Up to Arcesilaus, the Platonic Academy accepted the principle of finding a general unity in all things, by the aid of which a principle of certainty might be found [REF].
The doctrines of Arcesilaus, which must be gathered from the writings of others,[REF] represent an attack on the Stoic phantasia kataleptike (Criterion) and are based on the skepticism which was latent in the later writings of Plato [REF].