It is usually presumed that the practice of medicine was on a very low plane during the Middle Ages, and that while only little was known about medical science, the methods of practicing the medical art were crude, as befitted an earlier time in evolution before modern advances had come. Any such impression is founded entirely on ignorance of the conditions which actually existed. In his studies in the history of anatomy in the Middle Ages, Von Töply quotes the law for the regulation of the practice of medicine issued by the Emperor Frederick II. in 1240 or 1241. The Law was binding on the two Sicilies, and shows exactly the state of medical practice in the southern part of Italy at this time. Everything that we think we have gained by magnificent advances in modern times is to be found in this law. A physician must have a diploma from a university and a license from the government; he must have studied three years before taking up medicine–then three years in a medical school, and then must have practiced with a physician for a year before he will be allowed to take up the practice of medicine on his own account. If he is to take up surgery, he must have made special studies in anatomy. The law is especially interesting because of its regulation of the purity of drugs, in which it anticipates by nearly seven centuries our Pure Drug Law of last year.
James J. Walsh, The Popes and Science (1908)