Like people even today, the ancients had to deal with verisimilitude: the appearance of truth. Something that appears true may indeed be true – or it may not be. Earth being motionless is a verisimilitude, an appearance. It seemed true. It still seems true. It would have taken extraordinary insight and courage to question publicly whether it is actually an illusion. With the tools at hand 2,300 years ago (none), how could anyone possibly turn such a longstanding belief on its head?