Wrestling with Religion

In The Demon-Haunted World : Science as a Candle in the Dark (1997), Carl Sagan imagines that he has offered to show me a fire-breathing dragon in his garage, and, when I get there, I see only "a ladder, empty paint cans, and an old tricycle." He'd neglected, it seems, to mention that the dragon is invisible. This thought experiment imagines my proposing a series of ways to detect the dragon. They are good ideas, he imagines replying, but unfortunately won't work. Flour on the floor won't because dragons levitate, infrared won't because dragon fire is heatless, and spray paint won't because dragons are incorporeal. If Sagan insists on countering every test I propose with an evasive redefinition, it's clearly silly for him to then shift the burden of proof onto me and suggest that, since I can't prove the dragon is absent, it may very well be present. There's no practical difference between an undetectable dragon and no dragon at all. ...

Imagine that you and I are in the living room of an American suburban neighborhood and you are by a front window looking out, but I am not. You report that a neighbor is walking her dog. I may not look even up from my book. I believe you because dog walking is common on our cul-de-sac. Your word is all the evidence I need. Now, let's suppose you tell me she is walking a greyhound, which is far less common but happens. A family two blocks away owned a rescue greyhound last year, but it apparently died. They have a short life expectancy. I may lower my book to look, but, unless you are a terrible liar, I'll take your word for it even if the dog is out of sight by the time I reach the window. The event is interesting but ordinary. Now, suppose that you say that a cowboy is riding a pony down the street. I have seen riders in rodeos and on country roads but never in the neighborhood. I don’t doubt that a cowboy is possible, but he is far less ordinary than a dog-walker, so I ...