Man is the measure of all things, of things that are that they are, and of things that are not that they are not.
ProtagorasThere are intelligible principles inherent in the matter of every phenomenon; because matter is essentially the sum of all the seemings that it has for any and all persons.
ProtagorasNo intelligent man believes that anybody ever willingly errs or willingly does base and evil deeds; they are well aware that all who do base and evil things do them unwillingly.
ProtagorasEveryone, including the Athenians [...] are right to accept advice from anyone, since it is incumbent on everyone to share in that sort of excellence, or else there can be no city at all.
Protagoras