I debated between 3 and 4 stars, so probably 3.5. I liked it a lot, but the first several chapters sometimes got tedious with the neverending lists of ways people ignore science. And I wondered who he was trying to convince. I should think most of the people who would read this book already understand that for the most part. Later chapters got better, although I felt he occasionally wandered off topic. In a way, that's good. His writing style is almost conversational (unless he's listing problems). I wondered if that's they way he lectured. Maybe that's why he was such a popular teacher.