Andreas Vesalius (1514-1564) was the first to insist on dissections, on exact physiological experiment and direct observation.
Vesalius discovered many errors in Galen’s work and revealed his evidence to discredit Galen and to show that Galen’s description of curved human thighbones, heart chambers, segmented breast bones, etc, better matched the anatomy of apes than humans.
Vesalius dissected the cadavers himself. This contravened the usual procedure, on which the professor read from a Galenic text while the body was opened by a menial or prosector. Vesalius began to employ drawings to clarify the various structures of the body.
Vesalius detailed more than 200 discrepancies between actual human and Galen’s descriptions, Time after time, Vesalius showed that what every doctor and surgeon in Europe relied on fit better with apes, dogs, and sheep than human body.
Vesalius De Humani Corporis Fabrica was completed and published his magnificent anatomy book in 1542.
Ultimately the scientific study of anatomy became accepted as the avenue of increasing the knowledge of this discipline and the practice of medicine.
With the rise of modern science, the approach that Vesalius pioneered became the standard for medicine. Physicians followed him into the body dissecting it as a way of understanding how it worked.
Andreas Vesalius: modern founder of anatomy