Abstract: Arcesilaus of Pitane succeeded Crates as head of the Academy in the mid-270s, and is credited with instigating the era of the ‘sceptical’ Academy. Dillon shows that this radical change of direction was in fact inspired by Arcesilaus’ desire to return to the original spirit and methods of Plato's philosophy. Faced with the challenge of Zeno of Citium's nascent Stoicism, which in many ways was a logical development and intellectual heir of Platonism, Arcesilaus revived the dialectic of Plato's ‘Socratic’ dialogues and attacked the Stoic belief in the certainty of sense perception. Arcesilaus thus reinvigorated the sceptical and aporetic strand of his Socratic–Platonic heritage, as represented in a work like the Theaetetus, while eschewing the Timaeus-inspired cosmological speculation that had characterized the preceding 70 years.

Keywords: aporetic, Arcesilaus, dialectic, Scepticism, Socratic dialogues, Stoicism, Zeno of Citium,