After I give lectures — on almost any subject — I am often asked, "Do you believe in UFOs?." I'm always struck by how the question is phrased, the suggestion that this is a matter of belief and not evidence. I'm almost never asked, "How good is the evidence that UFOs are alien spaceships?"

The Demon-Haunted World: Science as a Candle in the Dark, Chapter 3 (p. 82)