The charge deserves its full force. The definition is dated 18 July 1870; for eighteen centuries the Church defined no such thing; the East never accepted it; and the clause that papal definitions are irreformable “of themselves, and not from the consent of the Church” (ex sese, non autem ex consensu Ecclesiae) is arguably the most extra-patristic sentence in the whole text. Above all there is Pope Honorius, whom the Third Council of Constantinople (681) — an ecumenical council Rome accepts — anathematized by name for the Monothelite error, a condemnation his own successor, Pope Leo II, confirmed. If a council can anathematize a reigning pope for heresy, how can the papacy be infallible?

The Catholic answer begins with what the dogma actually says. Infallibility is narrowly scoped: it covers only the pope teaching ex cathedra — as universal pastor, defining a doctrine of faith or morals to be held by the whole Church. It is not impeccability (popes sin), not inspiration (no new revelation), not a guarantee on private opinions, governance, or off-hand remarks. Vatican I defined a charism; it did not invent one — any more than Nicaea invented the Trinity by defining it under Arian pressure. “Consubstantial” is not in Scripture either, and no one calls the Trinity a fourth-century novelty.

And the charism was visibly at work before it was named. At Chalcedon the Fathers received Leo’s doctrinal Tome with the cry “Peter has spoken through Leo” — though, as the Orthodox rightly note, they received it because they had first judged it to agree with the faith; the Formula of Hormisdas had the East confess the Apostolic See’s unfailing faith. The line runs from “Rome’s see has kept the faith, as the council acclaims” to the 1870 precision — real development, by Newman’s logic, not a bolt from the blue.

Now Honorius, met head-on, because dodging him is dishonest. Three things are true at once. He was condemned — no Catholic may pretend otherwise. But he met not a single condition of an infallible act: he issued no ex cathedra definition; he wrote a private letter to one patriarch, failing to crush an error rather than solemnly defining one for the Church. And his own successor read his fault exactly so — Leo II confirmed the anathema because Honorius “did not… extinguish the flame of heretical teaching in its first beginning, but fostered it by his negligence.” Now candor requires admitting that the council’s own acts spoke harder — they named Honorius a heretic — and that to read his fault as negligence rather than heresy is Leo II’s confirmation, and the Catholic case, not a neutral record. But even on the council’s harsher reading the decisive point holds: what was condemned was a private letter, not an ex cathedra definition. Vatican I never claimed a pope cannot be silent, careless, or even gravely wrong in a private letter — only that when he defines ex cathedra, he is preserved. Honorius is the textbook case of a pope not exercising the charism: the council that condemned him and the council that defined infallibility point at two different acts. And there is a deeper point the Catholic must weigh, not wave away: the episode shows the early Church’s instinct was conciliar judgment, ready to weigh even a pope — the very conciliarity the East holds dear, and the ex sese clause is where Rome and the East genuinely part company.