Book 9
8.50
Protagoras, son of Artemon or, according to Apollodorus and Dinon in the fifth book of his History of Persia, of Maeandrius, was born at Abdera (so says Heraclides of Pontus in his treatise On Laws, and also that he made laws for Thurii) or, according to Eupolis in his Flatterers, at Teos; for the latter says: Inside we’ve got Protagoras of Teos. He and Prodicus of Ceos gave public readings for which fees were charged, and Plato in the Protagoras316 a. calls Prodicus deep-voiced. Protagoras studied under Democritus. The latterCf. Clem. Strom. vi. 32, and Suidas, s.v. Δημόκριτος. was nicknamed Wisdom, according to Favorinus in his Miscellaneous History.
8.51
Protagoras was the first to maintain that there are two sides to every question, opposed to each other, and he even argued in this fashion, being the first to do so. Furthermore he began a work thus: Man is the measure of all things, of things that are that they are, and of things that are not that they are not. He used to say that soul was nothing apart from the senses, as we learn from Plato in the Theaetetus,152 a sq. and that everything is true. In another work he began thus: As to the gods, I have no means of knowing either that they exist or that they do not exist. For many are the obstacles that impede knowledge, both the obscurity of the question and the shortness of human life.
8.52
For this introduction to his book the Athenians expelled him; and they burnt his works in the market-place, after sending round a herald to collect them from all who had copies in their possession.
