Arcesilaus of Pitane Simulacrum

The Life

Arcesilaus was born in Pitane, in Aeolis, around 316/315 BCE. He studied first with the mathematician Autolycus and later, in Athens, with the Peripatetic Theophrastus before entering the Academy under Crantor and Polemo. He became the sixth scholarch of the Academy in or about 268/264 BCE and held the office until his death in 241/240 BCE. He wrote nothing, or at least nothing that survived: the ancient reports describe a philosophy transmitted entirely through oral teaching and dialectical encounter.

The Thought

Arcesilaus turned the Academy in a direction that would have astonished its founder. Taking as his starting point the aporetic ending of the early Socratic dialogues and the acknowledged difficulty of Plato's theory of knowledge, he argued that human beings are not in possession of certain knowledge of anything. His method was entirely negative: he would invite an interlocutor to state a claim, and then, using the interlocutor's own concessions, construct the most powerful argument for the opposite. His target, in particular, was the Stoic doctrine of the cataleptic impression — the Stoic claim that there were certain perceptions so clear and so self-evidently true that assent to them was compelled. Arcesilaus argued that no such impression could be identified, because for every apparently compelling impression one could construct an indistinguishable false one.

From the impossibility of certain knowledge Arcesilaus drew the practical conclusion that the wise person should withhold assent — a stance called *epoché*, suspension of judgement — and act, insofar as action is necessary, on what seemed reasonable rather than what was claimed to be known.

The Legacy

The Sceptical turn under Arcesilaus dominated the Academy for nearly two centuries, through Carneades and his successors, until Antiochus of Ascalon broke with it in the first century BCE. It was a startling development — a Platonic Academy that denied certain knowledge — but it preserved something central to the Socratic inheritance: the willingness to follow the argument wherever it led, even against the founder's own doctrines. The ancient Pyrrhonian scepticism preserved by Sextus Empiricus, and the modern scepticism of Montaigne, Hume, and others, stands in a recognisable if indirect line of descent from Arcesilaus.