He begins the book with three personal stories: a guy who sponsors research on belief after a supernatural experience or hallucination (depending on your point of view), NIH director Francis Collins' conversion and exploration of faith and science, and Shermer's own conversion and deconversion from evangelical Christianity. He references the people and books that influenced him during that time of his life in great detail. His own deconversion included a period of Ayn Rand fandom and evangelism for it, sad to say. I have to wonder if he had a harder time giving up authoritarianism than he did belief in a supernatural, because it sounds like he was a true fanboy. At this point in his life he hadn't yet become a big fan of the scientific method (or else he would have been persuaded more by evidence than by teachers and authors).
Fortunately the book does finally get to the sciency stuff I bought it for. His main thesis is that people develop a belief first and then find reasons to support it, and he ranges over a lot of territory developing it. The most interesting thing for me was the phenomenon of sensing the presence of another person (usually) when nobody is there. It happened to Shermer on an ultramarathon bike ride. It has happened to other extreme athletes, especially mountain climbers. This may come as a surprise to some Christians, but the brain is part of the body, and when the body is under extreme stress, that includes the brain!
Pattern-seeking is another biggie, especially with the point that a false positive pattern is generally less dangerous than a false negative. His example is a rustle in the grass on the African savannah. Our ancestors are the survivors who assumed the rustle came from a snake or other predator. The dead ends on the evolutionary tree are the ones who thought "m'eh it's just the wind" when it was actually a snake. This is Pascal's Wager!
Another point that's interesting: the ability to find connections between things (pattern-seeking) is related to creativity, which explains why so many brilliant and creative people have fallen for stupid shit like UFOs and "alternative" medicine. The same person who might make a breakthrough in science because he saw a connection nobody else noticed isn't likely to filter out the ones that aren't really there, i.e. false positives. Psychosis is the complete inability to filter out false patterns.
There's a section on political beliefs, which is pretty interesting. There have been studies done on political belief and apparently (hold onto your hats!) people are very reluctant to give up their political leanings! YES!
His libertarianism doesn't really sound like Ron Paul libertarianism, though. He believes in a flat tax, and Ron Paul wants to have no tax at all, and even abolish the IRS. Some of Shermer's other views are really very moderate also. He's much more nuanced than he gives himself credit for, but there's no word for "practical libertarianism." Of course, since I kind of like the guy I may be giving him a pass in order to keep from changing my mind about him!
So... in the end his thesis that people come to their belief first and then find ways to justify it runs through the book but so do other ideas. He lists the typical biases that a lot of us probably already know about, like confirmation bias. These aren't dealt with in depth, though. I wish they were and there was less about libertarianism!
The last section of the book is a long discussion of the development of astronomy as a science, and the scientific method in general. As we should know (if we had the kind of education we ought to have had), the scientific method includes safeguards against natural biases of the scientists doing the experiments, and of the subjects, if they're human. He states that his thesis is that people decide what to believe and then rationalize them, but I think the book makes sense as a study of why the scientific method is the best way to arrive at a true result.
The best take-aways:
- People experience mysterious "others" during periods of stress
- The human brain seeks patterns because of evolution
- The human brain seeks an agent because of evolution
- People with an ability to make more connections than others are "creative" but also prone to conspiracy theories, mental illness, and just plain mistakes
- We are prone to fallacies that protect our beliefs
- The scientific method is designed to mitigate against the human brain's faults