Hippocrates of Cos is regarded as the father of Western medicine for basing the art of healing on rational principles and liberating it from divine causality and superstition. He perceived man as a whole entity, and health as resulting from multiple factors, including environmental and dietary ones. The Hippocratic Corpus, a collection of works left by Hippocrates and his students, deals with practically all branches of medicine and systematically records clinical symptoms and treatments, always in line with the principle “to do good, or [at least] to do no harm”. The Hippocratic Oath remains the guide to medical ethics and practice to this day.
