By the time of the Charlemagne, the West and East had drifted apart significantly. Due to political and religious differences, these two pillars of Christendom had become both geographically and theologically separated. While still in canonical communion, they hardly knew what the other did. By the time the year 1054 A.D. rolled around, the East and West differed on both theology and orthopraxy.
Papal Supremacy – a doctrine which some would call “necessary to salvation” and others “precursor to the antichrist” – reaches to the heart of the Church. Scholars differ as to when Papal Supremacy was first invented. Some claim it was initiated at the dawn of Christendom, and others insist it was an invention of tyrannical Popes. Regardless, the West insisted that Papal Supremacy is given in scripture, when Jesus builds His Church upon the Rock (i.e., Peter). According to both Eastern and Western theology, as Peter’s successor, the Pope would then hold the same authority Peter did. The question is thus: what authority did Peter receive? To the West, he received authority over the entire Church; to the East, he received primacy (a title simply of respect) but not supremacy.
The second dividing issue between East and West involved the Creed, the one thing which should have brought the two pillars together. Filioque – a phrase which some called “most holy dogma” and others “artifice of the devil” – has a long, often confusing, and somewhat bizarre history of theological mayhem. (Although linguistic differences in Latin and Greek can account for some of the controversy, it cannot account for every discrepancy.) The phrase means “and the Son” and is applied to the Nicene Creed so that it reads, “the Holy Spirit … who proceeds from the Father and the Son”. The Filioque was not originally included in the creed, but some western Churches added it in order to combat Arianism (the Arians claimed that since the Son was not mentioned alongside the Father, He must be a lesser being.) Eastern Churches, however, criticized the Filioque as being not only novel but theologically erroneous. Despite these allegations, the West continued their use of the Filioque, and eventually even the Pope of Rome accepted and required its use. The East presented their theological problems with the creed with three basic premises: Scripture, Patristics, and Philosophy. To them, the Filioque violated Christ’s very words in John 15:26 and introduced a concept previously unrecognized as part of biblical theology. The East argued that the Filioque violated the Church Fathers’ teachings regarding the Trinity, but also violated their emphatic words in the creed. To the East, the Filioque was philosophically absurd and introduced impenetrable logical errors (for instance, some eastern theologians claimed the Filioque made the Spirit lesser than the Father and Son since the Father and Son shared a quality [causation] that the Spirit did not.) Not only this, but the Filioque was added to the Creed without eastern consent, an Ecclesiastical and Political move which caused some unrest. The West, of course, replied to these accusations with many of the same arguments. They reasoned that since the Spirit is called “Spirit of the Son” throughout Scripture, it is reasonable to assume the Spirit also proceeds from Him. They cited various Church Fathers (especially Augustine) who had used language which implies procession from the Son, and they brought out their own philosophical arguments as well (for instance, Christ says “all that the Father has is mine” and that must include the quality of causation). Unfortunately, despite multiple Church councils, linguistic clarifications, and many attempts at unity, the issue was never resolved. Some say the teachings of Maximos the Confessor, Gregory Palamas, and various others have resolved the issue of Filioque, but it is yet to be realized.
In the year 1054 Patriarch Michael Cerularius and Cardinal Humbert mutually exchanged anathemas. Following this catastrophic event, more excommunications followed. Although some individual Churches stayed in communion for centuries, the Eastern (now Orthodox) and Western (now Roman Catholic) Churches were out of communion indefinitely. This event is known as The Great Schism.