Plato (~428-~348 BC) - One of the greatest and most influential Greek
philosophers, he was a disciple of Socrates and the teacher of Aristotle.
Most of his works are written dialogues, many with Socrates as the main
character. Plato founded a school of philosophy known as the Academy.
Parmenides (360 BC) - A dialogue in which old Parmenides advises the
youthful Socrates to argue by the Zenonian method. This is one of Plato's
dialectical dialogues.