As the cinema has so powerfully told us: everybody enjoys waking up to be surprised by a horse's head.

That may be why, this Christmas, John Lewis is selling a "decorative horse head" for £30.

If you're looking to spend a bit more on your beloved, for £70 you can get a wall-mounted one.

In the higher price range, you are not restricted to a horse. When it comes to wall-mounted heads, John Lewis offers all the main animals: tiger, monkey, elephant, pig or triceratops. ("With a large frill and green reptilian skin," explains the website, "the triceratops is one of the most recognisable dinosaurs of the Cretaceous period." Oh, that triceratops.)

You might wonder why I know so much about the different types of disembodied head currently available at John Lewis. Well, after seeing its recent, much talked-about TV commercial, I determined to buy all my Christmas presents there.

This is partly because of the advert itself (in which a cartoon hare tries to prevent a bear from hibernating in order that they might spend Christmas together) and partly because of what Alan Sugar said about it.

"Have not got a clue," tweeted Sugar, "what they are trying to sell."

And this is the point. They spent £7m on a commercial that doesn't actually persuade us to buy anything. The only visible product is an alarm clock, which the hare gives the bear to wake it up on Christmas Day. And nobody wants an alarm clock for Christmas. That's no sort of present. The best you can say about it is that it would be marginally better than a severed monkey's head.

I believe this is part of a deeply subversive plan from John Lewis. Bear with me.

For years, people have been complaining that we've lost the "true meaning of Christmas" in its commercialisation: the early advertising, the November street decorations, the blaze of high-street greed. This has been a cliche for so long that we may not have noticed a shift in its central principle.

The high street is no longer a rapacious salary-Hoover, growing fat on its exploitation of our seasonal goodwill.

The high street is dying. Punched once by the introduction of out-of-town malls, a second time by the rise of internet shopping and a third time by recession, it is barely even on its knees any more.

These days, buying your Christmas presents from an actual shop, near your actual house, would be an act of charity. The snowman-filled windows aren't triumphant pieces of manipulation, they are desperate cries for help.

John Lewis isn't your local corner shop, of course. It's a retail giant with a healthy online arm. But it is still, first and foremost, a bricks-and-mortar operation. Besides, it has always been one of the good guys. Hence my theory of subversion.

Its £7m advert clearly implies: "I shouldn't bother getting your Christmas presents at John Lewis, if I were you. We're good on the practical stuff like alarm clocks. We don't do 'gifts' very well."

They're not wrong there. Let's have a look at some of the items currently on sale in the John Lewis gift department.

For £2, you can get a cheese grater shaped like a turtle. In heaven's name, why? Nobody wants to be given a cheese grater of any description. And if you're buying yourself a cheese grater, you don't want it to be shaped like a turtle.

For £8, you can get a purse shaped like an owl. The website explains: "This knitted owl is the perfect buddy to carry your spare change." (No it isn't. There is nothing good about putting your change in an owl.)

Also retailing at £8 is the "John Lewis decorative apple with leather leaf". The website advises: "Completed with a leather leaf, hang it from shelves and plants to create points of intrigue." (The main point of intrigue being: "Why did you spend £8 on a leather apple?")

Up the stakes to £20 and a "John Lewis ceramic playing card (large)" could be yours. Ooh, you're thinking, what does that do?

Nothing. It doesn't do anything. It is just a large ceramic playing card.

If you have £30 to spend, why not buy a set of "stacked resin elephants"? I'll tell you why not. Because it is a set of stacked resin elephants.

Come on, these "gifts" are utterly surreal. Resin elephants, ceramic playing cards, decapitated dinosaur wall-hangings? You might as well go into a hardware shop and ask for a long stand.

I genuinely think these were designed, by someone quite brilliant, as a parody of the very principle of gifts. Stare long enough at a turtle grater or a change-owl and (I speak from experience) you will find yourself thinking that all the crap we splurge our money on at Christmas is ridiculous and without meaning.

The second, tear-jerking message of the John Lewis advert is, of course, that only love matters. The hare receives no gift, but enjoys its happiest Christmas ever. So the subversive message is: something has gone wrong with the way we spend. Boycott those tax-dodging websites. Ignore those glittering malls. Stop exchanging leather apples and horse heads.

With the two-pronged attack of parodic stock and product-free advertising, the John Lewis Partnership is saying: "Just don't buy anything at all. It's Christmas. Hold fire, calm down and be nice to each other."

Who would have thought that the very message we once said was "swept away by commercialism" would, one day, be brought back to us by commercialism itself?

They're not morons, obviously. There is a fourth and final message: remember the old shops you love and trust, such as, ahem, John Lewis, when you actually need to buy something. Something proper.

Like an alarm clock.