Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations. And by this, in an especial manner, we acquire wisdom and knowledge, and see and hear and know what are foul and what are fair, what are bad and what are good, what are sweet and what are unsavory…. And by the same organ we become mad and delirious, and fears and terrors assail us….All these things we endure from the brain when it is not healthy….In these ways I am of the opinion that the brain exercises the greatest power in the man.

Anyone wishing to study medicine must master the art of massage.

Everything in excess is opposed to nature.

Each of the substances of a man's diet acts upon his body and changes it in some way and upon these changes his whole life depends.

To really know is science; to merely believe you know is ignorance.

Walking is a man's best medicine.

About medications that are drunk or applied to wounds it is worth learning from everyone; for people do not discover these by reasoning but by chance, and experts not more than laymen.