You don't have to be a self-conscious sceptic to enjoy this superb book. To some, sceptics are killjoys who explain the weird noise in a haunted house as the puffing of an automatic air freshener rather than a ghost sneezing, or (in a recent Guardian piece by Daniel Dennett) just plain old-fashioned "loonies" (sorry, "moon-landing sceptics"). Richard Wilson takes scepticism a lot more seriously, for the simple reason that it can be a matter of life and death. More scepticism within the South African government towards Aids denialism, for example, could have prevented "one of the greatest man-made disasters of the modern era" (when that government "deliberately delayed the roll-out of antiretroviral drugs"). Scepticism is one of the great positive virtues we should all cultivate, not just a thorn in the side of woo.
Wilson starts the book with a scam he witnessed as a teenager (but which goes back to the Middle Ages and from which we get the expressions "buying a pig in a poke" and "let the cat out of the bag"). He was impressed that the "salesman had managed to fool the crowd completely, while speaking the literal truth", relying on haste and greed for a bargain to override the crowd's better judgement. This is hardly grand larceny of course, but no less instructive for being on a small scale. After all, we're more likely to fall victim to this kind of salesmanship than to the high-rolling Madoffs of this world.
One of the pleasures of this book is the real-world examples that get you hot under the collar (and misty eyed about trading standards and the Sale of Goods Act). Another is the serious intellectual argument against relativism. The glib catchphrase "it's all relative" is "an idea with troubling implications". "If truth is entirely subjective, then it's futile even discussing your point of view with people you disagree with. If we reject logic, then it's impossible to put together any kind of system for distinguishing good ideas from gibberish." There are many straightforward questions we can ask of any factual claim. "Is the evidence detailed and specific or vague and generalised? Does it come from multiple sources or just a handful? Is it internally coherent, or are there contradictions? Is it consistent with other well-supported facts? Are human sources named? If so, what are their credentials and what's their track record?"
Everyone can understand these principles, even if they can be hard work to follow through. "The antidotes to delusion are logic and evidence, preferably evidence from multiple sources" and Wilson himself sets a good example, with forty-nine pages of notes. Much of his source material is available on the web, which he rightly celebrates as enabling better access to a wider range of fact and opinion. Of course, such access could be counterproductive, especially if we switch off our sceptically tempered judgement.
Flexibility is key: when better ideas come along, we need to change. Science is one system that has proved spectacularly successful at revising itself, while religion has a pitiful record. The reason is simple: only religion makes a virtue of faith, of holding fast to a dogmatic core, which renders it intellectually brittle, and constantly in need of strapping delusions to hold it together. "Religion is, in a sense, the ultimate pig in a poke."
Given the overall good sense of the book, I was quite surprised to come across some isolated pockets of duff thinking. At one point Wilson says, "we have no rational way of knowing what the future holds", which seems odd after extolling the benefits of "inductive reasoning": if it's not rational to believe the sun will rise tomorrow, then all bets are off. Even in the context of our unpredictable personal lives, where he talks about having "irrational faith" in the future, I would rather think in terms of "rational hopes" (for example, planning for a rainy day by saving instead of buying lottery tickets).
I was also surprised by his perplexity at the continuity of self given the discontinuity of the materials of the brain (our cells are constantly being replaced). "Once we take the immortal soul out of the equation, even the idea of ourselves as individual beings whose existence endures steadily throughout one lifetime seems difficult to sustain..." Does it? Our thoughts are not tied to particular neurons but to the (complex) relationships between neurons, and these patterns surely survive the substitution of individual atoms and molecules. These are difficult subjects, and I could be the one who's off the mark here. Anyway, even if he is wrong on some things, I admire him for writing with clarity and transparency, for not obfuscating or making unwarranted appeals to authority.
He is right to emphasize that being a sceptic does not "necessarily mean believing in nothing" and this book will help dispel the caricature of a disengaged, cynical and generally negative person. Never before has humanity had so much access to so much learning, but along with that enhanced freedom comes the responsibility to exercise our sceptical muscles. We have the tools: the "basic principles of logic, consistency, evidence and 'inductive reasoning' are common to every human society" and are not the sole preserve of some imagined western intellectual elite. It's up to us to challenge faith, ideology, prejudice, ignorance, whatever stands in the way of getting at the truth. For Christians, "Doubting Thomas" was a failure, the person they should strive not to be. For Wilson, Thomas would make a fine "patron saint of sceptics", someone who is not afraid of asking awkward questions.