“KNOWING I LOVED MY BOOKS,” says Prospero, talking of his flight from Milan with only his daughter and his library.

Prospero's books remake the barren island of his exile into a place where things are always happening — the books themselves bring life. This must be because the books themselves are life, exuberant and powerful, contained in a handy format that can be easily transported.

Prospero's flight was not dependent on the airline authorities. In those days flights were made by boat or horse, and much the better for it. No one was suggesting that books could not be taken as hand baggage. I have to confess that if the airlines had not relaxed this new threat to our sanity, I would have given up flying for ever.

The indignities and discomforts forced on us by those who claim to be acting in our best interests cannot include confiscation of our books. If airlines are going to oblige us to go about with unboxed sanitary items, like prison inmates, and without so much as a toothbrush on board, then leave us with a book — even ones dished out at the gate. I will be quite happy with an airline library, as long as it includes The Oxford Book of English Verse, as well as The Da Vinci Code.

The theory is that books can be hollowed out to contain Devices. Mrs Winterson always objected to book reading on the grounds that: “The trouble with a book is that you never know what’s in it until it's too late.”

How true. Anybody who spends time with real books knows that they are dangerous objects likely to blow up in your face. Good books are detonating devices, and able to trigger something in the mind of the reader — a memory perhaps, or a revelation, or an understanding not possible by other means. Not for nothing was Madame Bovary kept away from trapped French housewives. Who can forget the infamous review of Radclyffe Hall’s The Well of Loneliness? “I would rather give a healthy boy or a healthy girl a phial of prussic acid than this book.”

The celebrated censorships — such as Lady Chatterley’s Lover or The Satanic Verses — are only the extroverted signs of a matter that goes much deeper; how fiction and poetry and plays affect our lives all of the time, if we let them.

The introverted nature of reading — you and the book, private and solitary — is part of its power. No one knows what you are thinking as you read. No one can see what changes might be taking place under the surface of your silent repose.

I have argued before that it is this unaccountability to external authority that makes reading both defiant and an act of free will. The CCTV and the webcam, the bugged phone and the surveillance systems can do nothing about the private dialogue between reader and writer. When books are banned or censored we concentrate on their content, forgetting the more sinister implications of what reading stands for, and why it poses a threat.

My mother didn’t allow books in our house because she didn’t want me to read them — simple as that. At least it was clear, just as we know there is something to fight against when books are piled and burned.

Our world, the world of soft power, where people are persuaded to believe that they want the lifestyle, the commodities, the cheap celebrity, that the money-mongerers want them to want, has done something much more complicated to books than to ban them. Freedom of choice, as it is called, floods the market with trash, so that readers are genuinely bewildered about what is and isn’t worth the time, and books are marketed as five-day-wonder disposable objects. Bookshops are no longer places to browse. Reading itself has been downgraded from something that matters, to something you might do when your iPod is broken or there is nothing on TV.

We are not supposed to say that some books are better than others, or that reading them can make a difference to the way we understand ourselves, and ourselves in the world.

The fact is that real books teach us how to read between the lines. That is a skill that everyone needs these days. You may think that the better newspapers can do that for us, but I don’t believe in passivity of any kind. Thinking for yourself is not only an intellectual exercise — it is an imaginative leap. Books make the leap.

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