It was a normal night late in reading period. Jon was studying math, and he was so immersed that he would have had to stop and check to find out what day it was, or what the weather was like outside. By one a.m. his mind had started to go numb from an overdose of theorems and problem sets.
His concentration would not hold, so he decided to close up his books for the night. He gathered up his soap, towel, toothbrush, and water mug and wandered out of his room down the hall towards the bathroom to wash up.
In the hallway by the third-floor landing he came across Chris from down the hall, who had also just reached his saturation point in studying. After their evening's bout with formal learning both Jon and Chris just wanted to free associate. They stood by the stairwell talking about whatever popped into their minds. Jon started to tell about the math he had learned that night, but quickly got off the subject for fear that it was becoming an obsession.
Chris told about what he had just read for a Folklore course. He related one African folk tale and then explained how the people whose culture produced the tale did not believe in free will. The moral of the story he told was that people cannot defy their fates.
Chris looked Jon in the eye. "Nobody has free will, you know," he said.
"I do, at least," Jon replied. The notion of no free will was too much for Jon's mathematized brain, which wanted to keep at least some self-esteem.
"No, not even you have free will," Chris said. He was playing devil's advocate, but Jon still did not want to let him get away with it.
"I do have free will, Chris," Jon said, his voice rising.
"Prove it. You can't prove it," Chris asserted.
A fierce gleam rose in Jon's eyes and he gave a tight smile. He looked at Chris for a few seconds, and then in one quick motion he threw his mug two floors straight down the stairwell. With a loud pop it shattered on the ground floor. Several doors on that floor swung open and several overworked residents looked up at Jon and Chris.
"What was that?" one asked.
Jon said, "It was just a demonstration. I was giving Chris here a lesson on the limits of determinism. Don't worry, I'll clean it up." The ground floor residents went back into their rooms.
Chris looked at Jon with new respect.
"You really do have free will.