Galen, properly Claudius Galenus c.130-c.201AD
Greek physician

Born in Pergamum in Mysia, Asia Minor, he studied medicine there and at Smyrna, Corinth and Alexandria. He was chief physician to the gladiators in Pergamum from AD157, then moved to Rome and became friend and physician to the emperor Marcus Aurelius. He was also physician to emperors Lucius Aurelius Commodus and Lucius Septimius Severus. He was a voluminous writer on medical and philosophical subjects, and collated all the medical knowledge of his time, especially promoting the work of Hippocrates. An active experimentalist, and dissector of animals, he elaborated a physiological system whereby the body's three principal organs - heart, liver and brain - were central to living processes, and he was the first to use the pulse as a diagnostic aid. Although not a Christian, he was a monotheist and thus his work was easily assimilated into Christian orthodoxy in the centuries after his death. His De usu partium ('The Uses of the Parts') was in essence a hymn to the creator, whereby the organs of the body were seen as perfectly adapted to the functions which they served. He was long venerated as the standard authority on medical matters.

Bibliography: G Sarton, Galen of Pergamon (1954)