The crocodile sophisme is the best paradox I've ever read,and I got a whole book on mathematical,logical and optical illusions.
It goes something like this:
The Crocodile Dilemma is an unsolvable problem in logic. The premise states that a crocodile who has stolen a child promises the father that his son will be returned if and only if he can correctly predict whether or not the crocodile will return the child.
The transaction is logically smooth (but unpredictable) if the father guesses that the child will be returned, but a dilemma arises for the crocodile if he guesses that the child will not be returned. In the case that the crocodile decides to keep the child, he violates his terms: the father's prediction has been validated, and the child should be returned. However, in the case that the crocodile decides to give back the child, he still violates his terms, even if this decision is based on the previous result: the father's prediction has been falsified, and the child should not be returned. The question of what the crocodile should do is therefore paradoxical, and there is no justifiable solution.
I copied it from wiki,but I prefer the more storified version,where the father is really an Egyptian mother.
It goes something like this:
The Crocodile Dilemma is an unsolvable problem in logic. The premise states that a crocodile who has stolen a child promises the father that his son will be returned if and only if he can correctly predict whether or not the crocodile will return the child.
The transaction is logically smooth (but unpredictable) if the father guesses that the child will be returned, but a dilemma arises for the crocodile if he guesses that the child will not be returned. In the case that the crocodile decides to keep the child, he violates his terms: the father's prediction has been validated, and the child should be returned. However, in the case that the crocodile decides to give back the child, he still violates his terms, even if this decision is based on the previous result: the father's prediction has been falsified, and the child should not be returned. The question of what the crocodile should do is therefore paradoxical, and there is no justifiable solution.
I copied it from wiki,but I prefer the more storified version,where the father is really an Egyptian mother.