Ancient Greek Medicine - Alexandria

Alexandria

Following Theophrastus ( d.286 BC ), the Lyceum failed to produce any original work. Though interest in Aristotle's ideas survived, they were generally taken unquestioningly. It is not until the age of Alexandria under the Ptolemies that advances in biology can be again found. The first medical teacher at Alexandria was Herophilus of Chalcedon, who corrected Aristotle, placing intelligence in the brain, and connected the nervous system to motion and sensation. Herophilus also distinguished between veins and arteries, noting that the latter pulse while the former do not. He did this using an experiment involving cutting certain veins and arteries in a pig's neck until the squealing stopped. In the same vein, he developed a diagnostic technique which relied upon distinguishing different types of pulse. He, and his contemporary, Erasistratus of Chios, researched the role of veins and nerves, mapping their courses across the body.

Erasistratus connected the increased complexity of the surface of the human brain compared to other animals to its superior intelligence. He sometimes employed experiments to further his research, at one time repeatedly weighing a caged bird and noting its weight loss between feeding times. Following his teacher's researches into pneumatics, he claimed that the human system of blood vessels was controlled by vacuums, drawing blood across the body. In Erasistratus' physiology, air enters the body, is then drawn by the lungs into the heart, where it is transformed into vital spirit, and is then pumped by the arteries throughout the body. Some of this vital spirit reaches the brain, where it is transformed into animal spirit, which is then distributed by the nerves. Herophilus and Erasistratus performed their experiments upon criminals given to them by their Ptolemaic kings. They dissected these criminals alive, and "while they were still breathing they observed parts which nature had formerly concealed, and examined their position, colour, shape, size, arrangement, hardness, softness, smoothness, connection."

Though a few ancient atomists such as Lucretius challenged the teleological viewpoint of Aristotelian ideas about life, teleology (and after the rise of Christianity, natural theology) would remain central to biological thought essentially until the 18th and 19th centuries. In the words of Ernst Mayr, "Nothing of any real consequence in biology after Lucretius and Galen until the Renaissance." Aristotle's ideas of natural history and medicine survived, but they were generally taken unquestioningly.