Didascalicon, Book II: the sciences, their parts and their discipline
Chapter XXVII. On medicine
Medicine is divided into two parts, occasions and operations. The occasions are six: air, motion and rest, emptying and filling, food and drink, sleep and waking, and the accidents of the soul. They are called occasions because they make and preserve health if they are tempered, and sickness if untempered. The accidents of the soul are called an occasion of health or sickness because they sometimes move the heat violently, as anger, or gently, as delights, or draw it in and hide it; and this either violently, as terror and fear, or gently, as anguish. And there are those which move the natural power within and without, as sadness. Every operation of medicine is done either within or without. Within, as those things that are introduced by mouth, nostrils, ears or anus, as potions, emetics, powders, clysters, etc., which are taken by drinking, chewing, or drawing in.
Without, as fomentations, poultices, plasters.
Surgery, which is twofold: in flesh, as to cut, to sew, to burn; in bone, as to knit and to restore the joints. Let it not trouble anyone that I number food and drink among the things attributed to medicine, which I attributed above to hunting, since this was done according to different respects. Wine too, in the grape, belongs to agriculture; in the store, to the cellarer; in the tasting, to the physician. Likewise the preparation of foods belongs to the butcher and the kitchen; the virtue of flavor to medicine.