Peter Godfrey-Smith's Other Minds. It's one of the more beautiful science books I've ever read. Some passages remind me almost of Lem's Solaris, descriptions of nearly intractable phenomena, beings that generate patterns so beautiful and so apparently purposeless that it's hard to see them as anything but complexity for complexity's sake. But -- nonfiction, animals that exist here, cephalopods rather than alien life-forms. Godfrey-Smith conveys the sense of wonder exquisitely well. (And I read it shortly after I started viewing most nonhuman animals as moral patients, so... metonymy.)