Anathem reads like Stephenson swallowed a copy of the Durants' The History of Philosophy and couldn't wait to regurgitate it in what he fondly hoped was an entertaining form. FAIL. Two thirds of the book is taken up with dialogue between avouts, who live cloistered lives in Concents separate from the outside world (extramuros), and this dialogue is largely about philosophers and their theories. I suppose this is fascinating if you enjoy reading this sort of thing, but to me it was every bit as bad as the mathematical formulae that infested so much of Cryptonomicon, and there was a lot more of it, obscured by jargon. The book begins as a mystery set in a concent, expands to a moderately funny travelogue as the protagonist and his companions travel through the extramuros, and winds up as a First Contact story mixed with a societal revolution. I'm willing to buy into the notion that Stephenson didn't think he could tell the last two-thirds of the novel without laying the philosophical groundwork in the first third, but I wish to God he'd put a lot of that bulshytt in footnotes.
After the Baroque Cycle, I had hoped Stephenson had gotten over this kind of expository bloviation, but apparently not. Anathem is a sad relapse into bad writing habits, and I can't recommend it anywhere near as enthusiastically as his previous novels.