About 460-380 B.C. Born on the Greek island of Cos, Hippocrates was the fore most physician of his time. He rejected his contemporaries' ideas of illness being caused by evil spirits and divine disfavour, in favour of a rational physical explanation. He accurately described the symptoms of disease such as pneumonia and epilepsy. He espoused rest, good diet, fresh air and good hygiene in the management of disease. He was the first physician to conclude that thoughts, feelings and ideas originated in the brain.
He founded a medical school on Cos, and developed the oath that bears his name. He is commonly regarded as the "Father of Medicine"
See Wikipedia:Hippocrates and for collections of his writings at MIT
see Hippocratic oath