Paradox: Crocodile Dilemma
Students will grapple with The Crocodile Dilemma, a paradox from Ancient Greece in which a set of parents negotiate with a tricky crocodile who has stolen their baby.
Here's the setup:
A crocodile has stolen a child. He will return the child if (and only if) the parents correctly predict what he'll do next (either return the child or keep the child).
The first situation is pretty simple, but the second one is a mind boggler.
- If the parents guess that he'll return the child:
- If he was indeed going to return the child, then they predicted correctly and he'll return it.
- If he wasn't going to, then they predicted incorrectly and he keeps the child.
- If they guess he was going to keep the child:
- If he was indeed going to keep the child, they guessed correctly and he returns the child. But… then they actually guessed incorrectly and he'll have to keep the child. But then that's what they predicted and he has to return the child… and so on. PARADOX!
- If he wasn't going to keep the child, then they guessed wrong, so he has to keep the child. BUT that's what they predicted in the first place so now they're right and he has to return the child, but he wasn't going to do that originally so now he has to keep the child… PARADOX!
Read more about the crocodile dilemma at Wikipedia.