David Deutsch covers a lot of ground in this book. From fundamental mathematics, to quantum physics, to philosophy and creativity, Deutsch applies a unique theory on all knowledge as the search for explanations. He’s kind of reaching, a lot of the time. It’s a basic error to start an investigation with a solution already in mind, as the result tends to be something between confirmation bias and complete blindness. For the places Deutsch’s theory works, it works really well: his explanation of quantum physics was one of the most interesting and “graspable” that I’ve read. However, he loses the thread when he starts to discuss the function of beauty. Overall, a really interesting read, but less revalatory than I think the author wanted.