Recently, Bill Maher did a bit on Real Time about what he called “smart stupid people,” those who had advanced degrees but still believed bizarre, irrational ideas. His main example was the neurosurgeon who wrote about a visit to Heaven; but he also mentioned Sir Arthur Conan Doyle’s belief that the Cottingley Fairies were real, and how the guy who said fetuses masturbate in the womb was actually a gynecologist. Anyone who wanted to throw this back at Maher could mention how he spoke out against the germ theory of disease at one point, although I think he’s since become more rational on this point. Still, he seems to have an attachment to the idea that just about every ailment has something to do with diet; I’m not denying that diet has SOME effect, but he’s over the top about it. Similarly, I was a fan of Penn and Teller’s show Bullshit!, which was all about exposing hoaxes, but they had episodes claiming that we don’t have enough data to prove global warming and that nobody should have to pay taxes. I’ve also noticed how some people who are totally opposed to religion still have a religious sort of fervor for other ideas with no scientific support. Take communism or the gods being aliens, for instance.
Mind you, there is somewhat of a problem with dismissing other people’s beliefs as stupid or irrational, because often it simply comes across as saying “this person doesn’t believe the same things I do.” There’s obviously some bias involved, is what I’m saying. That said, I feel that an irrational belief is one that isn’t based on observable evidence, which doesn’t necessarily make it wrong. I’d say religion isn’t rational, as it’s based on faith, but that doesn’t mean I think every religious person is stupid.
Do all humans have the need to believe irrational things? I’ve certainly seen it proposed that all people have a spiritual side, even if they aren’t religious, but I’m not buying it. I just think rejecting one concept on the basis that it isn’t rational or scientific doesn’t mean you aren’t going to be susceptible to other such concepts. There’s also the question of how much we can trust our own observations anyway, but that’s getting into metaphysical territory.
As for people having visions of Heaven, I tend to think that, if you’re constantly told that the afterlife is going to involve clouds, pearly gates, and heading toward a light, that’s what your subconscious mind is going to produce. Not to mention that some of these images are so generic that you’re probably likely to see them even if you HAVEN’T heard of Heaven. But hey, if you can turn a hallucination into a best-selling book, more power to you.