There are six cinematic adaptations of Madam Bovary, but not one biopic of her creator, Gustave Flaubert. This should come as no surprise; unlike his most famous heroine, Flaubert lived a life spiced with about as much sensation as the shipping forecast. It is probably beyond even the most unscrupulous screenwriter in Hollywood to enliven the tale of a man whose most intense relationship was with his mother.

But a greater obstacle would stand in the way of such a screenwriter, and indeed in the way of any adapter of any writer’s life. It is that writers, from day to day, are usually far more boring than we would like them to be. Flaubert said that as a writer you should be ‘regular and orderly in your life, so you can be fierce and original in your work.’ Though there are many writers who would like to be thought never to do a full hour’s serious work, there are almost no great ones to which this dictum does not apply. Great literature does not result from a rapturous gaze at the stars, or walk through a meadow, followed by half an hour of frantic scribbling. It results from sitting at the desk, hour after hour, and returning to it, day after day. The problem for film makers is that sitting at a desk is not particularly interesting to watch. It cannot be hammed up, because even if the writer’s experience is dramatic, all the drama takes place in his or her head. Viewers of Amadeus, Milos Forman’s otherwise good biopic of Mozart, should snort with laughter when the Maestro actually sits down to write his music. The moment he begins to pump his fist to the beat of imaginary drums is the moment we cease to believe we are watching Mozart at work.

Of course an actor needn’t necessarily spend a minute writing to convince us their character writes most of the time. But that actor’s job, of suspending our disbelief, is made much harder if what we are to believe cannot be shown. Imagine the same dilemma in films about other trades. Imagine Whiplash with no drumming, American Sniper without any sniping.

The BBC’s recent biopic of the Bloomsbury group, Life in Squares, had to thin out thirty years of history considerably to cover them in just three hours. Stripped of all unessential detail until only the bare bones of a plot remain, this drama is not so much a miniseries as a montage. Characters meet (invariably next to expensive paintings) and a minute and a half later are love. World War One lasts twenty minutes, or, by another chronological measure, three sex scenes. Imagine if To the Lighthouse were told at the same pace as its author’s life: the second line would be ‘Well, here we are then!’ Yet the silliest omission Life in Squares makes is required not for economy but for the reasons I’ve already mentioned. Not once do we see Virginia Woolf actually working. Viewers might be forgiven for thinking that she receives her novels in the past rather than writing them herself. Instead we do often see her sister Vanessa at work on her famous portraits. The show’s creators do not shy away from showing us her more camera-friendly art because they are more interested in entertaining us than accurately portraying their characters. In theory this is the right priority. They are producing prime time television, not writing a biography. But in practice their neglect of the truth is exactly what makes Life in Squares unsatisfying as a piece of entertainment, because we are simply not convinced the skittish, mumbling, apparently workshy character before us is Virginia Woolf.

For a writer to be believable on screen, we must be aware that there is an entire dimension of their personality which cannot be expressed in the visual medium – the part of themselves which they express in their prose. This is the second major difficulty of portraying writers on screen. Short of actually presenting the viewer with blocks of prose (as Bazz Lurhmann did in his Great Gatsby) film makers are prevented by their medium from showing us the writer’s work. Paraphrased or referenced or curtailed between quotation marks, it can only be glimpsed at, like the solitary thoughts which formed it. Woody Allen’s 1997 film Deconstructing Harry makes an almost successful attempt to circumvent this problem – whenever characters refer to Harry Block’s stories, the stories themselves are dramatized, as if they were quotations within the larger text of the film. The problem with this form is that it suggests these dramatizations are themselves Harry’s stories, when really they are just verisimilitudes, translations into a foreign medium.

Two of the best portrayals of writers on film that I know of succeed because they acknowledge they cannot give us insight into their work. The first is perhaps a little obvious: The Shining, a film far more frightening in its first half, when we do not what thoughts are going through Jack Torrence’s head as he stares at his typewriter, than in its remainder. While we do not know for sure how bad his writer’s block is, and while we do not know that his insanity is printed on every page of his manuscript, Torrence is an unknown quantity to us, perhaps a murderer or perhaps just a man going through a very poorly timed and situated midlife crisis. He is like a shadow on the bedroom wall, which may or may not be that of an intruder. It is structurally convenient that Torrence writes just that one line over and over again. This line can be held up to the viewer as a symbol for the monotony of his thoughts, whereas no whole novel could be captured on camera to show us the vibrant mind that made it.

It is almost too obvious to be worth saying that the scariest films are those which play on our fear of the unknown. What makes The Shining superb is that the unknown element is not some outwardly terrifying thing, like the Grudge, ready to intrude into the protagonists’ lives. It is Torrence’s mind, already hiding in plain sight when the film begins. By making the viewer afraid of the fact they cannot fathom a writer’s mind beyond a certain depth, Kubrick celebrates this very unfathomability.

Listen Up Philip, Alex Ross Perry’s film about a moderately successful young novelist with a point to prove, is brilliant for the very reason that it refuses to congratulate Philip for being mysterious to the viewer. We hear a lot about how good Philip’s two novels are (mostly from Philip himself) but we never find out what they are actually about, or what they are trying to achieve artistically, or what insight into the human condition, if any, they convey. Perry might have exploited this blind spot in the viewer’s vision, and suggested that if only we could actually read Philip’s works we would understand him and forgive his callousness. But he does not do this. In fact his film seems always to be trying to ignore its hero, like a dinner party ruffled by a tub thumper. So often the camera doesn’t acknowledge Philip until he speaks, and when he announces to his long suffering girlfriend that he intends to spend the summer with his mentor Ike Zimmerman, the narrative does not follow him. It sticks with his girlfriend for the film’s entire middle section. These directorial conceits are brilliant because they refuse to grant Philip the mystique of the enigmatic artist, which he tries to effuse with his every sentence.

What do the The Shining and Listen Up Philip have in common? Not much, except main characters who we can believe are complicated enough to have their own thoughts to put down on paper, or at least try to. Two dimensional characters can usually pass themselves off as three dimensional. They can talk as if they had more to say, behave as if able to behave otherwise. But a two dimensional character cannot pass off as a writer. For if they cannot convince us they think, than how are we to believe they can write?