Professor of Logic

The joke that inspired this entire website.

A man is sitting on a train when another passenger sits down across from him. The second man says, "Excuse me, but I couldn't help noticing you're reading a philosophy textbook. Are you a professor?"

"Yes, I am."

"What do you teach?"

"Logic."

"What's logic?"

The professor thinks for a moment. "Let me give you an example. Do you have a dog?"

"Yes."

"Then logically, you probably have a backyard for the dog to run around in."

"I do."

"And if you have a backyard, logically you probably have a house."

"I do."

"And if you have a house, logically you're probably married."

"I am."

"And if you're married, logically you're probably heterosexual."

"I am! That's amazing!"

The professor nods. "That's logic."

Later, the man sees his friend and excitedly tells him about meeting a professor of logic. "What's logic?" his friend asks.

"Let me give you an example. Do you have a dog?"

"No."

"Then you're gay."

The joke works on multiple levels: it's a legitimate (if silly) demonstration of logical reasoning, followed by a complete failure to understand what logic actually is. Norm told it with such patience and precision that the punchline—which the audience sees coming—still lands perfectly.