The great influence of Galen

By Suneet Sood

In every profession there is often one name that stands out. Cricket has Bradman, boxing has Muhammad Ali, science has Einstein, literature has Shakespeare, crime has Jack the Ripper, the internet has Google, and DC Comics has Superman. Medicine has Galen. Today few of Galen’s views are accepted, but for most of the last two thousand years Galen towered over medical science as not even Hippocrates did.

The story starts about two thousand years ago. BC, tired of adding her name to every passing year, handed over the calendar to AD. If you threw a brick at random, chances were you would hit an emperor. Men grew long beards for want of anything better to do.1 Science was weak, malnourished, and often despised. Medicine had hardly progressed from the days of Hippocrates, and anybody who could say “four humors” was considered a physician.

Into this world came Galen (130 AD - 200 AD), and rewrote medicine. He wrote over twenty thousand pages of medicine, and although he wrote on paper, his writings endured as if he had written on stone.2 For an incredible thousand years and more, anybody who dared challenge Galen’s teachings was frowned on, considered insane, or worse. Michael Servetus was even burnt at the stake for differing with Galen 1200 years later!3 Nobody before him had had such a lasting influence on the progress of medical science; nobody ever would.

The famous physician. Galen was born in Pergamon, a small town in Asia Minor. Asia Minor now exists as Turkey; Pergamon now exists as nothing. Little is known of his parents, except that his father was named Aelias Nikon and was poor at photography, while his mother used to bite servants. Fortunately, we know a lot about Galen himself. As a teenager he wrote three books, and was justifiably considered a genius. Galen traveled to Egypt for studying and sightseeing. Cleopatra had died a hundred years earlier, and Galen came to Rome after studying. As his practice grew, Galen became the official physician to the gladiators of Rome. Gladiators were always poking spears at each other, and Galen learnt a lot about wounds.4 Unfortunately Galen himself was always poking ridicule at others, and in due course someone gave Galen a piece of his mind. Galen went into a sulk and returned to Pergamon till Marcus Aurelius, the emperor of Rome, offered Galen a pacifier5 and called him back to Rome. Galen practiced in Rome for several years and served three kings.6 By the time he died, he had established himself as then the world’s leading physician, surgeon, anatomist, physiologist, pathologist, neurologist, nutritionist, and pharmacologist, as also the world’s leading writer.7 Some of his books include “On the affections of the mind”, “On Prognosis”, “Whether blood is contained in the arteries in nature”. He even wrote a book about his books (“On his own books”).8

The observer. Galen was unquestionably a genius, and knew more medicine than did most of his contemporaries put together. He had incredible powers of observation, and was thus able to assimilate great experience. As a gladiatorologist,9 his surgical mortality was less than a tenth that of his predecessor’s, due to the fact that he paid meticulous attention to the wounds in his patients. (He also had an excellent set of pharmaceutical preparations, all his own, no doubt generating huge royalties.) He called wounds “windows into the body”, and would spend hours with his eyes glued to a fresh wound, trying to see what was going on inside. Mostly what he saw was inflammation. (Celsus had already described calor, rubor, dolor, tumor as the signs of inflammation; Galen added his own: functio lasea.) A skeptic once called Galen to look at a patient. Galen, out of the corner of his eyes, saw the patient’s stools, which indicated a liver disorder. Before even examining the patient, Galen pointed at the patient’s liver and said dramatically, “Here lieth the malady” and began cupping it. The skeptic, unaware that Galen had cheated by peeking at the feces, became a devout follower of Galen for life. Another time he came to see a young woman wasting away.10 During a long history-taking Galen, observant as always, noted that her cheeks would redden at the word “Pylades”. Pylades those days was a well-known actor whose curly hair, smoldering eyes, and superhuman stunts on stage made many a female heart perform acrobatics. Galen tested her with several other names at random, but no reddening of cheeks occurred.11 Galen had made his diagnosis: “It’s love!” he declared, astounding all and causing the patient no little embarrassment. Galen also performed operations, including removal of cataracts, which he did with a small wire. The slightest slip could cause blindness, and cataract surgery after Galen was not performed for another two thousand years!

The showman. Yet not all of Galen’s fame was because of his medical skills alone. He never passed a chance to praise himself and criticize others. “I am the greatest!” He would say.12 Galen also gave several lectures and demonstrations, especially in anatomy. Human dissection was prohibited, but Galen believed the ape was good enough.13 He often gave a deliberately poor prognosis to his patients, realizing that if the patient lived, he was a genius, and if the patient died, his prediction was correct. Galen was also fond of cupping as a method of treatment. Cupping involved the attaching of suction cups to various parts of the body surface. It is doubtful if Galen believed that cupping actually worked, but the cups produced satisfying popping sounds on removal, and the observers always felt that the brilliant doctor was effectively sucking out the disease. An even more dramatic therapy was bloodletting: Galen used to drain blood as a treatment for several illnesses. In this therapy, Galen was an expert: he could remove just enough blood to impress the onlookers, but just short of the amount needed to kill the patient. Bloodletting continued well into the 18th century, and a physician named Benjamin Rush (1745-1813) become the best-known bloodletter of all time, prescribing bloodletting for any disease from acne to Zellweger syndrome.14

The researcher. Galen was always willing to try out new experiments in order to test his theories. In an era where everybody thought that the arteries were full of gas, he wandered with many strings and one tube, tying ape arms at different levels and cannulating ape hearts. His experiments with many strings and one tube proved that arteries contained blood, not air, and that the blood flowed outwards from the heart. In an era where everybody thought that reasoning and consciousness originated in the heart, he wandered with a knife, puncturing apes. He would jump on an unsuspecting ape and cut off the recurrent laryngeal nerves. The astonished ape, never treated thus before, would be speechless, and Galen would declare, “This proveth that the commands for speech originateth above the larynx, not below!”. His monkey dissections demonstrated a rich network of veins (“rete mirabile” in the brain, and he was convinced that human thought originated here. “And yonder,” he would add, pointing dramatically at the great cerebral vein in a dead ape, “is my vein, the vein of Galen!”

Galen and Hippocrates were the two icons of early medicine, alike in respecting the “four humors” theory of medicine, but different in many ways. If Hippocrates was the Father of Medicine, Galen was the Father of Medical Research. Where Hippocrates hesitated to intervene (“Do no harm”), Galen jumped in (Just do it!). Where Hippocrates preferred money, Galen preferred fame. Hippocrates was a calm and peaceful man. The word “Galen” means “calm and peaceful”, but to call Galen calm and peaceful would be to put an unfair strain on the English language.


  1. There was no television
  2. Actually, he should have written on stone. Two thirds of his writing was destroyed in a fire
  3. That was rather harsh
  4. He was probably the world’s first specialist at Sports Medicine
  5. Marcus promised him untold riches and, which Galen valued more, the right to shout at anybody by royal decree
  6. Marcus Aurelius, who was a philosopher, Commodus, who was toilet trained, and Septicemius, who died
  7. Any Faculty of Medicine would have employed him
  8. He wanted to write the “Canon of Medicine”, but his father, Nikon, refused permission, so later Ibn Sena (Avicenna) wrote this book
  9. This specialty is now obsolete
  10. The young woman was wasting away, not Galen
  11. Interesting that the first ever randomized, controlled clinical trial in medicine was conducted on one woman with blushing disorder
  12. Muhammad Ali (Cassius Clay), the boxer, later used this phrase extensively, since Galen forgot to copyright it
  13. Why should there be one law for humans and another for apes?
  14. Rush was less skilled than Galen. After killing half the population of Philadelphia, Rush joined politics, and signed the Declaration of Independence