Arcesilaus (c.316–c.240 BC)

Arcesilaus of Pitane came to Athens as a young man, and was seduced by Platonic philosophy. Around 265 he became head of the Academy. He turned the school in a sceptical direction, urging that Plato himself had been of a sceptical bent. He revived the Socratic practice of dialectical argument, in which he displayed remarkable logical skill and honeyed oratorical talent. His dialectical prowess led him to ‘suspend judgment about everything’; but the main target of his arguments was Stoicism, and in particular Stoic epistemology, which he claimed to reduce to incoherence. Recognizing that a sceptic must live and act, he introduced the notion of ‘the reasonable’ as a criterion of sceptical action.