In acute diseases the physician must conduct his inquiries in the following way. First he must examine the face of the patient, and see whether it is like the faces of healthy people, and especially whether it is like its usual self. Such likeness will be the best sign, and the greatest unlikeness will be the most dangerous sign. The latter will be as follows. Nose sharp, eyes hollow, temples sunken, ears cold and contracted with their lobes turned outwards, the skin about the face hard and tense and parched, the colour of the face as a whole being yellow or black.

Let your food be your medicine, and your medicine be your food.

Medicine is of all the Arts the most noble; but, owing to the ignorance of those who practice it, and of those who, inconsiderately, form a judgment of them, it is at present behind all the arts.

The physician must be able to tell the antecedents, know the present, and foretell the future — must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm.

Fat people who want to reduce should take their exercise on an empty stomach and sit down to their food out of breath.... Thin people who want to get fat should do exactly the opposite and never take exercise on an empty stomach.

Whoever wishes to investigate medicine should proceed thus: In the first place, consider the seasons of the year and what effect each of them produces.

All diseases begin in the gut.