Possible Clues:

• A great thinker, tries a lot to be different
• Greek philosopher in the lyrics to Taylor Swift's "So High School"
• 'Metaphysica' writer
• Realist unsettled, but holding to philosopher
• Great Greek philosopher, pupil of Plato
• A knight rising to let out Alexander's mentor
• Great Greek philosopher of 4th century B.C.
• Peripatetic teacher from Plato's Academy
• Realist to upset philosopher
• Emerge having grasped everything to refute a philosopher