One of the Greek words for “gluttony” is “γαστριμαργία”, a compound derived from “γαστρ- – stomach” and “μάργος – mad, furious”: hence, “madness of the belly.” St John Cassian, whose feast we noted yesterday, was fluent in both Greek and Latin, but when he wrote his Institutes, he preferred to transcribe the term into Latin as “gastrimargia”, rather than use the normal Latin word “gula.” This must be because “gula”, which at first meant simply “throat”, can also mean the more neutral “taste” or “appetite”, and Cassian felt it was not sufficiently pejorative to describe a vice, whereas the Greek term, which contains a root meaning “madness”, cannot be taken in a positive sense.
Here then is a piece of his wisdom about the discipline of fasting, something appropriate to the current Lenten season, taken from the fifth book of the Institutes, “On the spirit of gluttony”, chapter 5.
“̆… super jejuniorum modo haud potest facile uniformis regula custodiri, quia nec robur unum cunctis corporibus inest, nec, sicut caeterae virtutes, animi solius rigore parantur. Et idcirco, quia non in sola fortitudine mentis consistunt, cum corporis enim possibilitate participant, talem super his definitionem traditam nobis accepimus, diversum esse refectionis quidem tempus ac modum et qualitatem, pro impari scilicet corporum statu, vel aetate ac sexu: unam tamen esse omnibus pro mentis continentia et animi virtute castigationis regulam. Neque enim cunctis possibile est hebdomadibus protelare jejunia, sed ne triduana quidem, vel biduana, inedia refectionem cibi differre. A multis quippe aegritudine et maxime senio jam defessis, ne usque ad occasum quidem solis jejunium sine afflictione toleratur. Non omnibus infusorum leguminum esus convenit enervatus, nec cunctis purorum olerum habilis est parcimonia, nec universis sicci panis refectio castigata conceditur. Alius quantitate librarum duarum saturitatem non sentit; alius librae unius, sive unciarum sex edulio praegravatur; attamen unus in omnibus his continentiae finis est, ne quis juxta mensuram capacitatis suae saturitatis oneretur ingluvie. Non enim qualitas sola, sed etiam quantitas escarum, aciem cordis obtundit, ac mente cum carne pariter impinguata, noxium vitiorum fomitem igneumque succendit.
(A Greek icon of St Onuphrius, one of the Egyptian desert Fathers; his life was written by St Paphnutius, whom John Cassian knew personally. He is traditionally shown in this manner, with a body made very thin indeed by long periods of fasting. Public domain image from Wikimedia Commons.)

… concerning the manner of fasting, a uniform rule cannot easily be observed, because not every body has the same strength; nor is it like the rest of the virtues, acquired by steadfastness of mind alone. And therefore, because it does not consist only in mental strength, since it has to do with the possibilities of the body, we have received this explanation concerning it which has been handed down to us, that there is a difference of time, manner, and quality of refreshment in proportion to the difference of condition of various bodies, both in age and sex: but there is one rule of restraint for all as regards continence of mind, and the virtue of the spirit. For it is not possible for all to prolong their fast for weeks, or to postpone some refreshment during an abstinence of two or three days. By many people also who are worn out with sickness and especially with old age, a fast even up to sunset cannot be endured without suffering. The weakly food of moistened beans does not agree with everybody: nor does a sparse diet of fresh vegetables suit all, nor is a scanty meal of dry bread permitted to all alike. One man does not feel satisfied with two pounds, for another a meal of one pound, or six ounces, is too much; but among them all, there is one aim and object of continence, that no one may be overburdened according to the measure of his appetite by gluttony. For not only the quality, but also the quantity of food dulls the keenness of the heart, and, when the mind is surfeited along with the flesh, kindles the harmful and fiery incentive to the vices.”