When I’m oldy mouldy (as my kids used to say of anyone over 12) — perhaps toothless, foul-tempered, smelly, but likely all three — a palliative comes to mind. I tell myself that I’ll always have my books. I’ll still be able to see the splodges of British painter Howard Hodgkin. I’ll still hate American sculptor Richard Serra, who makes great, big, stupid, iron traffic-blockers. And I’ll be playing Rufus Wainwright very, very loud. Ooooh, I’ll lurve my comforts.

Justify your love, demands Oxford English literature professor John Carey. One of Britain’s great critics, he has just written a little stunner of a book called What Good Are the Arts? He takes every possible answer, macerates it, and concludes, “Not much good.”

Prof. Carey says art cannot be evaluated. First, rightists look at its economic value, a realm in which art does not belong and which consistently gets prices wrong anyway. Second, scientists study its ability to stimulate the brain, which it does, but then so does everything. Third, it was argued for centuries that “high” art put us in touch with the sacred, but Prof. Carey argues that this is a religious argument, and therefore off the table.

Finally, people like me firmly believe that art makes us better people. Now, one man’s logic is another man’s lunacy — “I must invade Iraq because Osama bin Laden has no connection with the place” — but logic and the arts have never played nice.

I, who have several snobbish bones in my body, now believe that Stephen King is a great writer. Prof. Carey would insist I apply logic to my admiration. How are Mr. King’s novels better than those of the greatest writer of our times, Doris Lessing? I say that Ms. Lessing nails the human race while Mr. King’s novels are so scary that I’m too frightened to read them. One makes me think; one puts me in the fetal position.

And you call that logical evaluation, Prof. Carey responds politely.

The professor, disgusted by social injustice, wrote a famous book called The Intellectuals and the Masses, in which he argued that the modernists (T.S. Eliot, James Joyce et al) disliked the increasing literacy of the working class and set out to write literature that would be opaque to them. They used art as a badge of status.

The distinction between “high” art and “low” art is so maddening that it makes people’s hair bleed. You cannot win. If you find conceptual art appalling (last month, a British conceptual artist left a tap running in a gallery to waste 200,000 gallons of water deliberately), you are a Philistine. If you despise “low” art, you miss out on rock ‘n’ roll.

But if you’re what I call In Tray and Out Tray, très in (because you like Top 40 ballads) and outré (because your favourite sculpture, Kiki Smith’s Train, is of a naked woman leaving trails of menstrual blood), you might as well give up. High and low: You can’t have both. Actually, you can, but keep your voice down.

The snobbishness of the art world makes it almost impossible for a sane person, educated or not, to enjoy painting, music and books openly. The art world despises the arts of the masses — makeup, fashion, etc. and what Prof. Carey says is arguably the greatest art we practise, gardening — and yet museums are begging for tax money from the masses. They cannot bring themselves to find a middle ground.

But there is a method in the madness, Prof. Carey says. It is “class-imitation, the process whereby upper-class fashions are imitated by the lower, so exerting a perpetual pressure on the upper classes to innovate.”

Art is all about class, he says, and this makes it even more difficult to define art. It is in the eye of the beholder, who is defined by his class. A liberal-minded art lover wants galleries opened to the public because he believes it will improve the poor. But Prof. Carey argues that art cannot improve anybody morally.

So art is art only if someone calls it art. No thinking person has ever been able to find the gold standard, the definition of great art. We have opinions, nothing more.

Only one art stands a chance at making us better humans: literature. It is “the only art capable of reasoning, and the only art that can criticize,” Prof. Carey says. Language is the universal medium; it is capable of limitless flexibility and range of thought and it enlarges your mind.

The key to all this is a quality we have been taught to disparage: indistinctness. It is very difficult to analyze words in a poem or a novel; they might mean various things to various readers. And thus the world expands. Prof. Carey says precision in literature can cramp the brain, for it leaves no room for exploration.

A new American book, Everything Bad is Good for You, argues that playing video games raises IQ scores and “develops cognitive abilities that can’t be learned from books.” The author’s error is his failure to distinguish between cognition and intellect.

For example, I recently read about an American man who died of a ruptured colon after sexual intercourse with a horse. The response of a video gamer with his excessively fast cognitive abilities learned from SimCity would be: “Arrest that rapist horse!” The intellectual response from someone who thought things out, i.e., had read about horses, perverts and a recent interview with violent American anti-abortionist Neal Horsley on his close boyhood friendship with a mule? It would be a blast of theories involving an oat bag, possibly an apple, and a highly limber man who died happy.

Video gaming may well be the equivalent of taking your brain to gym class. When it comes to the convincing use of language, best stick to acres of reading and the application of logic. You can test cognitive ability. As for the arts, you can’t measure taste. I suspect that this is the source of its power.