlds simultaneously political and cultural: the Byzantine world which affirms that it is the legitimate continuation of Rome, and the Latinized barbarian world, spiritually dominated by Apostolic and Papal Rome. The two worlds do not accept each other. Rome does not accept Constantinople, Constantinople does not accept the West as it is, and rather feels that this West has betrayed “the Roman idea of unity,” at least as considered in Byzantium, which is to say, Roman, in the sense of Imperial.