Opposites are cures for opposites.

But medicine has long had all its means to hand, and has discovered both a principle and a method, through which the discoveries made during a long period are many and excellent, while full discovery will be made, if the inquirer be competent, conduct his researches with knowledge of the discoveries already made, and make them his starting-point. But anyone who, casting aside and rejecting all these means, attempts to conduct research in any other way or after another fashion, and asserts that he has found out anything, is and has been victim of deception.

Where prayer, amulets and incantations work it is only a manifestation of the patient's belief.

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.

Just as food causes chronic disease, it can be the most powerful cure

Of several remedies, the physician should choose the least sensational.

Eunuchs do not take the gout, nor become bald.