Perhaps rooted in real events, conceivably rooted in real beliefs.

The story goes that Bertrand Russell (sometimes people say it was Feynman, I've heard both ways) was giving a public lecture about the cosmos, and a seemingly nice old woman stood up in the question period and said "This is all rather preposterous, Doctor Russell. All reasonable people know that the Earth is a disk balanced on the back of a giant turtle."

Russell, taken aback but game for a challenge, tried to talk this woman out of her craziness with Socratic pedagogy. "An interesting hypothesis, madame, but what might that turtle be standing on?"

The old lady immediately cut him off, "You can't fool us with logic games. It's turtles all the way down!"