11 Hippocrates in his Aphorisms teaches that stout persons of a coarse habit of body, when once they have attained their full growth, unless the plethora be quickly relieved by blood-letting, develop tendencies to paralysis and the worst forms of disease: they must therefore be bled, that there may be room for fresh growth. For it is not the nature of our bodies to continue in one stay, but go on either to increase or decrease, and no animal can live which is incapable of growth.
Whence Galen, a very learned man and the commentator on Hippocrates, says in his exhortation to the practice of medicine that athletes whose whole life and art consists in stuffing cannot live long, nor be healthy: and that their souls enveloped with superfluous blood and fat, and as it were covered with mud, have no refined or heavenly thoughts, but are always intent upon gluttonous and voracious feasting. Diogenes maintains that tyrants do not bring about revolutions in cities, and foment wars civil or foreign for the sake of a simple diet of vegetables and fruits, but for costly meats and the delicacies of the table.
And, strange to say, Epicurus, the defender of pleasure, in all his books speaks of nothing but vegetables and fruits; and he says that we ought to live on cheap food because the preparation of sumptuous banquets of flesh involves great care and suffering, and greater pains attend the search for such delicacies than pleasures the consumption of them. Our bodies need only something to eat and drink. Where there is bread and water, and the like, nature is satisfied. Whatever more there may be does not go to meet the wants of life, but are ministers to vicious pleasure.
Eating and drinking does not quench the longing for luxuries, but appeases hunger and thirst. Persons who feed on flesh want also gratifications not found in flesh. But they who adopt a simple diet do not look for flesh. Further, we cannot devote ourselves to wisdom if our thoughts are running on a well-laden table, the supply of which requires an excess of work and anxiety. The wants of nature are soon satisfied: cold and hunger can be banished with simple food and clothing. Hence the Apostle says: “Having food and clothing let us be therewith content.”
Delicacies and the various dishes of the feast are the nurses of avarice. The soul greatly exults when you are content with little: you have the world beneath your feet, and can exchange all its power, its feasts, and its lusts, the objects for which men rake money together, for common food, and make up for them all with a sack-cloth shirt. Take away the luxurious feasting and the gratification of lust, and no one will want riches to be used either in the belly, or beneath it.
The invalid only regains his health by diminishing and carefully selecting his food, i.e., in medical phrase, by adopting a “slender diet.” The same food that recovers health, can preserve it, for no one can imagine vegetables to be the cause of disease. And if vegetables do not give the strength of Milo of Crotona— a strength supplied and nourished by meat— what need has a wise man and a Christian philosopher of such strength as is required by athletes and soldiers, and which, if he had it, would only stimulate to vice?
Let those persons deem meat accordant with health who wish to gratify their lust, and who, sunk in filthy pleasure, are always at heat. What a Christian wants is health, but not superfluous strength. And it ought not to disturb us if we find but few supporters; for the pure and temperate are as rare as good and faithful friends, and virtue is always scarce. Study the temperance of Fabricius, or the poverty of Curius, and in a great city you will find few worthy of your imitation. You need not fear that if you do not eat flesh, fowlers and hunters will have learned their craft in vain.
Source: Against Jovinianus (New Advent)