Claudius Galen held back medical progress for centuries due to his belief that the body was made up of four humors: blood, phlegm, yellow bile, and black bile. Galen believed that illness was caused by an imbalance of these four humors, and that the goal of medicine was to restore this balance.
Galen’s theory led to the practice of bloodletting, which was used to treat a wide variety of conditions. Bloodletting was often harmful and sometimes fatal, yet it remained a popular treatment for centuries due to Galen’s influence.
Galen’s ideas about the human body were largely based on his observations of animals, which led to many errors in his understanding of human anatomy.
The Scientific Revolution and the development of modern medicine finally began to supersede Galen’s influence in Europe during the Renaissance (14th century CE), when physicians began to question his ideas and develop new ones.
The legacy of Claudius Galen is both positive and negative: while his ideas held back progress for centuries because they were based on incorrect assumptions about human anatomy and physiology (which were not fully understood until modern times), his work also laid down important foundations that helped shape modern medicine
