The words matter, so use them precisely. In Catholic teaching, heresy is “the obstinate post-baptismal denial of some truth which must be believed with divine and catholic faith”; apostasy is the total repudiation of the faith; and schism is “the refusal of submission to the Roman Pontiff or of communion with the members of the Church subject to him.” By those definitions the East–West breach is a schism — a rupture of communion — not heresy and not apostasy. (That schism is here defined as a refusal of submission to the Pope is itself part of the quarrel: the Orthodox do not concede that such submission was ever owed.) The Orthodox have not abandoned the faith, and the Catholic Church has not, in her current teaching, declared them heretics.

The proof is in how Rome speaks of them. She does not call the Orthodox a sect that forfeited the faith; she calls them “true particular Churches,” precisely because they keep apostolic succession and a valid Eucharist. The principal doctrinal question historically in dispute is the Filioque — and even there the modern Church frames the matter as a difference to be reconciled, not a heresy charge fired across the Bosphorus. The breach is about communion and the primacy, not about a denied article of the Creed.

And the modern Church has deliberately set down the old polemical clubs — which were swung from both sides. Vatican II prefers “separated brethren” to “schismatics,” and it draws the line charity requires: those born today into the separation “cannot be accused of the sin involved in the separation.” The Council embraces them “as brothers, with respect and affection.” Whatever happened in the eleventh century, the Orthodox Christian alive now inherited his situation; he did not commit it.

Honesty, then, three ways. “Schism” is no soft word — it is a real and grave wound to the unity Christ prayed for, listed in canon law beside heresy and apostasy; calling it schism-not-heresy clarifies the category, it does not minimize the loss. The charge also cuts both ways: the Orthodox return it with equal sincerity, holding that it was Rome that innovated and broke communion — a fair page must register that the rupture is mutual. And no individual today bears personal guilt for it. The truest name for the Orthodox is not “heretic,” and barely even “schismatic” in the accusing sense — it is separated brethren, with whom Rome longs to be one again.