A Brilliant Brain

Biography

Galen was a Greek physician who became the most influential medical authority in the Roman Empire and Western medicine for over a millennium. His systematic anatomical studies and prolific writings created an authoritative framework that stifled medical progress, as his errors—including theories based on animal dissection rather than human anatomy—became unquestionable dogma. His brilliance lay in his methodology and persuasive synthesis of existing knowledge, even as that knowledge was fundamentally flawed.

Key Facts

• Performed public anatomical demonstrations in Rome that made him the emperor's personal physician
• Wrote over 500 treatises on medicine, but only about 100 survive today
• Believed the heart had pores allowing blood to flow between chambers—a theory that delayed understanding of circulation by 1,400 years
• Dissected pigs and apes instead of humans due to Roman law, leading him to extrapolate incorrectly to human anatomy
• His theory of four humors (blood, phlegm, yellow bile, black bile) dominated medicine until the 19th century