I. He congratulates them on their outspoken resistance to error.
Leo the bishop to the clergy, dignitaries, and people, residing at Constantinople.
Though we are greatly grieved at the things reported to have been done recently in the council of priests at Ephesus, because, as is consistently rumoured, and also demonstrated by results, neither due moderation nor the strictness of the Faith was there observed, yet we rejoice in your devoted piety and in the acclamations of the holy people, instances of which have been brought to our notice, we have approved of the right feeling of you all; because there lives and abides in good sons due affection for their excellent Father, and because you suffer the fullness of Catholic teaching to be in no part corrupted. For undoubtedly, as the Holy Spirit has unfolded to you, they are leagued with the Manichæans' error, who deny that the only-begotten Son of God took our nature's true Manhood, and maintain that all His bodily actions were the actions of a false apparition. And lest you should in anything give your assent to this blasphemy, we have now sent you, beloved, by my son Epiphanius and Dionysius, notary of the Roman Church, letters of exhortation wherein we have of our own accord rendered you the assistance which you sought, that you may not doubt of our bestowing all a father's care on you, and labouring in every way, by the help of God's mercy, to destroy all the stumbling-blocks which ignorant and foolish men have raised. And let no one venture to parade his priestly dignity who can be convicted of holding such detestably blasphemous opinions. For if ignorance seems hardly tolerable in laymen, how much less excusable or pardonable is it in those who govern; especially when they dare even to defend their mendacious and perverse views, and persuade the unsteadfast to agree with them either by intimidation or by cajoling.
Source: Letters (New Advent)