Galen

Galen (129-c. 216), famous physician and renowned philosopher of classical Greece. He constructed a philosophical theory of medicine that formed the basis of Western medicine until the 17th century, and remains influential in the Islamic world and in popular ideas on health today (see Classical Medicine; Western Philosophy).

Galen was born in Pergamum (Bergama, in modern Turkey) and received a traditional education in the liberal arts. Having chosen medicine as his profession at the age of 16, he pursued medical studies in Pergamum, then in nearby Smyrna (now İzmir), and finally in Alexandria. At the age of 28 Galen returned to Pergamum as physician to the gladiators.

In 162 Galen moved to Rome, where he affected many cures on prominent public figures. He also gave public lectures on medicine in which he dissected goats, pigs, and apes to demonstrate features of the anatomy and physiology of the body. Galen used these demonstrations to convince his audience that medical knowledge was acquired by searching for the rational causes of observable effects. Using this approach, Galen made many important discoveries. He identified the seven pairs of cranial nerves; he observed how the brain controls the voice; and he proved that the arteries contain blood.

Galen left Rome in 166. Two years later he was invited to join Emperor Marcus Aurelius and his army in northern Italy, where he became physician to the imperial family. He continued in imperial service under the emperors Lucius Aelius Aurelius Commodus and Lucius Septimius Severus.

Galen was a follower of Hippocrates, but he believed that the Hippocratic texts on medicine required further explanation. He maintained that Hippocratic medicine could be made more rational and systematic by presenting it as a science in which medical knowledge was logically demonstrated to be true.

Galen believed that the body was made up of four humours: blood, phlegm, black bile, and yellow bile. Each of these humours corresponded to one of the four elements and its qualities. Blood was associated with air, being hot and wet; phlegm with water, being cold and wet; yellow bile with fire, being hot and dry; and black bile with earth, being cold and dry. These humours linked the body with its physical environment and the underlying principles of the material world.

Each body had a unique mixture of humours, which gave each person a unique temperament. A person with a preponderance of phlegm was naturally phlegmatic, or sluggish and apathetic. A dominance of blood produced a sanguine person who was bold and confident. A bilious person, with a preponderance of yellow bile, was hot tempered and irascible. Somebody with an excess of black bile was melancholic, or depressed and gloomy. This theory explained psychological characteristics in terms of the physical make-up of the body. Galen said that a body was healthy when its particular mix of humours was in equilibrium, and was ill when its humours were in disequilibrium.

Galen maintained that the life-giving functions of the body were performed by four major systems in the body. The body was nourished by blood produced in the liver and distributed through the veins. It was animated by a different sort of blood manufactured in the heart and sent to all parts of the body through the arteries. It was made sentient by a special substance produced in the brain and distributed through the body by the nerves. Finally, the body procreated by means of seed generated within the sex organs.

By localizing these functions within specific organs, Galen directed attention to the form and function of each part of the body. In particular, he was keen to show how the structure of each part corresponded perfectly to its action. By so doing, Galen believed that he was exhibiting its inherent beauty and the excellent provision that God had made for it.

In medical practice, Galen recommended that physicians observe their patients closely and look for signs that indicated the underlying causes of illness. Once the physician had understood an illness in terms of its causes and effects, he was then in a position to offer a prediction as to its outcome and suggest an effective therapy. Galen advised physicians to take special note of the patient’s pulse, as this was a valuable indicator of what was going on inside the body.

Galen upheld the Hippocratic belief in the healing power of nature. He intervened only to encourage nature’s efforts at restoring the body’s humoral balance. To this end he advised his patients on their diet, sleeping patterns, sexual activity, and living circumstances. He also prescribed tried and tested medicines according to the Hippocratic belief that illnesses were cured by their opposites. For example, he prescribed hot and wet remedies for cold and dry illnesses.

Nearly 500 works are attributed to Galen, including texts on medicine, epistemology, logic, and philology, as well as commentaries on Hippocrates, Plato, Aristotle, and Epicurus. Many of these works were subsequently translated into Syriac (Christian Aramaic), Arabic, Hebrew, and Latin. They embody Galen’s ideal of the good doctor as a philosophically minded scholar and an experienced practitioner, an ideal that has endured to this day.