Hippocrates stands at the head of this chronicle less as a single author than as the name attached to a revolution in thought. The treatises gathered under his name insist, against the temper of their age, that sickness arises from natural causes and may be studied, predicted, and treated by natural means.
Whether or not the historical man wrote a word of the Corpus that bears his name, the doctrine is his legacy: that the physician's task is to observe the patient closely, to record the course of the illness honestly, and above all to do no harm.