There's a bookstore/coffeeshop I used to go to where I once heard another customer expound in an initially impressive and interesting manner that started to sound like BS after a while. I bought this book at that store and had the same experience reading it. Initially, it's informative and entertaining in the style of science books I usually enjoy, but after a while the author just sounded like the coffee shop arguer who loves to hold forth and after a while you can't believe anything he says. After some passages of there-are-some-other-theories-but-I-just-don't-buy-it, and self contractory grand statements like all those authoritarian conquerors really thought they were doing good, and later, all those authoritarian conquerors, they lied, I started wondering if this guy is for real, checked wikipedia and saw despite the celebrity endorsements (thanks, Obama), there are a lot of academic criticisms, and that was enough for me. As with the coffee shop arguer, I just stopped paying attention and abandoned the book after a few chapters.