Many many years ago, I had a very good friend, someone I cared for deeply. She was intelligent, funny, very kind and helpful, almost always (it seemed) in a good mood. She did have one "flaw" however, although I use that word with compassion because it was the kind of flaw that is (alas) probably just part of human nature. The flaw was a serious lack of skeptical thinking. Why, I'm not certain. She was easily intelligent enough to have it. Perhaps it was her years as a member of the one true religion and acquisition of some position and responsibility in it that defeated her skepticism and left her a believer. (To be fair, I was in this religion for a number of years too, but it didn't defeat my natural skepticism and I escaped in time.)
So much for overtures, because I want to discuss a specific event between her and me. One fine day (all days in San Diego are fine days, until you get sick of it) she told me about her "theory" that the ancient Egyptians (and perhaps Mesopotamians) must have visited the Mayan and/or other Central American cultures. Reasoning? Both "ancient" cultures built large pyramids constructed of stone. That was it; she offered no other reasoning, no other evidence or logic, in the "theory's" support. She was probably as certain of it as she was of her religious truths.
If your mind is anything like mine's, and assuming you've heard this idea before, alarm bells were starting to clang in your head before you read this far. If you have a reasonable knowledge of history and geography (shame on you if you don't!) you can just sense that there is something(s) seriously wrong here, that the pieces of this puzzle surely can't hang together. To revive an old saying, "You can feel it in your bones."
That was precisely my experience, and I believe it is essential for our skeptical abilities to mature. Note that its main nutrient is knowledge, and not even very in-depth knowledge. When anyone tells us something that feels (to confirm, yes, I believe this usually starts as an act intuition) out of synch with our own ideas and knowledge, it can make us startle as though we'd been teleported to a different world or time. Of course, if your ideas and knowledge are incorrect, skepticism is pretty much in vain.
That's where it starts, I suggest, with that (often small) sense of dislocation, because it conflicts with at least something we know to be true. But if you end there, you would rightfully accused of just dismissing the person without argument. Furthermore, it would probably leave you with a funny feeling, as if you've failed yourself somehow. And you would be right here too. (Of course you can just make an agreeable grunt and change subject: as I think Shaw said, "Arguments are to be avoided. They are always vulgar and often persuasive.)
Furthermore, there is always a real possibility of you being wrong, or not having enough facts at hand. Or you can't summon all your defenses for the barrage of logical fallacies and cognitive biases about to assault you.
So I decided to file the issue away, to ruminate about it later when I was alone and could think clearly. When I did, the objections to her "theory" came swiftly and completely enough. I am not going to go over them (I am confident that you can find them yourselves quickly too).
So what happened to us, her historical speculations, and so forth? Between us nothing, for I knew better than to debate a firm believer in the one true religion -- I did say I cared very much for her, didn't I? Let sleeping cats sleep. But for me, it was an important triumph of my mind, a victory I have always carried with me, knowing I may need it any time. And don't doubt one thing: life has that much richer for it.
