Hippocrates of Cos or Hippokrates of Kos ( c. 460 BC – c. 370 BC) was an ancient Greek physician. He is referred to as the father of western medicine. He is first person to believe that diseases were caused naturally, not because of superstition and gods.
The ancient Greeks initially regarded illness as a divine punishment and healing as, quite literally, a gift from the gods. However, by the century BCE, there were attempts to identify the material causes.