He seemed relaxed, in sharp contrast with the atmosphere in the room. His students were tense. They were somehow trying to grasp the answer that was infuriatingly out of reach. I stared hard around me. I asked myself.
Man is the animal that laughs.
Anyway, you can't tell by just looking at something. And so the students persisted and the professor pointed out the fallacies. I'd have to find the answer myself to be completely satisfied. Gradually, preoccupied with other things at the time, the question was forgotten. Thirty years later, a dream brought the question back to mind.