Wordology, Crocodility

I love the way that word rolls off the tongue. Crocodility is an ancient word for fallacious reasoning

See if you can follow this paradox. A crocodile snatches a young boy from a riverbank. His mother pleads with the crocodile to return him, to which the crocodile replies that he will only return the boy safely if the mother can guess correctly whether or not he will return the boy.

There is no problem if the mother guesses that the crocodile will return him. If she is right, he is returned; if she is wrong, the crocodile keeps him. If she answers that the crocodile will not return him, however, we end up with a paradox: if she is right and the crocodile never intended to return her child, then the crocodile has to return him, but in doing so breaks his word and contradicts the mother’s answer. On the other hand, if she is wrong and the crocodile actually did intend to return the boy, the crocodile must then keep him even though he intended not to, thereby also breaking his word.

The paradox is such an enduring logic problem that in the Middle Ages the word 'crocodilite' came to be used to refer to any similarly brain-twisting dilemma where you admit something that is later used against you.