The protagorean doctrine in the Theaetetus and its influence on the constitution of ancient skepticism

Abstract

This article examines the influence of the Protagorean doctrine, as expounded in the Theaetetus (following Plato’s account, and thereby not taking sides on the debate on whether it actually coincides with that of the historical Protagoras or not) in the shaping of the defence statement listing the ten modes to induce suspension of judgement, attributed to Aenesidemus and also exposed by both Diogenes Laertius and Sextus Empiricus. This indebtedness can also be noticed in Sextus’s reception of Aristotle and in his concern to address the criticism that, at that time, was probably aimed at, among others, Protagoras’s doctrine, as presented in the Theaetetus.