II. The penitents among the backsliding bishops are to be received back into full communion upon some plan to be settled by Anatolius and Leo's delegates.
But concerning the brethren whom we learn from your letters, and from our delegates' account, to be desirous of communion with us, on the ground of their sorrow that they did not remain constant against violence and intimidation, but gave their assent to another's crime when terror had so bewildered them, that with hasty acquiescence they ministered to the condemnation of the Catholic and guiltless bishop (Flavian), and to the acceptance of the detestable heresy (of Eutyches), we approve of that which was determined upon in the presence and with the co-operation of our delegates, viz., that they should be content meanwhile with the communion of their own churches, but we wish our delegates whom we have sent to consult with you, and come to some arrangement whereby those who condemn their ill-doings with full assurances of penitence, and choose rather to accuse than to defend themselves, may be gladdened by being at peace and in communion with us; on condition that what has been received against the Catholic Faith is first condemned with complete anathema.
For otherwise in the Church of God, which is Christ's Body, there are neither valid priesthoods nor true sacrifices, unless in the reality of our nature the true High Priest makes atonement for us, and the true Blood of the spotless Lamb makes us clean. For although He be set on the Father's right hand, yet in the same flesh which He took from the Virgin, he carries on the mystery of propitiation, as says the Apostle, “Christ Jesus Who died, yea, Who also rose, Who is on the right hand of God, Who also makes intercession for us.”
For our kindness cannot be blamed in any case where we receive those who give assurance of penitence, and at whose deception we were grieved. The boon of communion with us, therefore, must neither harshly be withheld nor rashly granted, because as it is fully consistent with our religion to treat the oppressed with a Christlike charity, so it is fair to lay the full blame upon the authors of the disturbance.
Source: Letters (New Advent)