"A purely psychological explanation is ruled out... the discs show signs of intelligent guidance, by quasi-human pilots."

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It was all very well going on about pure logic and how the universe was ruled by logic and the harmony of numbers, but the plain fact of the matter was that the Disc was manifestly traversing space on the back of a giant turtle and the gods had a habit of going round to atheists' houses and smashing their windows.

— Terry Pratchett