PPOCRATES (460 – 370 bs.)Greek physician who founded a medical school on Cos. This school produced more than 50 books, as well a system of medical methodology and ethics which is still practiced today. Upon being granted their M. D. degrees, new doctors still swear a so-called Hippocratic oath. In On Ancient Medicine, Hippocrates stated that medicine is not philosophy, and therefore must be practiced on a case-by-case basis rather than from first principles. In The Sacred Disease, he stated that epilepsy (and disease in general) do not have divine causes. He advocated clinical observations, diagnosis, and prognosis, and argued that specific diseases come from specific causes. Hippocrates's methodology relied on physical examination of the patient and proceeded in what was, for the most part, a highly rational deductive framework of understanding through observation. (An exception was the belief that disease was caused by "isonomia", an imbalance in the four humors originally suggested by Empedocles and consisting of yellow bile, blood, phlegm, and black bile.) The Hippocratic corpus of knowledge was widely distributed, highly influential, and marked the rise of rationality in both medicine and the physical sciences.
GALEN (130 – 200 ca.)
Greek physician considered second only to Hippocrates of Cos in his importance to the development of medicine, Galen performed extensive dissections and vivisections on animals. Although human dissections had fallen into disrepute, he also performed and stressed to his students the importance of human dissections. He recommended that students practice dissection as often as possible. He studied the muscles, spinal cord, heart, urinary system, and proved that the arteries are full of blood. He believed that blood originated in the liver, and sloshed back and forth through the body, passing through the heart, where it was mixed with air, by pores in the septum. Galen also introduced the spirit system, consisting of natural spirit or "pneuma" (air he thought was found in the veins), vital spirit (blood mixed with air he believed to found in the arteries), and animal spirit (which he believed to be found in the nervous system). In On the Natural Facilities, Galen minutely described his experimentation on a living dog to investigate the bladder and flow of urine. It was Galen who first introduced the notion of experimentation to medicine. Galen believed everything in nature has a purpose, and that nature uses a single object for more than one purpose whenever possible. He maintained that "the best doctor is also a philosopher," and so advocated that medical students be well-versed in philosophy, logic, physics, and ethics. Galen and his work On the Natural Faculties remained the authority on medicine until Vesalius in the sixteenth century, even though many of his views about human anatomy were false since he had performed his dissections on pigs, Barbary apes, and dogs. Galen mistakenly maintained, for instance, that humans have a five-lobed liver (which dogs do) and that the heart had only two chambers (it has four).
MONDINO DE LUZZI (1275-1326)
Italian physician who marked the revival of medical practice in the West following the Dark Ages. Arabian and Persian doctors, the greatest of whom was Avicenna, had continued the Hippocratic and Galenic traditions, but their works remained in the framework of Greek medicine and did not produce new methodologies. Although Mondino de' Luzzi is historically important as one of the first physicians of note following the Dark Ages, his medical procedures were, in fact, a step backwards. He taught his students while seated on an elevated chair, and employed a barber surgeon to perform the actual dissections. He believed in dissecting from the inside out, since internal organs rot the most quickly. In the process, he inevitably destroyed parts of the body in the process. Furthermore, Mondino de' Luzzi blindly accepted Galen's anatomy, even when a simple dissection would have conclusively proven him to be at odds with actual observations. He wrote a compendium of anatomy, which was basically a guide for understanding Galen. This represented a regression from scientific procedures, and stands out in sharp distinction to Grosseteste's and Roger Bacon's extensive experimentation and questioning of established authorities which were being undertaken in approximately the same period. Unfortunately for medicine, as well as science at large, Mondino de' Luzzi's methods became standard practice in medical schools until they were eventually replaced by the sound observational and experimental practices of Vesalius.
VESALIUS (1514 – 1564)
Flemish anatomist who founded the sixteenth century heritage of careful observation characterized by "refinement of observation." Vesalius changed the organization of the medical school classroom, bringing the students close to the operating table. He demonstrated that, in many instances, Galen and Mondino de' Luzzi were incorrect (the heart, for instance, has four chambers). He conducted his own dissections, and worked from the outside in so as not to damage the cadaver while cutting into it. Vesalius also wrote the first anatomically accurate medical textbook, De Humani Corporis Fabrica (1543), which was complete with precise illustrations. Vesalius's careful observation, emphasis on the active participation of medical students in dissection lectures, and anatomically accurate textbooks revolutionized the practice of medicine. Through Vesalius's efforts, medicine was now on the road to its modern implementation, although major modifications and leaps of understanding were, of course, necessary to make its practice actually safe for the patient.
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