Darwin's Dangerous Idea
By Daniel C. Dennett

Dennett looks at Darwin's idea of evolution in a philosophical and logical framework instead of a biological one. The book points out that if we truly wish to know what we are in the scheme of things, Darwin is the place to start. You think you can grasp the magnitude of Darwin's leap and its implications for all human life and thought. And then Dennett shows you that you're only on the ground floor of a majestic skyscraper. Beautiful.