The belief that health consists in the maintenance of the proper proportion between the opposite constituents of the body is a common-place of ancient medicine which can be traced back to Alcmaeon of Croton, a disciple of Pythagoras, and which survived into medieval times in the form of the doctrine of the four humours. When Eryximachus speaks of Asclepius as 'our forefather' he is speaking as a member of one of the medical guilds which took the name of 'sons of Asclepius' from the name of the patron-god of medicine.