Galen (c.129 A.D. – c. 216)
Galen was one of the most prominent ancient physicians as well as a philosopher (though most of his philosophical writings are lost). Nonetheless, his philosophical bent is quite evident in his practice of biological science. He was a well-read scholar who combined extensive erudition with 'cutting edge' observational practice to completely change the understanding and teaching of medicine. His position as the leading authority in medical theory extended for at least fourteen hundred years.
From Internet Encyclopedia of Philosophy
See also Wikipedia
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