`I refuse to prove that I exist,’ says Page, `for proof denies faith, and without faith I am nothing.’

`But,’ says Man, `The Babel fish is a dead giveaway, isn’t it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don’t. QED.’

`Oh dear,’ says Page, `I hadn’t thought of that,’ and promptly disappears in a puff of logic.