Bob Price explained it this way:
The principle of analogy is so simple, so natural, that everyone uses it in daily life.
Imagine someone sitting down in front of the television after a long day at work. The first image he sees is that of a giant reptile squashing tall buildings. Is one’s first hunch, “Oh! The news channel!”? Probably not.
More likely one surmises the TV set had been left on the science fiction channel. Why? Because one’s world of contemporary experience does not include newscasts of giant dinosaurs wreaking havoc in modern cities, but one has seen monster movies in which such disasters are quite typical. Which analogy does the TV screen image fit?
How do we categorize a miracle claim from history? What’s it analogous to? Does it look like the plausible activities of ordinary people or does it look like legend? You can’t say for sure, of course, but which bin does this claim best fit into?
Did a winged horse fly Muhammad from Mecca to Jerusalem and back? Did Joseph Smith find golden plates with the help of the angel Moroni? Is the “Buddha Boy” able to meditate for months without food or water? Could Sathya Sai Baba raise people from the dead? Can faith healers cure illness that modern medicine can’t? Science has no analogy to these claims, but mythology and legend do.
Incredibly, I’ve heard Christians reject this principle and argue instead that an atheist must bring positive evidence against their claims. Don’t simply say that the Jesus miracles look like myth or legends, so we should classify them that way; no—that doesn’t count.
Of course, I have no direct evidence against this particular event. I have no direct evidence that Jesus didn’t raise Lazarus or that Merlin wasn’t a shape-shifting wizard or that Paul Bunyan didn’t exist or that George Washington didn’t fly around Mount Vernon with a jet pack. The plausibility test that we all use helps ensure that we don’t simply believe everything we hear or read. Well, all of us, I guess, except someone who’s eager to make exceptions to preserve a preconception.
Something can violate the Principle of Analogy only with substantial evidence. The claim “I can see through opaque objects” properly fit into the magical category until Wilhelm Röntgen demonstrated x-rays.
Until we have an analogy to a miracle story, it properly belongs in the magical category as well.
I believe that an orderly universe,
one indifferent to human preoccupations,
in which everything has an explanation
even if we still have a long way to go before we find it,
is a more beautiful, more wonderful place
than a universe tricked out with capricious, ad hoc magic.
— Richard Dawkins, Unweaving the Rainbow
(This is a modified version of a post that originally appeared 8/29/11.)