The quality of the air at Schloss Goring is often less than ideal, particularly when frying sausages for a partner who likes them almost charcoaled.

The fug of smoke this generates is nothing, however, to the shade of blue the air turned when I read that in some American universities, novels such as The Great Gatsby and Mrs Dalloway are being tagged with "trigger warnings" alerting students to potentially disturbing material.

Concerned that the "scenes of gory, abusive and misogynistic violence" in F Scott Fitzgerald's masterpiece, or the suicidal tendencies of a returned soldier in Virginia Woolf's haunting tale, might upset undergraduates, activists at Rutgers University in New Jersey, and elsewhere, are introducing a system to warn readers of what lies within. As an academic at Oberlin College, Ohio, wrote, of Chinua Achebe's Things Fall Apart, "it may trigger [a negative response in] readers who have experienced racism, colonialism, religious persecution, violence, suicide and more."

Why would anyone take an English literature course if they were so fragile they could not cope with the emotions great literature deals with? That is not the main issue, however. The problem with such tagging is that it grossly insults the book itself and literature in general. All other arguments against such overprotective coddling are as nothing to the sheer ignorance such a process displays for the art of writing.

The shelf by my chair, where I read about this new practice, is filled with great books: several Herman Melville novels, including Moby-Dick, Jonathan Swift's Gulliver's Travels, countless Philip K Dick novels and John Updike's collected short stories. Not one of these is sweet or safe, and some will doubtless throw up ideas and images that will be challenging or profoundly unsettling. That is what literature is about.

Faced with the concept of trigger labelling, I find myself almost unable to think of a book that is not in some way provocative, beyond those for infants and toddlers. Even then, some children's books contain decidedly alarming ideas: young rabbits being chased by angry gardeners, wild creatures entering a boy's bedroom, a hairy monster tracking a mouse through the forest. We read, it would seem, as much to learn how to handle our inner psychological weather and the troubles we encounter in real life as for escapism of the saccharine sort.

Almost all first-class fiction revolves around painful issues of some sort. Trying to protect readers from the corrosive aspects of life is akin to sending a child out into the world without their vaccinations. Toni Morrison's novels leave one sickened at racism, sexism, and mankind's capacity for cruelty. To avoid her books, however, for fear of stirring bad memories, is to allow distressing experiences to control us. Books, on the other hand, help liberate readers, giving them greater power over themselves, and how they handle what they have endured.

Of course, the old-fashioned views found with writers from other eras can seem objectionable today. Dickens's sentimental sexism is legendary, as is Norman Mailer's; casual racism and anti-semitism are widespread for many writers before the 20th century, and snobbery just as common, few more overtly class conscious than Jane Austen or Evelyn Waugh.

Yet writers are mirrors of their times, and a saintly novelist does not and never will exist. We read not to encounter perfect, politically correct or sanitised characters, but to enter the author's imagined worlds, warts and all. Strip out all conflict or fear, prejudice or unpleasantness, violence, death or heartbreak, and you'd have nothing but Janet and John storybooks.

For that matter, I can't think of a good book that has been written out of malice, or of a novelist who intended to belittle anyone, or portrayed violence without good reason, or wanted to have any effect upon their readers other than to entertain them, and perhaps also help them see things differently or more clearly. Universities should be encouraging such an education, not stifling it at birth.