section_path: Historic divisions in Christianity/Great Schism
section_name: Great Schism
paragraph_text: Great Schism
  
  Although the Christian world as a whole did not experience any major church divisions for centuries afterward, the Eastern, predominantly Greek-speaking and Western, predominantly Latin-speaking, cultural divisions drifted toward isolation, culminating in the mutual excommunication of Patriarch of Constantinople Michael I Cerularius and the legate of then-deceased Pope of Rome Leo IX in 1054, in what is known as the Great Schism. The canonical separation was sealed by the Latin sacking of Constantinople (1204) during the Fourth Crusade and through the poor reception of the Council of Florence (1449) among the Orthodox Eastern Churches.
  
  The political and theological reasons for the schism are complex. Aside from the natural rivalry between the Eastern Roman or Byzantine Empire and the Franco-Latin Holy Roman Empire, one major controversy was the inclusion and acceptance in the West in general—and in the diocese of Rome in particular—of the Filioque clause ("and the Son") into the Nicene-Constantinopolitan Creed, which the East viewed as a violation of ecclesiastical procedure at best, an abuse of papal authority as only an Ecumenical Council could amend what had been defined by a previous council, and a heresy at worst, inasfar as the Filioque implies that the essential divinity of the Holy Spirit is derived not from the Father alone as arche (singular head and source), but from the perichoretic union between the Father and the Son. That the hypostasis or persona of the Spirit either is or is produced by the mutual, pre-eternal love between God and His Word is an explanation which Eastern Christian detractors have alleged is rooted in the medieval Augustinian appropriation of Plotinian Neoplatonism. (See Augustine of Hippo, De Trinitate.)
  
  Both West and East agreed that the patriarch of Rome was owed a "primacy of honour" by the other patriarchs (those of Alexandria, Antioch, Constantinople and Jerusalem), but the West also contended that this primacy extended to jurisdiction, a position rejected by the Eastern patriarchs. Various attempts at dialogue between the two groups would occur, but it was only in the 1960s, under Pope Paul VI and Patriarch Athenagoras, that significant steps began to be made to mend the relationship between the two. In 1965, the excommunications were "committed to oblivion".
  
  The resulting division remains, however, providing the Catholic Church and the Eastern Orthodox Church, both of which are globally distributed bodies and no longer restricted geographically or culturally to the "West" or "East", respectively. (There exist both Eastern Rite Roman Catholicism and Western Rite Orthodoxy, for example.) There is an ongoing and fruitful Catholic-Orthodox dialogue.