Believing Bullshit: How Not to Get Sucked into an Intellectual Black Hole by Stephen Law Read Free Book Online

of something that is not saliva at all, but just looks and feels like it. We have Samantha rub her miraculous spit on a number of subjects with various medical conditions: cuts, skin complaints, and so on. This trial is “double-blind”: neither the subjects to whom the substances are applied nor Samantha know who are getting Samantha's saliva and who are getting something else. We then monitor the subjects to see if those with a certain sort of skin condition, cut, and so on recover more effectively than those who do not. If Samantha's spit really does have the miraculous power she claims, we should expect those who receive it to get better quicker than those who don't.
    Such a test might provide strong evidence that Samantha's spit does, indeed, have such extraordinary powers. However, suppose those who receive Samantha's saliva treatment fail to get better any quicker than those who don't. Surely this would provide us with a strong piece of scientific evidence that Samantha's claim is false. Suppose a variety of further tests are conducted, all of which produce a negative result. And suppose that we have (which, of course, we do) credible scientific evidence that people are highly prone to the power of suggestion (merely telling someone that something will make them better can be surprisingly effective—see Piling Up the Anecdotes ). Surely the reasonable conclusion to draw, now, would be that Samantha is mistaken, and that the testimony of her friends and relatives concerning the miraculous powers of her saliva is in large part a result of the power of suggestion.
    It's worth emphasizing that in the above example, science would not just have failed to find evidence that a certain supernatural power does exist. It would have established pretty conclusively that it doesn't exist. We would have not just an absence of evidence but evidence of absence. When supernatural claims are tested, and we get a negative result, true believers often insist that this “proves nothing”—we may not have found evidence for what they believe, but we haven't shown what they believe is false. In some cases, that's true. But “prove” is a slippery word (as we'll seelater in this chapter), and it may be that the tests have established beyond reasonable doubt that their belief is false.
    So science can pretty conclusively refute at least some claims of a supernatural nature. This is because such claims, if true, often have empirically observable consequences. They are, in this respect, no different to claims about other “hidden” phenomena, such as claims about tiny, unobservable particles, or about the distant past. Such claims may be about phenomena to which we don't have direct observational access. But that's not to say that they cannot be pretty conclusively refuted by the methods of science.
    Of course, it will always remain possible that Samantha's spit does, sometimes, have miraculously restorative powers. We might still be mistaken. But that's not to say we're not justified in supposing Samantha's claim is false. It's possible that my attic is inhabited by invisible space gerbils, that George Bush was a robot, and that the French are Martian imposters and the Eiffel Tower is a transmitter for secretly sending reports back to Mars. Any nutty belief about the world can always claim to be possibly true, for we can never prove beyond all possible doubt that it's false (as we'll see in “ But It Fits! ”). That's not to say we can't prove beyond reasonable doubt that it's false.
    Samantha and her miraculous spit was a hypothetical example. However, many claims of a supernatural nature have been scientifically investigated in some depth. Scientists have tested the claims of remote viewers, psychics, crystal healers, and so forth and others claiming to have some sort of supernatural ability. Such investigations have failed to provide good evidence that any of these abilities actually exist, and, in many cases, they have provided