Medicine always claims that experience is the test of its operations. Plato therefore was right in saying that to become a true doctor, a man must have experienced all the illnesses he hopes to cure and all the accidents and circumstances he is to diagnose. … Such a man I would trust. For the rest guide us like the person who paints seas, rocks and harbors while sitting at his table and sails his model of a ship in perfect safety. Throw him into the real thing, and he does not know where to begin.