This book is extremely good and also important. It's a treatise on metaphysics as well as a compelling story which the author says is autobiographical. It's exactly right about the scientific method, and the way we go about discovering truth as a society and as individuals. The analogy of working on motorcycles is a good one. In my life it's been programming computers and figuring out how to get industrial machinery to work, but the same process works for all of the above.
The thing I find most excellent in this book is that it points out the step where the mystery comes in, i.e. coming up with new hypotheses, the long sought "aha" that comes when you're working on a hard problem. Science has no method for how you get that. You just play with the problem, turn it over in your mind, try things, strive to understand, and then the answer sometimes appears in your head. It's a complete mystery. There are stories in the history of science, about Kekule who figured out the ring structure of Benzene from a dream about a snake swallowing its tail, about Einstein at age 13 picturing what it would be like to ride the crest of a light wave, and on and on. This book showed me that buried in the heart of science is something generative and alive that defies scientific explanation, simply because it's outside the system.
"The truth knocks on your door, and you say 'Go away! I'm looking for the truth!' so it goes away." That's such an exact description of how our preconceived ideas often keep us from finding the truth. (The truth in this context is completely knowable once we've found it. I mean if the motorcycle runs afterwards, then we've solved the problem. That's why I love applied science and engineering.)
The other great idea that I use all the time from this book is that the very cutting edge, the place where the tire tread hits the pavement, is always messy and confusing and just a place of floundering around in uncertainty. He makes the analogy of a train, with all the cars full of facts that we know, and the engine, where new track is being laid, is not contained in any of the cars. It's always murky up there, and never neat and well-defined. So that unpleasant feeling of uncertainty, of confusion, of floundering around, it's the VERY THING that we should cultivate in order to discover the truth. I tell myself that when I'm in that situation, that I should revel in this feeling instead of dreading it. (And, in fact, I mostly get paid because I can stick through that feeling to the payoff, the "aha" part. The most important thing I learned in college is that something utterly confusing and befuddling can come clear if I will invest the effort to play around with it and figure it out. So I get to do that all the time now. =))
What I have found in the years of figuring out why programs or machines don't work, and fixing them, is that really very little in life and the universe is well-understood. We have this large mental construct of scientific understanding, and it's indeed impressive. We can cure typhoid now and build bridges that stay up (conscious irony). But even in the areas that we would like to think are very well known, and neat and clear, there is so much that isn't understood. Otherwise, why would these questions come up continually? Why doesn't this program work? Why is my pulper feed system not working the way we expected? Why did my motorcycle engine run so badly in the mountains? What made this bridge suddenly collapse during rush hour?
This book explores all of those ideas and sheds a lot of light on them. I understand the universe far better because of having read this book. That's why I gave it 5 stars, a rating I reserve for books that changed who I am or how I see the world.