It is unusual to imagine Charles Dickens as a young man. A new film does just this. In The Man Who Invented Christmas, Dickens is not the bearded patriarch and arch-sentimentalist of Victorian culture, but a young chap startled by his sudden fame and with no confidence that it will last. Dan Stevens’s kinetic incarnation of Dickens is all anxious twitchiness, his youthful energy scarcely held in. He has written a sequence of bestsellers, but his last couple of books have been “flops”. Now, in 1843, he needs another hit. So – with the help of his bosom friend John Forster, an (invented) Irish maid, whose ghost stories told to his children he overhears, and his habit of spotting vivid characters among people he meets in the street – he dreams up A Christmas Carol. And, incidentally, teaches all of us what Christmas should be like.

Stevens, at 35, is a few years older than Dickens was at the time. With five novels behind him and another, Martin Chuzzlewit, appearing in monthly instalments, he was still only 31. The young Dickens was a dandy, as dashingly dressed as he is in the film and almost as handsome. He had made it from lowly origins and was ready for the high life. A painting of him by Daniel Maclise in the National Portrait Gallery shows a lustrous-haired buck in his late 20s, his suit as shiny as his locks, gazing into the distance while his silk cravat spills down his chest.

At the beginning of the 1840s, Dickens was not quite on the ropes, but Barnaby Rudge, the historical novel over which he had long brooded, had been less popular than his first four novels and sales of Chuzzlewit were proving disappointing. More to the point, his outgoings, now that he had moved into an elegant home near Regent’s Park and had a growing family, were becoming larger.

Facebook Twitter Pinterest On the up ... Daniel Maclise’s portrait of a young Dickens. Photograph: Alamy

The film takes some forgivable liberties to try to create a sense of crisis in Dickens’s career (did he ever suffer from writer’s block?), but at least it jolts us into thinking of him as he once was: a fresh life force in English fiction, a fearless experimenter who lived by his gift for improvisation. His early books had introduced new voices to the novel – or, rather, a new way of embodying voices on the page. It is not enough to say that his characters had singular ways of speaking. In a Dickens novel, a character’s manner of speech was less a way of communicating than of unleashing the self. You can see it – or hear it – in the first instalment of his first novel, The Pickwick Papers. As soon as the loquacious Jingle enters, warning Pickwick to mind his head on a low arch, we are in a new world.

Terrible place – dangerous work –other day – five children – mother –tall lady, eating sandwiches – forgot the arch – crash – knock – children look round – mother’s head off – sandwich in her hand – no mouth to put it in – head of a family off – shocking, shocking!

The energies of speech course through the early fiction, turning bit-part players into bards of nonsense prose. Here is Mrs Nickleby, recalling her early married life with her brand of self-important free association.

I think, that very few young married people can be exposed to such temptations. There was one family in particular, that used to live about a mile from us – not straight down the road, but turning sharp off to the left by the turnpike where the Plymouth mail ran over the donkey – that were quite extraordinary people for giving the most extravagant parties, with artificial flowers and champagne, and variegated lamps, and, in short, every delicacy of eating and drinking that the most singular epicure could possibly require. I don’t think that there ever were such people as those Peltiroguses. You remember the Peltiroguses, Kate?

Dickens had brought to fiction the combination of ferocious satire and absurdity, making even child abuse funny. Nicholas Nickleby is appalled when he first witnesses the modus operandi of Yorkshire’s nastiest schoolmaster, but we can laugh.

In default of a better answer to this question, the little boy screwed a couple of knuckles into each of his eyes and began to cry, wherefore Mr Squeers knocked him off the trunk with a blow on one side of the face, and knocked him on again with a blow on the other.

In Chuzzlewit, a study in hypocrisy releases the comic energies of language when we see Mr Pecksniff affecting moral loftiness, “towering on tiptoe among the curtains, as if he were literally rising above all worldly considerations, and were fain to hold on tight, to keep himself from darting skyward like a rocket”. Manuals of good style tell you not to say “literally”, but Dickens dares offend.

What won readers allowed invention. He had learned to use serialisation to maximise sales and to concentrate the energies of narrative. He exploited the gaps between instalments to stir the interest of readers, while managing to make each part the epitome of the whole, so readers would regain their sense of the novel’s overall narrative shape. Some of the distinct features of Dickensian characterisation – the physical tics or the verbal habits of his characters – were designed to bring a person back into the memory.

Commercial requirements drove Dickens to audacious innovations. In 1843, none of the other great Victorian novels had yet been written. In The Man Who Invented Christmas, Thackeray is shown as the more confident and successful man of letters, condescending to Dickens in the dining room of the Garrick Club. Yet Thackeray at the time was essentially a prolific literary journalist, who had produced only one short, unsuccessful novel. Dickens was forging a path that the others followed. He showed how the novel could be popular yet daring, capacious yet true to the ordinary pains of one individual’s experience. He proved that you could experiment and still sell books.

Perhaps he most influenced later novelists by showing them how hard, and how inventively, they could negotiate. Dickens was the first novelist openly to play publishers off against each other. He foresaw the possibility of what is now called the book auction. The film makes him reliant on Forster, who does all the negotiation, while Dickens is in a whirl of unworldly desperation. In fact, he relished doing deals. After the huge success of his early novels, particularly The Old Curiosity Shop, he worked out that his publishers were making more money than himself and he set about changing the balance of profits. He asked for and obtained unprecedented advances; he switched publishers when dissatisfied; he multiplied the forms in which his fiction appeared (not only serialised and in multiple-volume books, but also cheaper one-volume editions and special editions for the train traveller).

With splendid red binding and expensive illustrations, the book was to be a delightful festive object and a topical tale

What the film catches is the fact that commercial ambition as much as literary aspiration made A Christmas Carol. With its splendid red binding and expensive illustrations, the book was to be a delightful festive object as well as a topical tale. Characteristically, Dickens set out to transform an unliterary genre, the ghost story – fodder of magazine fiction – into a moral satire, combining ghoulishness with comedy.

The film has a go at dramatising the process of literary creation. Stevens portrays Dickens at his desk, cudgelling his brains to find the name of the miser for his forthcoming tale. For the sake of the filmgoer, he has to say them out loud; there is much muttering of syllables beginning with “Scr”. “Get the name right and the character will appear,” declares this Dickens, an assertion consistent with the real writer’s beliefs. A collaborator on his journal All the Year Round wrote: “Whenever he saw a queer name he jotted it down, and he used to keep a series of small bags, filled with scraps of paper containing various memoranda of this sort, upon his writing table.”

In A Christmas Carol, his name poetry is beginning to acquire its special power. In the film, he keeps a book of names (as Dickens did latterly) and realises that his new story will take wing when he finally discovers Scrooge. It is just one of the Dickens names to have become a word. According to the Oxford English Dictionary, Pickwickian, Bumbledom, Gradgrind, Podsnappery, Pecksniffian and the Artful Dodger have also escaped from the novels in which they first appeared to designate types of humanity. The ghosts of Christmas Past and Christmas Yet to Come are still invoked in conversation as often as their only rival, Banquo’s ghost.

Facebook Twitter Pinterest Dead, to begin with … Scrooge is visited by Marley’s ghost in A Christmas Carol. Photograph: Arthur/Alamy Stock Photo

In the film, each character is imagined as someone from Dickens’s life: Tiny Tim is an invalid nephew; the Fezziwigs are jovial Londoners seen dancing in the street; Jacob Marley is Dickens’s grasping solicitor. Scrooge, played with sarcastic gravitas by Christopher Plummer, is his alter ego, rounding on the author to tell him that they share the love of money. It is true that Dickens saw his earnings as a measure of his achievement and that, in his own day and ever since, some have taken his commercial instinct as a sign of his vulgarity.

A Christmas Carol was a book for reading aloud, composed for that time of year when a family might share the thrills of a ghost story. Stevens shows Dickens composing, speaking the lines and the voices, as apparently he did. We hear fragments of the text itself, but not enough to catch Dickens’s most remarkable gift: the fizz of his sentences. Only Dickens could have begun a novel with something so ominous yet facetious as the first sentence of A Christmas Carol: “Marley was dead: to begin with.” So, indeed we begin, with the dead awakening, a joking pun and surely the most expressive colon in English fiction. Soon the narrator is reaching for what a proper literary writer should avoid: a cliche. “Old Marley was as dead as a door-nail.” The dead poetry of colloquial English revives.

Mind! I don’t mean to say that I know, of my own knowledge, what there is particularly dead about a door-nail. I might have been inclined, myself, to regard a coffin‑nail as the deadest piece of ironmongery in the trade. But the wisdom of our ancestors is in the simile …”

And so we go on, with all the embarrassing excesses of ordinary language bent to the novelist’s entertaining ends. And he always knew his ends. To dramatise the writer’s narrative choices, the film must show Dickens agonising over how to end his new novel. The ingenuous Irish maid tells him how he must conclude: don’t kill Tiny Tim! Yet all Dickens’s remaining working notes for his novels reveal an artist with a clear, sometimes ruthless, sense that a novel had to work to a conclusion encoded within its parts. Ending was another of his arts; only once – when he scrapped the original sad ending of Great Expectations – was he uncertain what to do. But at least the film-makers are doing Dickens the compliment of thinking about how he wrote, rather than just what he wrote about. For whether or not he invented Christmas, he did reinvent the novel.

•The Man Who Invented Christmas is on general release.