Plato's sage pupil (9)
I believe the answer is:
aristotle
(Other definitions for aristotle that I've seen before include "Greek philosopher, pupil of Plato, tutor of Alexander the Great" , "Ancient Athenian philosopher, pupil of Plato" , "Totaliser (anag) - ancient Greek" , "Thinking Greek" , "Totaliser for the great Greek philosopher of old" .)