Their post-graduate work was just as fine as their undergraduate work. They made the law of the world in the thirteenth century, and laid the foundations on which the philosophy and theology of the after-time have been built up. Strange as it may seem to many accustomed to give credence to far different traditions, they did the same thing in medicine. Take as a single example what they did for the regulation of medical education and practice. A law of the Emperor Frederick II, issued in 1241 for the Two Sicilies (Southern Italy and Sicily proper), required three years of preliminary training in the ordinary undergraduate course at the university before a man was allowed to take up medicine, and four years at medicine before he got his degree. But even this was not all; after graduation, a year of practice with a physician was required before he was allowed to practise for himself. If he were going to practise surgery an extra year of the study of anatomy was required. But it may {393} be said by those who cannot persuade themselves that the Middle Ages so far anticipated us: since they knew almost nothing of medicine and surgery, what did they spend their time at during these four years? The more we know about the details of that early teaching, the more we respect them and the more we admire the magnificent work of the old-time professors and their schools. Probably the most surprising feature of their teaching was surgery. We are rather likely to think that the development of surgery was reserved for our day. Nothing could be more untrue. The greatest period in the history of surgery, with the possible exception of our own time, is the century and a half from 1250 to 1400. What they taught in surgery we know not from tradition, but from the text-books of the great teachers which have been preserved for us, and which have been recently republished. Three men stand out pre-eminent: William of Salicet; Lanfranc, who taught at Paris, having been invited there from Italy, where he had been a pupil of William of Salicet, and Guy de Chauliac, to whom has been given by universal accord the title of Father of Modern Surgery. There is practically nothing in modern surgery that these men did not touch in their text-books. Perhaps the most surprising thing is to find that William of Salicet, in discussing his {394} cases, suggested that sometimes he succeeded in obtaining union by first intention by keeping his wounds clean. Alas for the surgery of succeeding centuries, Guy de Chauliac, a greater mechanical genius than William, insisted that union by first intention was an illusion and that it could only come through pus formation. Laudable pus became the shibboleth of surgery for centuries, imposed upon it by the genius of a great man. Most men think that they think, they really follow leaders, and so we followed blindly after Guy until Lister came and showed us our mistake.