The Professor of Philosophy seems quite aware of what has happened. His previous little eye-flick of malice toward Phædrus has turned to a little eye-flick of fear. He seems to understand that within the present classroom situation, when the time comes, he can get exactly the same treatment he gave, and there will be no sympathy from any of the faces before him. He's thrown away his right to courtesy. There's no way to prevent retaliation now except to keep covered.

Ch. 29 - Zen and the Art of Motorcycle Maintenance (1974)