Galen (Aelius Galenus) was a Roman physician of Greek descent, who lived in the 2nd century CE he was regarded in his time as a great expert on human anatomy. Roman law forbade autopsies from 150 BCE. Thus, Galen relied only on dissections of animals (mostly monkeys and pigs).
His research was conducted on both dead and live animals. Galen considered his conclusions to be binding also in relation to humans, because he believed that the structure of the body is similar. However, this approach has led to many misconceptions.
Galen’s general knowledge and authority were so great at that time that errors were accepted and weighed heavily on the science of the medieval period. Among other things, it was repeated after him that blood is born from food in the liver, bile is formed in the spleen, and air goes to the heart directly from the lungs.
Furthermore, Galen promoted the theory of Hippocratic “humors” that human behaviour and character traits are dictated by the level of body fluids:
- blood – optimist, extrovert
- black bile – melancholic, creative, kind and considerate
- yellow bile – choleric, full of energy and passion
- phlegmatic – phlegmatic, reliable, kind and emotional.
Nevertheless, Galen gained immense knowledge by conducting research, which gave him respect and authority in the field of medicine at that time. Galen mentioned, among other things, how to dress wounds, what herbs to use, what plants are a cure for disease and what food will restore strength and fitness to the wounded. Galen’s fame reached even the imperial court; Emperor Marcus Aurelius decided to appoint him as court physician.
