Andreas Vesalius believed surgery had to be grounded into anatomy. At that time anatomy had little importance. Vesalius performed many dissections himself. He made charts of the nervous system and blood to aid his students. Vesalius then wrote a pamphlet on blood letting. After blood letting was the standard treatment for many diseases, it lasted many years. In the pamphlet Vesalius highlighted how important medicine was.

In 1539 a judge became interested in Vesalius's work. He granted Vesalius the bodies of executed criminals. He then dissected and compared each body. This was a positive turn in Vesalius's career in Anatomy.