Vesalius

After receiving his medical degree in 1537, Andreas Vesalius began lecturing on surgery and anatomy at the University of Padua. To further his knowledge, he personally dissected cadavers, a task that others in his position would have delegated to an assistant. Through this work Vesalius became convinced that the anatomical theories of the Greek physician Galen, whose ideas had been accepted as authoritative for more than 1,000 years, were not correct. Although Vesalius had begun his career as a Galenist, his hands-on experience led him to believe that Galen's descriptions of the human body were based on dissections of pigs, dogs, and other animals rather than humans, a procedure that was prohibited during Galen's time. Vesalius compared Galen's anatomical texts with his own observations made during dissections. After five years spent compiling his findings, in 1543 he published De humani corporis fabrica (On the Structure of the Human Body), which was the most accurate and comprehensive anatomy textbook to date and included artists' engravings based on Vesalius's own drawings. By relying on careful observation instead of received wisdom, Vesalius transformed the field of anatomy, as well as medicine and biology.