The Greek physician of Kos, remembered as the father of medicine, under whose name the roughly sixty texts of the Hippocratic Corpus gathered one of the earliest sustained insistences that disease has natural rather than divine causes — though almost nothing about the man can be securely known, the corpus was written by many hands over generations, and the famous Oath bearing his name cannot confidently be traced to him.
He is called the father of medicine, and we are not sure he wrote a single word that survives. Hippocrates of Kos was a real physician of the fifth century BC, but almost nothing about his life is certain, and the sixty-odd medical texts that bear his name were composed by many different writers across generations. What gathered under that name was an idea, not a biography: that illness has natural causes, not divine ones, and can be studied by watching the patient rather than appealing to the gods. The texts said the falling sickness was no more sacred than any other disease. That single move, separating medicine from magic, is why one half-known man became the name medicine was built on.