There is a moment, somewhere in the middle of the latest Harry Potter film, when dear old Dumbledore turns to Harry and asks: “Confused? I wouldn’t be surprised if you were.” Too right, matey: for while The Half-Blood Prince is easy on the eye, it certainly doesn’t pretend to be anything other than a single instalment in a looooong story. If you’ve lost track of what happens in Vol. VI of Rowling’s opus, you may want to give yourself a refresher course before you head to the cinema.

I must confess that in earlier times my regard for Rowling’s work was damaged by my admittedly privileged position. A critic’s generosity can be dampened by having to read a 600-page book in an hour, starting at midnight, to file a piece for the morning paper. Mea culpa: for I now have a nine-year-old son and, a couple of weeks ago, he was looking for something to read. Try this, I said, and handed him The Philosopher’s Stone. He wasn’t too excited. He’d seen the films and thought they were fine, but not as good as Doctor Who or Star Trek.

He is now up to The Goblet of Fire and the volume must be wrested from his weary hands at bedtime, shifted from under his nose at mealtimes, pried from his grip as he walks down the street lest he walk into a lamp-post. He’s a good reader, which is maybe not surprising, but he has never read anything this way before. In case you’re wondering, he came along with me to The Half-Blood Prince and didn’t think much of it either: it was striking — and, needless to say, pleasing to one in my profession — that the characters on the page, for him, clearly trump their avatars on screen.

But then we encountered a wee hiccup. A muggle left briefly in charge of the son was alarmed when he made up a story that involved an elephant who was after revenge. (Elephants have plenty of reasons for wanting revenge, if you ask me, but I am willing to admit I may be biased.) This was indicative of a violent imagination, the muggle remarked; and inquired what he was reading. Harry Potter and The Goblet of Fire, my husband said, and the muggle was horrified. But have you read it? the question came. Do you know that a child dies in that awful book? I would never let my child read anything I had not read first! was the muggle’s cry.

Everyone is horrified by something, of course. I am horrified by the thought of turning into my child’s censor — though this does not mean I am about to let him start surfing for porn. J. K. Rowling’s books compel children — and adults — because they see in them a mirror of the world, a world that contains magic, adventure and joy, but a world where sorrow and loss exist too. It wouldn’t be going too far to say that the true role of stories in a child’s life (whether those stories are read or heard) is to prepare him or her for the trials that are to come. The giant in Jack and the Beanstalk is a pretty nasty fellow: is that story out of bounds? Cinderella’s mother has died and her step-sisters aren’t very nice to her. Call in the Social Services or just keep reading? Let’s not even start discussing what happens to the poor tots in Struwwelpeter. Literary classic or X-rated pulp fiction?

That said, it’s easy to poke fun at the library’s ’elf and safety brigade; not as easy to help your child to choose the book that’s best for him or her to read. Our children’s critic, Amanda Craig, discussed exactly this issue a couple of weeks ago in a look at some of the summer’s darker offerings for young people: including Margo Lanagan’s Tender Morsels, whose heroine, Liga, suffers sexual abuse at the hands of her father, gang rape and miscarriage at the outset of the book. When is dark too dark?

Yet the distinction between books for children and books for adults is largely a new one, a product of our wealthy, book-rich society. Readers and writers of earlier generations speak of developing their love of reading simply by reading whatever they could lay their hands on: the author Alan Garner discovered the Hindu epic The Ramayana at the age of 7 and his life was changed for ever; his adoring readers — of The Weirdstone of Brisingamen, of Elidor, of Red Shift, challenging and inspiring books in themselves — have reaped the benefit ever since.

Stories are not diversions from real life. They are preparation for it and examinations of it. From The Wizard of Oz, to Coraline, to Harry Potter and beyond, childen — and adults — will find that in confronting their fears they also discover their own, truly magical, powers.

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