The Platonist Academy in Antiquity

In the case of Plato, there's an enigmatic period known nowadays as the old Academy headed by Spusipus and then by Cenocrates. This was a succession of teachers at Athens who attached themselves to the Socrates of the Aporetic Dialogues. They questioned all doctrines, and doubted whether certainty might be achieved in any sphere of human knowledge. The term academic in antiquity would come to mean skeptical.