Acatalepsy (from the Greek α̉-, privative, and καταλαμβάνειν, to seize), in philosophy, is incomprehensibleness, or the impossibility of comprehending or conceiving a thing.[1] The Pyrrhonians attempted to show, while Academic skeptics of the Platonic Academy asserted an absolute acatalepsia; all human science or knowledge, according to them, went no further than to appearances and verisimilitude.[1] It is the antithesis of the Stoic doctrine of catalepsy or Apprehension.[2] According to the Stoics, catalepsy was true perception, but to the Skeptics, all perceptions were acataleptic, i.e. bore no conformity to the objects perceived, or, if they did bear any conformity, it could never be known.[2]