"If you spend your life looking in vain for the Loch Ness Monster, stalking the lake with a camera, sounding it with sonar, and sending submersibles into its depths, and yet still find nothing, what is the more sensible view: to conclude provisionally that the monster simply isn’t there, or to throw up your hands and say, “It might be there; I’m not sure”? Most people would give the first response—unless they’re talking about God."