Final exam…

Legend has it that a certain college philosophy professor asked one question on his final exam.
He picked up a chair, put it on his desk and wrote on the board, “Using everything we have learned this semester, prove that this chair does not exist.”
The students dug deep and wrote like crazy for the whole exam period, some of them churning out thirty pages of heady philosophical debate and logic.
But only one student earned an A and he wrote for only a few seconds.
His paper read in full, “What chair?”

from Bits & Pieces by Jonco