Galen: Figures from GCSE History

Galen Facts

Summary: Born in Anatolia (modern day Turkey) Galen was a philosopher and physician.
Born: 129 CE
Died: 216 CE (unconfirmed)
Biggest achievements: Galen’s most significant contributions to medicine were his development of the Theory of Opposites and dissection. Many of his theories were eventually disproved but others were instrumental in advancing medical knowledge and understanding such as the discovery that arteries carried blood, not air.

Who was Galen?

Claudius Galen was born in the town of Pergamum in Anatolia (modern-day Turkey) in 129 CE. His parents were Greek and his father was a successful architect. Galen had a keen interest in philosophy and enjoyed writing. It was not until he was 16 that he considered studying medicine. Pergamum held an important shrine to Asclepius, the Roman and Greek God of Medicine. Many travelled across the Roman Empire to Pergamum to worship at the shrine in an attempt to cure their illness. 

Galen’s education

Galen began his medical education at Pergamum but ended up studying in Alexandria, Egypt. The Great Library of Alexandria was the largest and most important medical institution in the ancient world. Egypt and the Middle East were pioneers in medical research at this time. Learning in Egypt also allowed Galen to view human organs. After death, Egyptians embalmed the bodies of their dead to help the soul get to the afterlife. The process required dissecting the corpse and removing internal organs. Rome forbade the practice of dissection and Galen never completed a dissection of a human body. 

In 157 CE, after nearly 10 years of studying, Galen returned to Pergamum fully educated as a physician. He became the chief physician at Pergamum's gladiator school. The extreme nature of the wounds Galen saw gave him more practical knowledge of human anatomy.

The Theory of Opposites

Galen was inspired by Hippocrates’ Theory of the Four Humours. He built upon this by creating a way of using the humours as a method of treatment. This was called the Theory of Opposites because it claimed that the “opposite” humour’s qualities could rebalance an excess of another humour. For example, having too much blood (dry and warm humour) could be treated by eating cucumber, a wet and cold substance. This transformed how the Four Humours were applied to a patient.

Galen’s contribution to medicine

Galen’s significant contributions to medicine were in the realm of anatomy. He dissected a wide variety of animals including apes, which are closely related to humans. He disproved the popular belief that the heart controlled the body by understanding the function of nerves. This is best shown in his famous “Squealing Pig” experiment. Galen carried out a public dissection of a pig. He cut the pig open alive and touched a nerve, forcing the pig to squeal. He then cut the nerve whilst the pig was still squealing. After this, the pig was unable to squeal. This categorically proved the brain controlled the body, not the heart. Through his dissections, he discovered that urine was produced in the kidney. Physicians in the ancient world believed the bladder produced urine. The most significant anatomical discovery was that arteries carried blood, not air. This was thousands of years before William Harvey confirmed this in An Anatomical Account of the Motion of the Heart and Blood in Animals. 

Impact of Galen’s work

Galen moved to Rome in 162 CE and became the most influential physician in the empire. In 168–169 CE, Galen served emperors Lucius Verus and Marcus Aurelius in a time of war as their personal physician. In 169 CE Galen returned to Rome to maintain the health of Marcus Aurelius as the sole emperor of Rome. After Aurelius died in 180 CE, Galen continued to serve the next two emperors, Commodus and Septimius Severus. This shows the reputation Galen had built as Rome’s leading physician. He wrote up to 300 works, of which 150 completely or partially survived.

After Galen died in c.216 CE, his written works continued to be widely circulated across the Roman Empire. Alexandria included his teachings in their medical course by 500 CE and his work was widely translated and distributed across the Middle East. In 850 CE, Ḥunayn ibn Isḥāq, a court physician in Baghdad, translated 129 of Galen’s works into Arabic.

Galen’s medical practices and anatomical studies continued to be fundamental in how people perceived the causes of disease in the Middle Ages. The Church supported the Theory of the Four Humours, which was the foundation of Galen’s beliefs. Whilst the Church disapproved of Galen’s use of dissection, they stated that his anatomical findings were correct. This aimed to deter others from wanting to practice dissection. Galen and Hippocrates’ theories were taught to all physicians during their university education. This demonstrates how highly regarded Galen’s ideas of medicine were.

In the Renaissance, Galen’s theories were finally disproved. The Theory of the Four Humours became less relevant in an environment of scientific discovery. Vesalius discovered that Galen had made over 300 mistakes in his descriptions of the human anatomy. Harvey also proved that if the liver produced blood, as Galen had argued, it would have to produce 1,800 litres of blood a day. Despite their findings, many in the medical profession refused to believe that Galen was incorrect. They even argued that the human anatomy must have changed from the times of Galen. By the 18th century, Galen’s theories were no longer widely believed.

Death 

Galen died in c.216 CE. His cause of death is unknown.

Useful reading

• Learn more about Hippocrates and the Theory of the Four Humours