Will anyone get the picture?

Like quite a lot of people, I suspect, I am hopelessly susceptible to those little handwritten commendations you find in the livelier kind of wine merchants. My wine-buying, in fact, is a perfect definition of philistinism. I know what I like and don't stray very far from it; I'm childishly swayed by superficial details, like the design of the label; and I'm a pushover for vigorous opinion with a personal touch.

Like quite a lot of people, I suspect, I am hopelessly susceptible to those little handwritten commendations you find in the livelier kind of wine merchants. My wine-buying, in fact, is a perfect definition of philistinism. I know what I like and don't stray very far from it; I'm childishly swayed by superficial details, like the design of the label; and I'm a pushover for vigorous opinion with a personal touch.

So, while I like to think I'm sophisticated enough to discount the pre-printed enthusiasm of chain off-licences as routine commercial hype, I'm also gullible enough to accept the recommendations of the Australian backpacker who's doing a bit of crate-shifting to buy his ticket home. I'm a bit less credulous in bookshops, but even there I can't guarantee that one of those cursive, home-cooked blurbs on the shelves won't tip the balance and turn a browse into a purchase. What both off-licences and bookshops have found is a way to synthesise that most desirable and yet elusive kind of advertising - word-of-mouth recommendation.

At first glance, Tate Britain's decision to celebrate British Art Week by inviting the public to submit their own descriptive labels for works in the gallery looks like a more democratic version of this technique. They've tried celebrity endorsement, with Sian Lloyd and Michael Palin contributing their thoughts on Turner paintings. Now anybody can have a go, although the website encourages those with a special interest in the subject matter of the paintings to step forward first.

"Have you experienced an event shown in one of the paintings?" they ask - an open invitation for experienced swan-uppers to give a professional view of Stanley Spencer's painting of the annual roundup at Cookham, or for anybody who's seen the ghost of a flea to tell us whether William Blake got the details right.

It is, in two senses, a crowd-pleasing exercise - it flatters visitors with the implication that their responses are just as important as those of the Courtauld-trained experts, but it also hopes to kindle an enthusiasm for artworks by adopting a less forbidding diction. Just as the wine recommendations steer clear of oenophile jargon in favour of robust phrases like "stonking fruit", "juicy" and "amazingly cheap", these labels are likely to be aimed at the general reader. It's a kind of decoy-duck principle of marketing. Look, here are all the signs of an ordinary sensibility having a good time. Why not overcome your natural wariness and join the flock?

It wouldn't be very difficult to get sniffy about this. Indeed, the more high-minded purist would probably take the view that the existing labels are already bad enough, getting between the work and the viewer in a way that is clunky, crass or coldly academic. And if they provide a bolt-hole for viewers who recoil from the often tricky task of really looking at pictures, won't the public's captions - leaning heavily towards the sentimental and anecdotal - be even more of a distraction? Vox pops - and, in effect, this is one - usually leave you little wiser about anything but how thinly spread wisdom is.

There is another model for the amateur exchange of views, though, which isn't inconsistent with more thinking rather than less. The passion for reading groups relies on a similar desire to make the business of art appreciation (and comprehension) a little less lonely - but it depends absolutely on dissent and argument. Tate Britain has already tried this - in a modified form - with the democracy wall it usually erects for the Turner prize exhibition; a stretch of gallery on which the public can pin their opinions about the shortlisted artists, which has proved something of a hit in recent years.

Indeed, not a few visitors spend more time looking at this section than at the individual works of art themselves. It's gobby, ignorant, incisive and silly by turns - but it is also a kind of collaged public conversation. And one of the striking things about it is the way that disagreement with the opinions expressed often crystallises your feeling about the work far more clearly than agreement.

One hopes that those responsible for winnowing out the contributions for public labels will bear this in mind and let through a bit of intelligent contradiction as well as plain-speaking enthusiasm. A culture isn't just goods for sale, pitched to the consumer as an aesthetic "best buy", it's the arguments you have about the objects - and disapproval is an absolutely crucial ingredient in the mix.

As Valéry put it, taste is made up of a thousand distastes. I can understand that they might not have room for that many on the walls of Tate Britain, but even a few would be invaluable.