Herophilus of Chalcedon (c. 330-c. 260 BC)

Greek physician who was the world's first careful anatomist. He practiced in Alexandria, where human dissections were permitted, even performing some in public. His discoveries, recorded in On Dissections, included the differentiation between sensory and motor nerves and observations of the liver, retina, and ovaries. He subscribed to the humoral pathology, and believed bloodletting had therapeutic value.