See if this passage from early on in Anathem—and page 47 counts as very early—sounds familiar:

"Fid Halak, what is the origin of the Doxan Iconography?"

"A Praxic Age moving picture serial. An adventure drama about a military spaceship sent to a remote part of the galaxy to prevent hostile aliens from establishing hegemony, and marooned when their hyperdrive is damaged in an ambush. The captain of the ship was passionate, a hothead. His second-in-command was Dox, a theorician, brilliant, but unemotional and cold." (p. 47)

No-one could ever accuse Neal Stephenson of thinking small. Having progressed from technothrillers to cyberpunk to post-cyberpunk he then reimagined the twentieth century at some length with Crytonomicom. He then did the same for the Enlightenment, at even greater length, with the three volume Baroque Cycle. Anathem attempts something similar for the whole of Western civilisation, from Ancient Greece to Star Trek and beyond, in a mere 935 pages.

Whilst his recent novels have skirted around the border of science fiction Anathem is a full-blood SF novel and so requires a much more radical reimagining of our history. In my Advance Reader Copy, Stephenson signals as much with his introductory Note to the Reader, the first sentence of which is, "If you are accustomed to reading works of speculative fiction and enjoy puzzling things out on your own, skip this" (p. xv). If you do read on, you are rewarded with a timeline for Arbre, his imaginary world; a pronunciation guide for Orth, one of its languages; and a few words on measurement and biology before eventually reaching the narrative. Similarly, buttressing the story at the other end of the book is a twenty page glossary which tells you what "fid" or, indeed, "Anathem" means. (Stephenson’s faith in the SF reader notwithstanding, you will probably find yourself referring to this glossary a lot.) More detailed dictionary definitions of these terms—and some that don’t appear in the glossary—are also interspersed between the chapters.

This is the first time Stephenson has set a novel elsewhere than Earth and he clearly isn’t going to take anything for granted. Authorial fiat is not good enough. At the same time, at first you wonder why he set the novel elsewhere than Earth. Here is another quote:

Protas, the greatest fid of Thelenes, had climbed to the top of a mountain near Ethras and looked down upon the plain that nourished the city-state and observed the shadows of the clouds, and compared their shapes. (p. 84)

Just as Dox is Spock, so Protas is Plato (and Thelenes is Socrates), and what follows is a rewriting of the allegory of the cave. It goes without saying that it is a considerable act of chutzpah to rewrite Plato. Such pieces of historical appropriation recur again and again and risk turning the novel into a parlour game. In Stephenson’s own words Anathem is "a fictional framework for exploring ideas that have sprung from the minds of great thinkers of Earth’s past and present" (p. xiii). That’s fine as far as it goes, but it doesn’t go very far. It doesn’t explain direct cultural transposition, such as the Star Trek example above, nor headscratchingly jokey entries in the glossary such as:

Bulshytt: Speech (typically but not necessarily commercial or political) that employs euphemism, convenient vagueness, numbing repetition, and other such rhetorical subterfuges to create the impression that something has been said. (p. 893)

The cumulative impression is of a work that is two parts hubris to one part taking the piss. It is an impression that sticks, and even grows, until Stephenson drops a bombshell about two thirds of the way through Anathem. When he does actually explain why his world is so similar to ours it is both a shock and totally consistent with everything that has gone before it.

I've just devoted the first six hundred words of this review to the background of the novel without saying anything about what actually happens in it. This is because Anathem is primarily a work of world-building, and world-building on a massive scale, the clomping foot of nerdism taken to such an extreme that the criticism implied by M. John Harrison's phrase no longer registers. Still, it would be remiss to say nothing of the story that Stephenson uses this extraordinary construction to tell.

Erasmus is a young avout in the Concent of Saunt Edhar. Roughly speaking, this means he is a young scholar in a secular monastery devoted to the natural sciences. However, in Orth the word "Saecular" actually means "pertaining to the non-mathic world" (p. 906) whereas the Concent is part of the mathic world. Similarly, "Saunt" is a bit like saint but could be applied equally to Augustine or Einstein. Confused? Stephenson helpfully gives us a leisurely two hundred pages or so to immerse ourselves fully in this complex setting before eventually giving us a sniff of the plot. This absorbing early section of the novel resembles a science fiction version of Umberto Eco’s superb The Name of the Rose (1980) and it is a shame when it is time for Erasmas to leave the Concent.

The split into the Saecular and mathic worlds occurred over three and a half thousand years ago following the Terrible Events, a cataclysmic period in the history of Arbre. Whilst life in the Saecular world rises and falls with the churning of civilisation, life in the Concents—segregated from it—remains relatively constant. The avout are gatekeepers of knowledge and this arrangement both preserves their power and insulates the Saecular world from it. They can only emerge from their Concents for ten days every one, ten, hundred or thousand years, depending on their order. The exception is in times of crisis and it is for this reason that Erasmas and his comrades are summoned.

You might think that, after the gentle pace of the dip-your-toes-in-the-water opening, things would accelerate at this point; the world is in danger after all. You'd probably only think this if you couldn't feel the huge wodge of pages between the thumb and forefinger of your right hand. Erasmus makes a lazy peregrination of (literally) half the globe over the course of several hundred pages before arriving at his destination. The reason for this unrushed and slightly infuriating pace is quite simply that Stephenson has so much to tell the reader.

There has always been a strong pedagogic element to Stephenson's work; not for nothing is The Diamond Age subtitled A Young Lady’s Illustrated Primer. This book takes it to new levels. Here we have not just his infamous digressions—fascinating as always—but a narrative that is predominantly told in formal and semi-formal dialogue after the model of the ancient Greeks. Even after the novel is finished, even after the glossary, we are presented with three "calca," lessons in mathematics and philosophy for the reader that are only tangentially related to the story. All this, coupled with the boarding school atmosphere of the Concent, the adolescent voice of the protagonist, and the birds and bees approach to relationships, gives Anathem something of the air of a Young Adult novel. In fact, with its longeurs and constant debate, it occasionally resembles an unholy hybrid of The Republic and Harry Potter and the Half-Blood Prince, and it can be every bit as tediously wearing as that sounds. As Stephenson signals from the outset, nothing is left unexplained.

Anathem may be a bildungsroman with teenage overtones but Stephenson’s sights are clearly set beyond the YA market. He gives the impression of a Geek Philosopher King who has set out to write a fictional version of one of those massive, iconic works of popular non-fiction such as Guns, Germs and Steel or Gödel, Escher, Bach and he has done an astonishingly good job of realising this ambition. The novel does have a tendency to get bogged down in detail and there are intermittent bouts of tone deafness on Stephenson's part—both issues also present in his earlier work—but this doesn't detract from the impact of his achievement. Since Anathem writes its own rulebook to be judged by, it has succeeded in making itself almost entirely critic-proof anyway.

When advance copies of the novel started doing the rounds one well-respected critic was heard to observe that this could be the book that broke the cult of Stephenson. I'm not sure why, since Anathem is Stephenson to the power of Stephenson and I expect it to be warmly received by his ample fan base. For the fids of Saunt Stephenson this book will be everything they could have hoped for. He even takes them into space for the first time! For everyone else this monumental book is worth reading just because, like Everest, it is there. Anathem is a unique, impressive but fairly mad novel: one part hubris to one part taking the piss to one part gnarly geek awesomeness.

Martin Lewis lives in East London. His reviews have appeared in venues including Vector, SF Site, and The New York Review of Science Fiction.