II. He asks Julian to act for him as Anatolius is deficient in vigour.
See then, beloved brother, that you bestow the necessary thought on the cares of the Apostolic See, which by her rights as your mother commends to you, who were nourished at her breast, the defence of the Catholic Truth against Nestorians and Eutychians, in order that, supported by the Divine help, you may not cease to watch the interests of the city of Constantinople, lest at any time the storms of error arise within her. And because the faith of our glorious Princes is so great that you may confidently suggest what is necessary to them, use their piety for the benefit of the universal Church.
But if ever you consult me, beloved, on things which you think doubtful, my reply shall not fail to supply instruction, so that, apart from cases which ought to be decided by the inquiries of the bishops of each particular church, you may act as my legate and undertake the special charge of preventing the Nestorian or Eutychian heresy reviving in any quarter; because the bishop of Constantinople does not possess Catholic vigour, and is not very jealous either for the mystery of man's salvation or for his own reputation: whereas if he had any spiritual activity, he ought to have considered by whom he was ordained, and whom he succeeded in such a way as to follow the blessed Flavian rather than the instruments of his promotion.
And, therefore, when our most religious Princes deign in accordance with my entreaties to reprimand our brother Anatolius on those matters, which deservedly come under blame, join your diligence to theirs, beloved, that all causes of offenses may be removed by the application of the fullest correction and he cease from injuring our son Aetius. For with a Catholic-minded bishop even though there was something which seemed calculated to annoy in his archdeacon, it ought to have been passed over from regard for the Faith, rather than that the most worthless heretic should take the place of a Catholic.
And so when I have learned the rest of the story, I shall then more clearly gather what ought to be done. For, meanwhile, I have thought better to restrain my vexation and to exercise patience that there might be room for forgiveness.
Source: Letters (New Advent)