A session at last weekend's conference of the British section of the International Board on Books for Young People considered these questions. Participants asked whether novels which seek to teach young people about the evils of the world - oppression, abuse, war, the Holocaust - might be in danger of overloading readers with too much violence, too much misery, before they are ready.
The South African writer Elana Bregin's response to her country's recent history in her novel, The Slayer of Shadows, is at the centre of a related controversy in Cornwall, where it was withdrawn from school libraries earlier this year. Bregin's story of a young African girl's struggle for survival contains graphic descriptions of a vicious mob-killing and a gang rape. These passages were at the head of a list of objections from staff at Torpoint School, who were alarmed when the book appeared in their library, which is used by 11 to 16-year-olds.
Tricia Ellis, head of the secondary education library service for Cornwall, says The Slayer of Shadows would not normally have been offered to schools for readers under 16 - it had not been sent to the central library service on approval, but had reached Torpoint via a local supplier. "It is up to schools to select for their libraries, but we advise as much as we can. Nobody wants to be seen to be censoring, but we are taking the place of a parent until the reader is 16. We do not recommend books with extremely violent scenes, very strong language or explicit sexual content."
Torpoint headteacher Roy Bright, who complained to Bregin's publishers, The Bodley Head, argues that The Slayer of Shadows contains more disturbing material than should reasonably be expected from a children's publisher, whatever the intended reader's age. The book's cover says it's "a powerful novel for young adults" and the blurb on the back refers to "the story of the spirit's resilience against even the most brutal of assaults", but Mr Bright feels a stronger signal of the contents is in order.
"How can we be reasonably sure what is in novels published for children if we do not have time to read every title ourselves? We do our best to keep up and we rely a lot on the library service, which is excellent, but they cannot read everything either. We need more guidance from publishers. Some sort of age indication on the cover, perhaps," says Mr Bright. "We do not want to take a prudish line - we were happy to have Judy Blume's Forever (a 1976 novel about teenage sex) in the library, which some people may have thought was controversial - but such explicit violence is not acceptable."
In a spirited defence of the book, The Bodley Head's publishing director, Anne McNeil, says that it "unequivocally condemns the violence which it describes" and that the author "chooses not to underestimate her audience, who live in the real world, who have access to TV and newspapers". She adds: "We knew that the book might offend some members of the wider community but we felt that it was an important story that needed to be told. We do realise that we have a reponsibility to children not to mislead or corrupt. We take this responsibility seriously."
Her correspondence with Torpoint has raised several questions about responsibilities to that elusive creature, the young adult reader, who is getting younger. As McNeil says in her latest letter to the school, this group "is deemed by some to need protecting and by others to need challenging" en route from Goosebumps to Stephen King and Irvine Welsh.
The desire of many 11 or 12-year-olds for fiction with street credibility (which means that it centres on the predicaments of an older age group) draws them to novels marketed for older teenagers, especially those with a "health warning" similar to that used for The Slayer of Shadows. This raises obvious difficulties with labelling fiction for age-groups. Unfortunately, it also suggests that The Bodley Head's well-intentioned warning is inadequate. (It does not help that "powerful" is one of those bits of blurbspeak, like "haunting", "compelling" or "master storyteller", which lose meaning with repetition.) Until recently, Birmingham city libraries had their own health warning in the form of red stickers next to the date stamp, which would alert children's librarians to ask 12-year-olds or under to get a parent's permission to borrow. Now the former "red-sticker" books - about 20 titles including Blume's Forever - are in the adult sections where they compete with Irvine Welsh and Stephen King for the attention of 13-year-olds upwards.
Commissioning editors of series such as Hodder Signature and Scholastic Point Crime and Romance have become adept at persuading writers to handle topics such as incest and rape, while keeping explicit sex, violence and even swearing off the page. "We have to remember that while we may have readers who are very sophisticated in outlook, we are children's publishers first and foremost, " says Julia Moffatt, an editor for Point Horror and Point Crime.
The novels in The Beat, a Point Crime mini-series by David Belbin, a former teacher, are intended to be "harder and grittier . . . the fiction equivalent of The Bill", but the same rules apply. "There is no gratuitous violence and although some of the characters sound very aggressive, they rarely swear, " Moffatt says.
"Anything you call 'young adult' is likely to be read by 12-year-olds or younger - some Point titles are picked up by 10-year-olds. We emphasise the intended age group to our reps when they go into shops but we can't predict where the books will end up."
As Cornwall librarian Tricia Ellis says, "The quality of the writing and how a situation is handled counts for a lot." A new Signature title, Escape by June Oldham, is, says Hodder's director of children's publishing, Fiona Kenshole, "a story which deals with incest, rather than an incest book with a story tacked on. We realise that it might be read by 12-year-olds although the main character is 18. Everything is implicit, but the child who has been through such an experience will read it on a different level. However, you cannot draw too many lines about what is appropriate. Being a teenager is a lot about working things out for oneself."
Elizabeth Hammill, a children's bookseller who also co-ordinates production of In-brief, a review magazine edited by its teenage contributors, says: "Books can help kids explore issues they are concerned about without the sensationalism and titillation that might accompany coverage in the mass media. Point of view is important. You can say as much as the main character would know - and that's as much as the reader needs to know."
But, she says, "It's counter-productive to deny what children know to be true, even if it's hard to read." She argues that the nihilism of Robert Cormier, for example, is preferable to over-protective, fake happy endings.
Her conclusion is that "sometimes there need to be adults around deciding who's ready for what when". Something these adults will probably only know by reading the books alongside the young reader, or encouraging them to read with friends - bringing opportunity for context and supported reflection into what can be an isolating activity.
A deputy head of a girls' high school in the South-east uses pupils' choice of "shocking" reading material as an opportunity for discussion. "Rather than put restrictions on what they read, it's better to talk to them about why they find violence on the page attractive, for example, and find a way to move them on."
The books which are most likely to attract criticism are those which are not part of a series with a strong identity and which take on subjects of global scale which simply cannot be left off the page. The Slayer of Shadows is one example, fiction about the Holocaust is another.
Gudrun Pausewang's novel The Final Journey, published by Viking earlier this year, led one reviewer to write: "too much brutal truth too early can be wrong". No sickening detail is spared in this story of 11-year-old Alice, a passenger in a cattle truck going to Auschwitz. Even Anne Frank's diary offered some light relief, perhaps because the author was ignorant of what was to come.
Michael Smith's After the Darkness (Scholastic) tackles the same bleak chapter in history. Jean-Pierre and Lucie Cohn escape from Paris with their parents just before Jews are rounded up. Their mother is shot by the Vichy militia; their father is captured after locking them in a tower for safety. They are left to starve to death while he follows Alice's route to the death camps.
The horrific content of these books might induce despair, but they emerge as life-affirming as well because they balance the "brutal truth" against the essential goodness of the characters. Michelle Magorian's 1981 classic Goodnight Mr Tom works in much the same way - the compassion of the community that embraces a young evacuee shines in comparison to the arbitrary cruelty of his mother.
It is consoling to read in Pausewang's novel that Alice gives her possessions away to her fellow travellers; that her family was sheltered at great risk by their former employee. In Smith's book, everyday family dynamics distract from the appalling situation. The feisty Mme Cohn is no victim - she is shot for arguing with a policeman. Jean-Pierre continues to argue with his father even after they are both dead.
Alice's "final journey" is one of discovery - during the years in hiding, her grandparents had kept the truth of their situation from her to the extent of forging letters from her dead parents. Surrounded by the evidence of evil, she symbolises the reader at the centre of the "protect or challenge" debate.