To Marinianus, Bishop of Ravenna.
Gregory to Marinianus, etc.
Great infirmity constrains us, dearest brother, from which if we were free, we should seem justly blamable. But since, while we are in this fragile body, we cannot subsist but by subservience to its weaknesses, we ought not to blush for what necessity imposes on us. And so, since physicians all say that to those who suffer from eruption of blood fasts are injurious, we exhort your Fraternity by this present address that, recalling to mind what you have been accustomed to endure from sickness, you by no means impose on yourself the labour of fasting. If, however, by the mercy of God, you know yourself to be so far improved in health as to have sufficient strength, we permit you to fast once or twice in the week. But of this it befits you before all things to take care, that you in no wise subject yourself to any feeling of irritation, lest the sickness, which is believed to be now lighter and as it were suspended, should be experienced afterwards more heavily through exasperation.
Source: Register of Letters (New Advent)