People who know they have weak stomachs always eat something before important meetings to settle their bile. Physical exhaustion makes bile especially irritated. This happens either because fatigue pulls vital heat toward the center of the body, harming the blood and slowing circulation by clogging veins, or because a worn-out, weakened body affects the mind. This explains why sick people and the elderly get angry more easily than others. You should avoid hunger and thirst for the same reason — they make minds agitated and irritable. There's an old saying: "a weary man is quarrelsome." So is a hungry man, or a thirsty man, or anyone suffering from any cause. Just as sores hurt at the slightest touch, and then hurt even at the fear of being touched, an unsound mind takes offense at the smallest things. Even a greeting, a letter, a speech, or a question can make some people angry.
For this reason those who cannot trust their digestion, when they are about to transact business of importance always allay their bile with food, for it is peculiarly irritated by fatigue, either because it draws the vital heat into the middle of the body, and injures the blood and stops its circulation by the clogging of the veins, or else because the worn-out and weakened body reacts upon the mind: this is certainly the reason why those who are broken by ill-health or age are more irascible than other men. Hunger also and thirst should be avoided for the same reason; they exasperate and irritate men’s minds: it is an old saying that “a weary man is quarrelsome “: and so also is a hungry or a thirsty man, or one who is suffering from any cause whatever: for just as sores pain one at the slightest touch, and afterwards even at the fear of being touched, so an unsound mind takes offence at the slightest things, so that even a greeting, a letter, a speech, or a question, provokes some men to anger.