The issue becomes further complicated when we're biased ahead of time to accept (or reject) the source itself. A study (here) by Charles Lord and Cheryl Taylor, of Texas Christian University, indicates that people are more likely to accept as correct false statements if they're told that the false statement came from someone whose political or religious stance they share, and conversely, to think true statements are false if they're told that the true statement came from a source in the opposite ideological camp. Another study (here), by Emily Pronin, Daniel Yin, and Lee Ross of Stanford University, further indicates that just about everyone believes him/herself to be unbiased as compared to others; and worse still, a study by David Dunning (here) suggests that we are likely to rate ourselves as "above average" in knowledge, even in realms in which we score in the bottom quartile.
In other words, none of us is aware of how unperceptive, biased, and ignorant we actually are.
So, the salient question becomes: given that this is the case, how do we know what is true or false?
Well, in the absolute sense, we can't. We're trapped inside our own skulls, and certainty about anything is probably unrealistic. Science helps, because it establishes a baseline for validity, along with a reliance on hard data. But even science doesn't solve the problem entirely; as James Burke, one of the finest thinkers I know of, said, in his wonderful documentary series The Day the Universe Changed, "Even when you get the raw data, the situation doesn't improve. Because it isn't raw data. It's what you expected to find. You'd designed your equipment based on what you already thought was going to happen, so what your equipment is good at doing is finding the kind of data you reckoned you were going to find."
Still, the situation isn't as dire as all that, or we'd be in doubt about everything. There are ways we can detect specious thinking, and an assortment of red flags that will alert us to bias, slant, and outright lies. Let's look at one fairly simple example, which appeared in the rather goofy online magazine Who Forted? (although let's not dismiss it just because of the source; see paragraph 2).
Entitled "Bad Vibes: Can Dealing With Evil Spirits Kill You?", this article makes the claim that delving too deeply into the occult puts you in touch with "forces" that can have negative effects on your health. "(W)hat about those few people who make it a career to deliver the mortal souls of sinners from the grip of evil?" the author, Greg Newkirk, asks. "What of exorcists, demonologists, and ghost hunters with a flair for the dramatic and a reality show audience? Is there a risk in placing yourself between a negative spirit and it’s [sic] prey? Surely the religious will believe that it’s your own soul at stake, but do the scars of spiritual warfare have a physical manifestation? What I’m asking essentially amounts to one question: Can the pursuit of evil spirits affect your heath?"
Newkirk then goes on to describe the various ways in which evil spirits could cause you harm, including (to his credit) the practitioner simply experiencing continuous stress, fear, and negative emotions -- i.e., the effect could be real even if the spirits themselves aren't. (This, then, might qualify as a sort of nocebo effect -- a documented phenomenon in which a person who believes himself to be in harm's way from supernatural causes actually experiences negative health effects.)
The most interesting part, to me, is when Newkirk begins to list off various psychic researchers, exorcists, black magicians, and so on, gives a brief curriculum vitae for each, and describes how and at what age each died. If you want the complete stories, check out the link, but here's a list of names, ages, and causes of death:
- Malachi Martin, 78, brain hemorrhage
- Ed Warren, 79, cause not listed (but was chronically ill during the last five years of his life)
- Lou Gentile, early 40s, cancer
- George Lutz, 59, cancer
- Tom Robertson, still alive (from his photograph, he appears to be 60-ish), has prostate cancer
- Ryan Buell, still alive (age 30), has pancreatic cancer
1) It's short. Beware of small sample sizes. Given a small enough sample size, you can find just about any sort of statistically unlikely pattern you'd like. (Sort of like if you rolled a die four times in a row, and got four sixes -- and decided that the chance of rolling sixes on a fair die was 100%.)
2) Given that the writer already had decided that working with evil spirits is dangerous, it's pretty likely he'd have selected examples that supported the conclusion he already had, and ignored ones that didn't. This kind of cherry-picking of data isn't always this obvious -- unfortunately.
3) Even despite #2, this was the best he could do? The first two men listed actually lived longer than the average American (US male average life expectancy currently stands at 75.6 years). A third, Tom Robertson, is still alive, and has a form of cancer that is often treatable. A fourth, George Lutz, died young of cancer -- but one of two photographs of Lutz in the article shows him sitting with a cigarette in his hand, in front of a full ashtray!
My point here is that there's a middle ground between accepting a source whole-cloth or rejecting it out of hand. There's no substitute for taking a cautious look at the argument presented, asking yourself some pointed questions about bias and slant (especially, given the Lord and Taylor study, if the source is one you habitually agree or disagree with!), and engaging your brain, before deciding one way or the other. And, if there isn't enough information to decide, there's nothing wrong with simply holding a judgment in abeyance for a while -- indefinitely, if need be.
A wonderful take on the whole idea of how to analyze claims is the chapter entitled "The Fine Art of Baloney Detection" in Carl Sagan's wonderful book The Demon-Haunted World: Science as a Candle in the Dark (which, in my opinion, should be required reading in every high school science curriculum in the world). Check it out, while you're taking a break from expelling evil spirits. It'll be good for your health.