God Emperor of Dune is a thought-provoking book. It is certainly the most philosphical so far, and portrays an implausible though fascinating picture of humanity in which deliberate oppression manipulates society. It is about the use of power, the danger of seeking absolute truth, and the importance of rulers retaining compassion for humanity and individuals. I went through the book quickly and could not put it down, mostly because I was fascinated by Leto II--an extremely complex character which I have come to think of as Herbert's idea of the mind of evolution itself, though with some traces of humanity. The dialogue is also fascinating. When I finished it, I felt like I had read a study of power in all its forms, with a plot thrown in as an afterthought, so I could't rate it very highly as a novel.