Claudius Galen was the most famous doctor in Ancient Rome. His main work was on anatomy and use of the Hippocratic Four Humours theory. Although he died in the 2nd century AD, his work was still used as the standard text in Europe in the 15th century AD. Galen’s ideas were viewed as unchallengable for over 1000 years, and it was not until the Renaissance and the work of men such as Andreas Vesalius that Galen’s domination of medicine was ended.


Galen was extremely influential in his own lifetime

Galen broke new ground on anatomy

Anatomical knowledge had progressed little since the time of the Egyptians, and the Egyptian theory that the heart controlled the body was still accepted. Using dissection of animals Galen proved that the brain controlled the body. Galen also did work on the bone structure of the body as well as the organisation and function of organs. He based his work on the dissection of animals as human dissection was against the religious beliefs of the Romans in the need for a perfectly preserved body in the afterlife.

Galen dissects pigs

Galen wrote many books on anatomy and medical work

Galen was an extremely forceful and effective writer. He wrote in a manner that dealt with opposition to his ideas, and made it seem as if his ideas had to be correct as they were based on investigation. He wrote more than 60 books, including titles on anatomy, the need for dissection and how to use the four humours to treat patients. The power of these books made it difficult for anyone to challenge his ideas.

Galen was popular with Christians and Muslims

The collapse of the Roman Empire left religion in charge of medicine

When the Roman Empire ended in the 5th century AD, the Christian Church in Europe and Islam in the Arab world became the dominant forces in medicine. Galen had argued that the human body was the perfect creation of a single god. Although he was not a Muslim or a Christian, Galen’s belief in one god as creator made his ideas acceptable to both Islam and Christianity. The two religions adopted his ideas and promoted Galen’s work as the truth.

Medical schools and hospitals were religiously controlled

The two religions developed hospitals and medical schools from the 9th century AD onwards. These were built on the idea of Galen, and student doctors were taught Galen’s ideas as facts that could not be challenged. Even when dissection was allowed in the Christian medical schools such as Paris and Salerno in Sicily, the tutor would simply read out Galen’s work as a student dissected. The idea was not to discover new ideas, but to use the dissection to prove that Galen was right.

Much of Galen’s work was actually lost in Europe

Many of Galen’s most important books were destroyed when the Roman Empire collapsed

When the Barbarians burnt Rome in 410AD, many of the copies of Galen’s work were destroyed. All across Europe collections of books and manuscripts perished in the anarchy that followed the end of the Roman Empire. Although copies of Galen’s books survived in the Arab world these were not available to doctors in Europe for hundreds of years. Therefore acceptance of Galen’s ideas was based on limited access to his works, and his reputation and possession of religious support became more important than new research.

Access to Galen’s lost works came from translation out of Arabic

During the centuries after 1100 Europeans regained access to the works of Galen by translating them from Arabic. This meant that they had undergone a many as three translations from the original Latin, into Greek then into Arabic before finally being translated back into Latin or into French or Italian. Much of the clarity of Galen’s thought was thus lost, and since the Arabic doctors viewed Galen in the same idealised fashion that the Christians did, their books were full of praise for him. 

Convincing people to abandon Galen was very difficult 

Even when challenges began, the process was slow

Challenges to the supremacy of Galen became strong during the Renaissance in Europe. The German doctor Paracelsus publicly stated in 1572 that he believed Galen was a liar, and started to use dissection to actively research human anatomy rather than just to prove Galen right. However Paracelsus did not change the accepted wisdom of centuries overnight. He was attacked as a heretic and the majority of doctors refused to accept his claims. 

The work of Andreas Vesalius was crucial

One of the most powerful claims of Galen was his theory of the circulation of blood in the human body. Galen claimed that there were holes in the Septum of the heart. He said that it was these holes that allowed blood to pass around the body. Using modern microscopes and previously unacceptable dissections Vesalius proved that there were no holes in the Septum. 

Galen's internal workings diagram

More challenges to Galen were made

Once the existence of the holes had been shown to be false, Galen’s credibility began to be shattered, and doctors went on to show how much of the rest of his work was wrong. His work on the womb was shown to be wrong as he had relied on dissections of dogs. His explanation of the workings of the human body was largely based on his assertion that there was a network of blood vessels under the surface of the brain which he called the ‘wonderful network’. These did not exist in humans however. Galen had relied on his dissections of animals, and he was again proved wrong. Galen’s claim that the human jawbone had two bones was based on the dissection of monkeys, and again was shown to be wrong by doctors in the Renaissance.

Galen was eventually discarded

Galen’s ideas were not abandoned by doctors in the face of these challenges. The explanation offered by Vesalius took decades to be accepted, and even when William Harvey proved how blood flowed round the body and showed off his work in 1616, it took many years to be accepted. At the time of the death of King Charles II in 1685, the ideas of Galen remained powerful and were relied upon by his doctors.

In short

Galen’s ideas remained powerful for so long because:

·       Galen’s work had been extremely influential during his lifetime

·        He had broken new ground in the study of human anatomy

·        He wrote very persuasively

·        Galen was accepted by Christianity and Islam

·       Galen was taught in the hospitals and medical schools which the churches controlled

·        Dissection was used to prove Galen right not to discover new things

·        Access to the full works of Galen was not possible in Europe

·        Challenges to Galen often led to severe criticism from other doctors

·        Even when he was shown to be wrong people were reluctant to abandon his ideas

Last modified: Monday, 13 August 2012, 2:24 PM
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