It's a peculiar film, in a lot of ways. On one hand, it's a film that teeters dangerously closely to the edge of sentimentality in its depiction of religious conviction, with Eli so convinced that he's doing the work of the Lord that he keeps going when most would give up. Yet on the other hand, it yanks back the comforting blanket of personal faith to expose the control and manipulation of people by religion that lies underneath. Eli tells Solara, his female travelling companion, that "after the war", Bibles were burned because many believed them to be the cause of the war. As far as social commentary goes, it's a little ham-fisted, but in a clumsy way, the film has highlighted the importance of books.
Religious books, encyclopaedias, text books and even novels all tell us something about the world in which we live. A heavy tome about chemistry and a dog-eared copy of a hard-boiled detective novel are alike in their ability to grant power to the reader. Throughout the ages, dictators have recognised both the power, and the threat, of the knowledge contained in books, which is why the pages of history are dotted with scorch marks and burnt edges. Of course, the much higher level of global literacy makes the availability of information so much more dangerous. If people can read, then nothing is stopping them learning about economics, philosophy, history, mathematics or, inevitably, religion.
This, in a way, is another of The Book of Eli's veiled warnings. Few people can read in this post-apocalyptic world, leaving men like Carnegie and Eli as the sole interpreters of the written word. Interpretations are often coloured by bias, and where Eli appreciates the spirituality of the Bible, Carnegie sees only a route to power, at the expense of the spirituality of those he seeks to oppress. It's essentially a microcosm of religion as a whole. Some people view the teachings of their chosen religion as guidelines on how to live a fulfilled, and happy, life. The rest use the teachings to instill fear and obedience into their followers. This is why I say that books contain information and knowledge, but not truth. Truth is far too subjective, and open to interpretation. There is nothing inherently wrong with the information - it is the way in which it is used which casts a ruddy glow or gloomy shadow across it.
I won't sport with your intelligence by discussing the "twist" ending, but sufficeth to say, the book is not all that it appears. I would have imagined that you guessed that already. In a lot of ways, Eli is a truly admirable character, devoted to his cause and possessed by the sort of inner fire that you often dream about finding within yourself, when you're clinging to a pole in an overcrowded train carriage on a wet Monday morning. My biggest problem is that I simply can't put enough faith into the teachings of the book he is trying to hard to protect.
Still, in this digital age, it's quite nice to see a film centered upon a book. After all, I can't quite picture a film in which one man would happily shoot another over a Kindle, can you?