III. Those who recant their error must be treated with forbearance.
And yet because such men have harmed themselves most by their wrong-doing, and because the greater the wounds, the more careful must be the application of the remedy, I have never in any letter maintained that pardon must be withheld even from them if they came to their right mind. And although we unchangeably abhor their heresy, which is the greatest enemy of Christian religion, yet the men themselves, if they without any doubt amend their ways and clear themselves by full assurances of repentance, we do not judge to be outcasts from the unspeakable mercy of God: but rather we lament with those that lament, “we weep with those that weep,” and obey the requirements of justice in deposing without neglecting the remedies of loving-kindness: and this, as your piety knows, is not a mere word-promise, but is also borne out by our actions, inasmuch as nearly all who had been either misled or forced into assenting to the presiding bishops, by rescinding what they had decreed and by condemning what they had written, have obtained complete acquittal from guilt and the boon of Apostolic peace.
Source: Letters (New Advent)