During one of a professer's routine classes, he decided to raise a controversial subject:
He stood in front of his class and said: "Can anyone hear God? Can anyone see God? Can anyone smell God?" After a long pause, the professor concluded: "Because none of you can hear, see, or smell God, I conclude that there is no God."
Not to be outdone, one particularly potent student stood up. "May I address the class directly?" he asked.
"Yes, you may," the professor replied.
The student went to the front of the class and began: "Can anyone hear the professor's brain? Can anyone see the professor's brain? Can anyone smell the professor's brain?" After a particularly uneasy and long pause, the student finished: "Because none of you can hear, see, or smell the professor's brain, I conclude that the professor has no brain."