Paradox: The Barber’s Paradox

Objective

Students will grapple with The Barber's Paradox about a barber who may (or may not) shave himself.

The setup is: The barber is the person who shaves those, and only those, who do not shave themselves.

The question: Does the barber shave himself?

This sets up a contradiction:

1. The barber cannot shave himself, since barbers don't shave those who shave themselves.
2. But, if he doesn't shave himself, then he must shave himself, since barbers shave those who don't shave themselves!
3. But… barbers cannot shave themselves. 🤯