Gregory to Marinianus, bishop of Ravenna. Many things, dearest brother, does infirmity compel us to do, for which, were we in health, we should rightly seem blameworthy. But since, placed in this frail body, we cannot subsist otherwise than by serving its weaknesses, we ought not to blush at what necessity imposes. And therefore, since physicians declare fasting to be altogether harmful to those who suffer from a flow of blood, we exhort your Fraternity with these words, that, recalling to mind those things you are wont to endure from illness, you should by no means lay upon yourself the labour of fasting. But if by God's mercy you know yourself to be so far improved, and your strength able to suffice, we permit you to fast once or twice a week.
But above all it befits you to take care that you should in no way suffer any aggravation, lest the sickness, which now is lighter and is thought as it were held in suspense, be afterward felt more grievously through exacerbation.