God bless us, every one

Yule logs, shining cheeks, fat Santas; the charitable soul, open hearts and good cheer - you could be forgiven for thinking that Charles Dickens invented the modern Christmas. Humbug, says DJ Taylor, he did nothing of the sort. But what Dickens did have to say about the festive season is one of the great achievements of British culture

Three days hence, on Christmas Eve - a crystal-clear morning, no doubt, with a fine powdering of hoar frost - I shall indulge myself in the age-old Yuletide ritual. Clad in my stoutest top-boots, and with a cockade of holly berries in the brim of my hat, I shall stride smartly past the banks of fir trees and their attendant robins down to Norwich market (was there ever such a market?), there to treat with red-faced old Mr Smiler the poulterer for the largest turkey that ever shiny golden sovereigns bought. Pausing only to fling silver sixpences at the deserving street urchins who cluster respectfully at my feet ("And a Merry Christmas to you my lads!"), I shall stride back homeward to Taylor Towers.

Therein, clad in her prettiest muslins, the wife of my bosom will stand folding candied peel into the most monstrous of Christmas puddings, while, nestling amid her skirts, yet fondly supervised by our apple-cheeked retainer Mrs Gushing, wide-eyed children tear open a stack of Christmas cards and recite each fervent message of festive cheer ("Oh papa, Sir Thomas sends his best regards and says that you shall have the post at the Admiralty"). This done, I shall retire to my study, there to recruit myself with a glass of negus against the cold, count my blessings, shed a silent tear for the sufferings of the poor, and plot anew the tremendous Yuletide revel in which each happy guest bidden to my hearth on the morrow will be compelled to take part ...

Or maybe not. And yet in a way this Dickensian reverie is not quite as far-fetched as it sounds. It is impossible to disentangle Dickens from the idea of Christmas, even in an age in which the shredded gift-wrapping is liable to reveal a PlayStation, and Christmas dinner consists of curry and naan bread rather than the Cratchits' goose. Somehow he is always there, Dickens, down among the teeming stack of artefacts which folk memory tends to credit him with having inspired - Christmas trees, Christmas cards and yule logs. And I can practically guarantee that at some point during next Thursday's Christmas dinner repast chez Taylor somebody, as a kind of festive benediction, will cheerfully pronounce the words "God bless us all, said Tiny Tim".

Curiously enough, the spiritual cord that connects festive cheer, roaring log fires and frolicsome reindeer to a writer dead these 130 years turns out to be tightly lashed to my own professional life: scarcely an early December passes without some seasoned commissioning editor phoning to enquire "Could you write us a parody of A Christmas Carol?". A contemporary writer can do this, and, more important, have a chance of being understood, because Dickens is public property in a way that most British authors, with the exception of Shakespeare and possibly Orwell, are not. Only the other day, for example, opening the Christmas edition of Viz I came upon a cartoon version of the Carol got up to satirise the London art world.

Amid a torrent of "Dickensian Christmas Fayres" and coffee table books on "Dickens's Christmas" (a new one compiled by the actor Simon Callow has been doing the rounds this autumn), it comes as something of a shock to learn that the novelist did not invent the standard conception of Christmas - and that he was at best a populariser, following keenly in the wake of cultural tendencies that were well under way when he first began to write. In fact, a thorough re-reading of A Christmas Carol, which was first published in 1843 and acclaimed from the start as an epic distillation of everything that was meant by the Christmas Spirit, soon reveals the mix to be painfully light on the classic ingredients.

There are no Christmas trees, no yule logs, no Christmas cards, fat Santa Clauses or frisky reindeer and not the sniff of a turkey. The impoverished Cratchits dine off a goose, cooked in the baker's oven down the road (a standard Christmas expedient for the poor) and drink a dubious compound of gin, hot water and lemons while a shovelful of chestnuts roasts on the fire. The newly transformed Scrooge invites his clerk to partake of a "smoking bishop" (an orange deluged with mulled wine, sugar and spice and so-called because of its purple hue), but that is about the limit of the festive cheer. The emphasis is on charity, good feeling, human warmth and - as this is a prime-time spot - for reconciliation and the burying of grievances, and family values.

The Victorian Christmas, consequently, is not Dickens's idea but something that had already begun to take shape around him. There had been earlier prototypes, but the first Christmas card appeared in exactly the same month as the Carol, featuring an intensely Dickensian triptych of a middle-class family lofting their glasses in a toast while beyond the window the meekly deserving poor are fed. Christmas crackers were the invention of a Victorian confectioner named Tom Smith, who planned to enhance the allure of his bonbons by packing them in exploding cardboard cylinders.

Christmas trees - a staple of the Mitteleuropa Christmas and therefore favoured by Hanoverian kings - were brought to wider notice in the 1830s by German merchants living in Manchester and given an authenticating seal of royal approval by a famous engraving of 1848 showing Victoria, Albert and their children posed in front of a much-tessellated 12-foot fir. Significantly, Dickens's famous essay "A Christmas Tree" ("Now, the tree is decorated with bright merriment, and song, and dance, and cheerfulness" etc) was written in 1850, two years after the royal tableau, to which it is effectively an approving response.

But however much strict chronology might establish Dickens as a contributor to the Victorian concept of Christmas rather than its original source, it is clear that the idea of Christmas as an overwhelming moral force fired his imagination. It's sharply apparent in even his earliest writings. Sketches by Boz (1836), his very first book, contains an affecting piece called "Christmas Dinner" in which an archetypal three-generation bourgeois family go about their preparations for the great day. Huge amounts are eaten and drunk, but Dickens's real interest lies elsewhere. The sketch ends with a reconciliation: the blacksheep daughter of the family who married beneath herself is rapturously received by hitherto inflexible papa, while her downmarket husband is acclaimed for his previously unsuspected virtues.

Even as a 24-year-old, apparently, Dickens envisaged Christmas as a spiritual call to arms, capable of dismantling any economic or class-based impediment placed in its way. His own Christmases, one gathers, were somewhat tiring affairs, such was the host's enthusiasm for his role as entertainment impresario and head reveller: certainly not a Christmas carol could be sung chez Dickens without our man leaping up to join rapturously in. Subsequently the yuletide bell clangs on endlessly in his work - in Mr Pickwick's visit to the olde-worlde festivities of Dingley Dell and, a quarter-century later, in Pip's rather more sombre experiences by his tough-minded sister's fire in Great Expectations.

Throughout Dickens's career, though, the Carol remained the public's favourite among his Christmas books: 6,000 copies were sold on Christmas Day 1843, an almost unheard-of total for the time; clergymen praised it from the pulpit; taken to America its sales soon outstripped the Bible's. All this suggests a universality of appeal, but it also guarantees a certain flexibility of interpretation. This, after all, is not much more than a full-frontal attack on many of the most cherished principles of the early Victorian age, and yet the early Victorian age was delighted by it. So tough was the elephantine hide of the mid-century capitalist gleefully plundering the proletariat and that of the newly prosperous bourgeoisie - who believed that their wealth was bestowed on them by divine ordinance - that what penetrated to the heart within was nearly always only a kind of delicious tickling.

The secret of A Christmas Carol's success, then, lay in its sheer adaptability to contemporary and latter-day needs. This extends into areas as disparate as myth, moral and economic justification and even explanations of psychological behaviour. In the years after Dickens's death in 1870 it was seen as a scriptural allegory, with Scrooge's transformation viewed in terms of Christian repentance. By the Edwardian age it had been reinvented again, as a Peter Pan-ish fairy tale, with most of the emphasis placed on Scrooge's avuncular, child-friendly redemption. Later on, in the Depression-bound 1930s, the book became a propaganda parable on both sides of the Atlantic. The 1935 British film version, for instance, carries a richly symbolic treatment of the Lord Mayor's banquet: the rich carousing within, the poor waiting outside. At the climax both groups join together to sing the national anthem, a display of national solidarity from which only Scrooge, gnawing his dinner in solitude, is shut out.

For a generation of New Deal Americans, on the other hand, A Christmas Carol was proof that capitalism was "safe" - a profitable economic system for rich and poor alike. Scrooge, Roosevelt's economists noted with relief, stays wealthy. Cratchit's pay rise is his boss's idea. The victory was won by common welfare, not insurgent labour.

The last half-century has brought dozens of other Scrooges. A 1951 film version, starring Alistair Sim, offered an almost Freudian creation - vulnerable, troubled, insecure - and in addition feminised by the carving out of a substantial role for the hitherto marginal figure of his cockney housekeeper, Mrs Dilber. The "internalised" Scrooge gave way in the early 1980s to a vindication of supply-side economics, when a hapless presidential economic adviser named Edwin Meese declared him to have been "the victim of a bad press". Whatever else Scrooge might have done, Meese (predictably christened "Edwinezer" by his opponents) alleged that at least "[Scrooge] wasn't unfair to anyone".

It scarcely needs saying, in the wake of Peter Pan, Freud and the National Government, that there is a Triple X video porn film entitled The Passions of Carol: the thought of a cultural flagship long detached from its original moorings and borne off into uncharted seas is unavoidable. Ask what this ceaseless process of reinvention does for Dickens's template, and the answer - aside from stressing its value as a universal signifier - is: not very much. Certainly A Christmas Carol is propaganda, the equivalent of a stick of dynamite placed under the average Victorian chaise longue, but its message is moral, not economic.

Turn Scrooge, the miser who lurks in his counting house alone and "solitary as an oyster" into a spokesman for Reagan-era economics, and inevitably the Dickensian behavioural imperative slips away. Sitting to re-read it for the nth time, I discovered that the parts I remembered best, and liked the best, were not Scrooge's nightly visitations or even his transformation but the scenes around the Cratchits' straitened Christmas hearth and the sight, so rarely achieved in fiction, of morally "good" people impressing you by their goodness.

The "moral" of A Christmas Carol, as with most of Dickens's books, is fairly straightforward: the world would be a much more agreeable place if we all behaved better towards each other. It is a measure of the grip that Dickens still holds on the national psyche that this should seem one of the most profoundly important things that a British novelist ever said.