"What was the Sherlock Holmes principle? 'Once you have discounted the impossible, then whatever remains, however improbable, must be the truth.'" "I reject that entirely," said Dirk, sharply. "The impossible often has a kind of integrity to it which the merely improbable lacks. How often have you been presented with an apparently rational explanation of something which works in all respects other than one, which is just that it is hopelessly improbable? Your instinct is to say, 'Yes, but he or she simply wouldn't do that.'" "Well, it happened to me today, in fact," replied Kate. "Ah, yes," said Dirk, slapping the table and making the glasses jump, "your girl in the wheelchair -- a perfect example. The idea that she is somehow receiving yesterday's stock market prices apparently out of thin air is merely impossible, and therefore must be the case, because the idea that she is maintaining an immensely complex and laborious hoax of no benefit to herself is hopelessly improbable. The first idea merely supposes that there is something we don't know about, and God knows there are enough of those. The second, however, runs contrary to something fundamental and human which we do know about. We should therefore be very suspicious of it and all its specious rationality."