'One of the most futile, yet perhaps inevitable, of the many divisions within Christianity has been the break between Roman Catholicism and Eastern Orthodoxy -- seen at its most tragic today in Bosnia. Political and cultural reasons, as much as theological ones, dictated that Western Christendom and its Eastern half should part ways. Pope John Paul II's encyclical letter, Ut Unum Sint ('that they may all be one') addresses this ancient quarrel.

'By the 5th century, the western half of the Roman Empire had collapsed as a political unit. But it was still spiritually led by the see of Rome, and its ecclesiastical language was Latin. In the East, the Empire lived on in Byzantium or 'Constantinople' and was governed in the Greek tongue. The two halves began to compete for souls. The Polish Pope is, for instance, a product of the Roman Catholic Church's missionary zeal in Eastern Europe; Russian Orthodoxy is a product of 10th-century evangelism by Constantinople. To this day, especially in Bosnia and Ukraine, the fault-lines between the two jurisdictions have been regarded as a matter of great importance, sometimes, regrettably, of life and death.

'To outsiders the theological difference between the two churches over the Filioque clause (Rome believes that in the Trinity the Holy Spirit proceeds from the Son as well as the Father, while Orthodoxy holds from the Father alone) seem like a hair-splitting. But theology to the layman often appears arcane. Layman and cleric alike are right to deplore the lack of charity displayed by the two churches, from 1054, when Pope Leo IX and the Patriarch of Constantinople, Michael Cerularius, hurled anathemas across the alter of Hagia Sophia itself, the churches even refused to recognize each other....

'The theologians will decide whether John Paul II's humble apologies for his Church's errors and his plea for 'legitimate diversity' are enough to calm Eastern Orthodoxy's fears over his claims to primacy and uthority. The intriguing possibility remains, however, that if the two churches surmount their divisions, the trickle of conservative Anglicans seeking communion with Rome, and Constantinople, will become a flood. If the Pope's encyclical were to be followed by full union, history might remember him less for his controversial forays into birth control and more as the man who achieved 'the impossible': unity between East and West' (The Times, London, May 31, 1995).