Does the chair exist?

A lecture hall was packed with philosophy students on their first day of class.

Their grey-haired professor raised his hands above his head and the class began to fall quiet. In one swift movement, the professor grabbed his chair and slammed it onto his desk.

The professor turned around and etched a challenge on the whiteboard – this was to be their first graded assignment.
It read – “Prove to me this chair doesn’t exist”.

Given one hour to complete their essay, all of the students began with haste. Within 30 seconds, one student stood up and handed in his assignment in front of his bemused class.

Can you guess what the student wrote?
“What chair?”
This student received an A for his assignment.

When was the last time you or your team were encouraged to think outside the box?