Roman knowledge about the body and disease

The Romans did not allow dissection of human bodies, so they were limited in what they could find out about human anatomy. They also rejected many Greek ideas about medicine. These factors slowed down their progress, but they continued to explore new ideas about the causes and prevention of disease.


Roman doctors learned a lot about the human body as they tended gladiators wounded in the amphitheatres. However, dissection of humans was forbidden in the Roman empire, so Roman anatomists such as Galen had to rely mainly on dissections of animals to further their knowledge. Galen recommended dissecting monkeys that walked on two legs, like men.


Galen as depicted in a book by the 16th-century French surgeon Ambroise Paré

He did manage to work a little with the human body, and described how he had human corpses to dissect when he found a hanged criminal, and when a flood washed some bodies out of a cemetery. Despite this, he made various errors in his analysis of how bodies work.

Galen's books show a good knowledge of bone structure. He also studied the lungs, the muscles, the heart and blood and the nervous system. He conducted experiments on pigs, and when he cut the spinal cord in different places he realised how the nervous system takes messages from the brain to the muscles.

Galen accepted the Greek theory of the four humours [Four humours: Four bodily fluids - yellow bile, black bile, blood and phlegm - used in ancient times to analyse and describe people's state of health. ] as the cause of disease. However, the Romans did not continue the Greeks' investigations into disease and rejected Greek ideas, so Roman knowledge of disease did not progress.

Roman ideas about disease were muddled. For example:

  • Crinas of Massilia thought illness was caused by the stars (astrology).
  • Varro blamed creatures too tiny to be seen.
  • Columella blamed poisonous vapours in the swamps.

All these ideas survived until the 19th century.

Anatomical errors in Galen

Galen based most of his information about anatomy on what he saw when he dissected the bodies of animals. This led him to make mistakes. Some of his errors were:

  1. He thought that muscles attach to the bone in the same way in humans and in dogs.
  2. He thought that blood was created in the liver. He realised that it flowed round the body, but said it was burned up as fuel for the muscles.
  3. He thought he saw holes through the septum, which allowed the blood to flow from one side of the heart to the other.
  4. He made mistakes about the blood vessels in the brain.
  5. He thought the human jaw-bone was made up of two bones, like a dog's.
  6. He was mistaken about the shape of the human liver.

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