In an attempt to be ‘irenic’, many Roman Catholics maintain that the Orthodox Church is not ‘in heresy’ but only ‘in schism’. More properly, this could be expressed as ‘the particular Churches of the Orthodox which are not in communion with the Church of Rome are schismatic and not fully catholic (yet not heretical)’. Roman Catholic books tend to refer to the Orthodox as ‘dissidents’ or ‘schismatics’ but more rarely as ‘heretics’. Unfortunately, this generous view is rather indefensible. Since Vatican I (1870), the Roman Catholic Church holds as a divinely revealed dogma that the Bishop of Rome is the sole successor of St. Peter with episcopal authority over the universal Church. Furthermore, the Council pronounced the anathema on those who reject this view, with a clear reference to the Orthodox interpretation:
“So, then, if anyone says that the Roman Pontiff has merely an office of supervision and guidance, and not the full and supreme power of jurisdiction over the whole Church, and this not only matters of faith and morals, but also in those which concern the discipline and government of the Church dispersed throughout the whole world; or that he only has the principal part, but not the absolute fullness, of this supreme power; or that this power of his is not ordinary and immediate both over all and each of the Churches and over all and each of the pastors and faithful: let him be anathema.”
“So then, should anyone, which God forbid, have the temerity to reject this definition of ours [regarding papal infallibility]: let him be anathema.”
It is therefore preferable and more honest to present things as they really are: the Roman Catholic Church teaches that the Orthodox are in a state of schism and heresy, under papal anathema. As the late Fr. John Hardon, S.J., explained quite frankly:
“Technically a schismatic differs from a heretic as one who sins against obedience or charity differs from a person who denies the faith. In the strict sense, a schismatic still admits the whole body of revelation but refuses to acknowledge the de facto authority of the Roman Pontiff or to share with the rest of the faithful in their practice of the Catholic religion. Since the Vatican definitions on papal authority, however, it is scarcely possible for a person to be only schismatic without also being a heretic. And even before the Vatican Council, it was common knowledge that those who originally broke with the Church’s unity for disciplinary reasons, before long ended by questioning certain articles of faith. An outstanding example is the so-called Eastern Orthodox Church…”
Conversely, there is no doubt that the Orthodox share the reciprocal view, as made clear by the following excerpt from the Encyclical of Eastern Patriarch (1848):
“Of these heresies was formerly Arianism, and at present the Papacy.”
Since Vatican I, the tone has changed and the mutual excommunications of 1054 have been lifted, but the dogmatic framework is still the same. In fact, it is the opinion of many observers, within both Catholicism and Orthodoxy, that the divide may be widening, not so much theologically as culturally and ‘ontologically’. In 1997, Patriarch Bartholomew of Constantinople made the following statement:
“We confirm not with unexpected astonishment, but neither with indifference, that indeed the divergence between us continually increases and to point to which are courses are taking us, foreseeably, is indeed different… The manner in which we exist has become ontologically different.”
If our goal is to work towards reconciliation, it is essential to be honest about what has been said in the past and what we believe today. Only then can both sides start anew with a genuine dialogue of ‘truth in love’. (His Broken Body: Understanding and Healing the Schism Between the Roman Catholic and Eastern Orthodox Churches, pp. 123-124 [kindle version])