Related Clues:

• Arrow paradox philosopher
• Geometry giant
• Uncomplaining sort
• Follower of the philosopher Epictetus
• Greek mathematician
• Philosopher in "The Clouds"
• Having a stiff upper lip
• Greek math whiz
• Not overly emotional
• Not moved much
• Not reacting to pain, say
• Hard to stir
• Epictetus, for one
• Early Greek Cynic
• Sarcastic sort