In the twentieth century, all the nightmare-novels of the future imagined books would be burned. In the twenty-first century, our dystopias imagine a world where books are forgotten. To pluck just one, Gary Steynghart's novel Super Sad True Love Story describes a world where everybody is obsessed with their electronic Apparat -- an even more omnivorous iPhone with a flickering stream of shopping and reality shows and porn -- and have somehow come to believe that the few remaining unread paper books let off a rank smell. The book on the book, it suggests, is closing.

I have been thinking about this because I recently moved flats, which for me meant boxing and heaving several Everests of books, accumulated obsessively since I was a kid. Ask me to throw away a book, and I begin shaking like Meryl Streep in Sophie's Choice and insist that I just couldn't bear to part company with it, no matter how unlikely it is I will ever read (say) a 1000-page biography of little-known Portuguese dictator Antonio Salazar. As I stacked my books high, and watched my friends get buried in landslides of novels or avalanches of polemics, it struck me that this scene might be incomprehensible a generation from now. Yes, a few specialists still haul their vinyl collections from house to house, but the rest of us have migrated happily to MP3s, and regard them as slightly odd. Does it matter? What was really lost?

The book -- the physical paper book -- is being circled by a shoal of sharks, with sales down 9 percent this year alone. It's being chewed by the e-book. It's being gored by the death of the bookshop and the library. And most importantly, the mental space it occupied is being eroded by the thousand Weapons of Mass Distraction that surround us all. It's hard to admit, but we all sense it: it is becoming almost physically harder to read books. I think we should start there -- because it shows why we need the physical book to survive, and hints at what we need to do to make sure it does.

In his gorgeous little book The Lost Art of Reading -- Why Books Matter in a Distracted Time, the critic David Ulin admits to a strange feeling. All his life, he had taken reading as for granted as eating -- but then, a few years ago, he "became aware, in an apartment full of books, that I could no longer find within myself the quiet necessary to read." He would sit down to do it at night, as he always had, and read a few paragraphs, then find his mind was wandering, imploring him to check his email, or Twitter, or Facebook. "What I'm struggling with," he writes, "is the encroachment of the buzz, the sense that there's something out there that merits my attention, when in fact it's mostly a series of disconnected riffs, quick takes and fragments, that add up to the anxiety of the age."

I think most of us have this sense today, if we are honest. If you read a book with your laptop thrumming at the other side of the room, it can feel like trying to read with a heavy metal band shrieking in front of you. To read, you need to slow down. You need mental silence except for the words. That's getting harder to find.

No, don't misunderstand me. I adore the web, and they will have to wrench my Twitter feed from my cold dead hands. This isn't going to turn into an antedeluvian rant against the glories of our wired world. But there's a reason why that word -- 'wired' -- means both 'connected to the internet' and 'high, frantic, unable to concentrate.'

So in the age of the internet, physical paper books are a technology we need more, not less. In the 1950s, the novelist Herman Hesse wrote: "The more the need for entertainment and mainstream education can be met by new inventions, the more the book will recover its dignity and authority. We have not yet quite reached the point where young competitors, such as radio, cinema, etc, have taken over the functions from the book it can't afford to lose."

We have now reached that point. And here's the function that the book -- the paper book that doesn't beep or flash or link or let you watch a thousand videos all at once -- does for you that nothing else will. It gives you the capacity for deep, linear concentration. As Ulin puts it: "Reading is an act of resistance in a landscape of distraction... It requires us to pace ourselves. It returns us to a reckoning with time. In the midst of a book, we have no choice but to be patient, to take each thing in its moment, to let the narrative prevail. We regain the world by withdrawing from it just a little, by stepping back from the noise."

A book has a different relationship to time than a TV show or a Facebook update. It says that something was worth taking from the endless torrent of data and laying down on an object that will still look the same a hundred years from now. The French writer Jean-Phillipe De Tonnac says "the true function of books is to safeguard the things that forgetfulness constantly threatens to destroy." It's precisely because it is not immediate -- because it doesn't know what happened five minutes ago in Kazakhstan, or in Charlie Sheen's apartment -- that the book matters.

That's why we need books, and why I believe they will survive. Because most humans have a desire to engage in deep thought and deep concentration. Those muscles are necessary for deep feeling and deep engagement. Most humans don't just want mental snacks forever; they also want meals. The twenty hours it takes to read a book require a sustained concentration it's hard to get anywhere else. Sure, you can do that with a DVD boxset too -- but your relationship to TV will always ultimately be that of a passive spectator. With any book, you are the co-creator, imagining it as you go. As Kurt Vonnegut put it, literature is the only art form in which the audience plays the score.

I'm not against e-books in principle -- I'm tempted by the Kindle -- but the more they become interactive and linked, the more they multitask and offer a hundred different functions, the less they will be able to preserve the aspects of the book that we actually need. An e-book reader that does a lot will not, in the end, be a book. The object needs to remain dull so the words -- offering you the most electric sensation of all: insight into another person's internal life -- can sing.

So how do we preserve the mental space for the book? We are the first generation to ever use the internet, and when I look at how we are reacting to it, I keep thinking of the Inuit communities I met in the Arctic, who were given alcohol and sugar for the first time a generation ago, and guzzled them so rapidly they were now sunk in obesity and alcoholism. Sugar, alcohol and the web are all amazing pleasures and joys -- but we need to know how to handle them without letting them addle us.

The idea of keeping yourself on a digital diet will, I suspect, become mainstream soon. Just as I've learned not to stock my fridge with tempting carbs, I've learned to limit my exposure to the web -- and to love it in the limited window I allow myself. I have installed the program 'Freedom' on my laptop: it will disconnect you from the web for however long you tell it to. It's the Ritalin I need for my web-induced ADHD. I make sure I activate it so I can dive into the more permanent world of the printed page for at least two hours a day, or I find myself with a sense of endless online connection that leaves you oddly disconnected from yourself.

T.S. Eliot called books "the still point of the turning world." He was right. It turns out, in the age of super-speed broadband we need dead trees to have living minds.

Johann Hari presents a regular podcast, uncovering the news you won't hear elsewhere. You can subscribe via i-Tunes or click here.

For updates on this issue and others, follow Johann on twitter at www.twitter.com/johannhari101. Johann Hari is a writer for the Independent. To read more of his articles, click here or here. You can email him at j.hari [at] independent.co.uk and follow him on Twitter at www.twitter.com/johannhari101

