Frontispiece to De Humani Corporis Fabrica (On the Structure of the Human Body) The frontispiece to Vesalius’s pioneering work, published in 1543, shows him dissecting a corpse. This was a revolutionary new hands-on approach for physicians, who usually worked from a theoretical, rather than a practical, understanding of the body. Based on direct observation, Vesalius replaced ancient ideas drawn from Greek philosophy with a much more accurate account of the structure and function of the body.