The See of Peter

The Early Church and Peter's Primacy

Letter LX, from Pope Leo to Empress Pulcheria

Synopsis: Leo writes to Pulcheria Augusta to praise her letter’s demonstration of Catholic devotion and hatred of heresy, and to explain why the Eutychian error — which denies that the eternal Son of God assumed the true flesh of our nature from the Virgin — is impious and contrary to the Gospel, being an error so destructive that it attacks the very foundations of the Christian religion; and to press again for a general council.

Leo, bishop, to Pulcheria Augusta.

Praise of Pulcheria’s Faith; The Eutychian Error Strikes at the Foundations of the Christian Religion; A General Council Is Sought

Your piety’s letters have caused me very great joy and exultation in the Lord — through which it is clearly shown how much you love the Catholic faith and how much you detest the heretical error. For heresy is altogether too impious and contrary to the truth of the Gospel — which does not seek to wound some part, but strives to overthrow the very foundations of the Christian religion itself — denying that the eternal Son of the eternal Father assumed our true flesh from the womb of the blessed Virgin Mother, and striking with condemnation those who have sought a remedy from their error.

What the piety of the evangelical and apostolic faith defends has already been set out in my letters, which I believe Your Clemency received some time ago through Epiphanius the tribune, dispatched for this purpose. And through these Our writings We have explained all that should be held concerning the mystery of the divine Incarnation, declaring the unity of the two natures in the one person of Christ.

We beg, therefore, that a general council be convened against those who are disturbing the peace of the Church — so that the faith defined by the holy Fathers at Nicaea, which We hold pure, and which We assert most firmly, may be confirmed throughout all the churches, and that Catholic peace may be restored in Your Clemency’s times.

Given on the sixteenth day before the Kalends of April, in the seventh consulship of Valentinian Augustus and in the consulship of Avienus, most illustrious men.

Source/Reference

PL 54:873

Notes / Historical Commentary

Letter LX is addressed to Pulcheria in April 450 — the latest in Leo’s sustained campaign to bring Eastern imperial authority behind his demand for a new council. The letter covers familiar ground (the Eutychian error, the faith of Nicaea, the request for a council) and its main interest lies in the context rather than the content: Leo is still pressing in April 450 what he began pressing in August 449, and the Eastern emperor has not moved. Pulcheria remains Leo’s most reliable contact in Constantinople — a woman of genuine theological conviction who had been the driving force behind Nicene orthodoxy at the 431 Council of Ephesus and whose influence over her brother Theodosius, while real, was limited on this question.

The letter’s dateline carries the historical weight. April 16, 450. Theodosius II would die three months later in a riding accident. His successor Marcian — who married Pulcheria and shared her orthodox convictions — would authorize Chalcedon before the year was out. Leo’s patience across nine months of pressing without result was about to be vindicated, not by Theodosius’s consent, but by Providence operating through Theodosius’s death. The reader of the full corpus will find it instructive that the Council of Chalcedon, which defined the faith and confirmed Leo’s Tome as its doctrinal standard, came about not through the conversion of an obstinate Eastern emperor but through his replacement by one who agreed with Rome from the outset.