The real Van Gogh: The artist and his letters

An exhibition of Van Gogh's letters with a selection of his works is a great success, says Tom Lubbock. But why can't we just let the paintings speak for themselves?

An advert for an art book club once asked: "How would you have reacted to Van Gogh if you had met him? Yes, you would have thrilled to his paintings. But would you have seen this mixed up man as saintly – or squalid? Like the citizens of Arles would you have jeered at him? Or would you have been one of the few who offered him friendship? Why not discover the real Van Gogh by inviting him into your home?"

The real Van Gogh? His art never seems to be quite enough. With almost any art there's a tendency to poke around behind the scenes. The work is only a clue. The life and soul are the story we want. But Van Gogh is especially susceptible to this treatment. His pictures are signs of his madness, a key to his sufferings and struggles. So often he's been brought forward as someone to pity or hero-worship or both – a modern martyr.

You could make a nice little anthology of Van Gogh-ology. There'd be the minstrelsy of Don Maclean, of course, and his "Starry, Starry Night". "Now I think I know what you tried to say to me / How you suffered for your sanity / How you tried to set them free / They would not listen, they're not listening still / Perhaps they never will..."

You'd have the poet Antonin Artaud, too, and his raging monologue, "Van Gogh: the Man Suicided by Society". And you'd have a most unwelcome guest, in the person of Joseph Goebbels, offering a rather similar portrait of the artist. "Van Gogh's life tells us even more than his work. He combines in his personality the most important elements: he is teacher, preacher, fanatic, prophet – mad. In the last analysis we are all mad if we have an idea." Whatever happens in the auction houses, Van Gogh – the real Van Gogh – remains for many the ultimate holy, crazy outsider.

The Real Van Gogh: The Artist and his Letters opens at the Royal Academy on Saturday. It's a marvellous exhibition. How could it be otherwise? Almost any gathering of Van Gogh's paintings and drawings will amaze. It's still astonishing how much he produced in less than ten years, and how much of that, even from the start, was original and exact. But no exhibition is content simply to show. It must tell us too.

This one has a firm agenda. It marks the new full edition of the artist's famous letters, published in English by Thames and Hudson. 15 years of scholarship, six volumes, 2000 pages, 4000 illustrations, £400 to buy, it's an epic production, and it offers to curators a new key. Demythologisation is their theme. Van Gogh's art was not in any way a symptom of his madness. It was not even the spontaneous overflow of his powerful feelings. It was a thoroughly deliberated and self-conscious enterprise, worked out in his letters, executed on canvas and paper. Where possible, corresponding manuscripts and pictures are displayed alongside.

Van Gogh's behaviour, they concede, "was inappropriate at times, and he suffered from what could be called mental derangement, but his output of letters and pictures displays a strong internal cohesion. This double oeuvre cannot be dismissed as the product of a sick mind. On the contrary, it can only be seen as the legacy of a truly great intellect: the real Van Gogh."

Now I must confess here that I did not spend the last month reading those six volumes. I don't have them on my shelf. Perhaps I never will. And if we're going to play "I haven't read", I may as well admit that I have read very little of these letters in any translation, even though people always say that they're terribly good. I'm not quite sure why not: perhaps a fear that in those letters I'd meet a man or an artist who would get in the way of the pictures.

This new version doesn't allay that fear. The scholar-curators may dispel the image of the artist-as-madman. Fine. But they replace it with something equally discouraging: the artist-as-prof. It's often said that we reconstruct the great ones in our own images. Here we meet a Van Gogh who is engaged in a steady and sober course of research, where explaining words and experimental images go in tandem. His work is the art historian's dream, a body of visuals that comes with its own verbal commentary. Or maybe something more radical still is proposed: an inherently two-fold project, in which pictures and letters become a conjoined-twin creation.

But frankly, and granted my shameful ignorance, I don't believe it. The letters are separate and secondary. If in some impossible hypothetical extremity you were forced between wiping out any or all of the pictures, and any or all of the letters, it's obvious – isn't it? – that without a second's hesitation you would decide to save the pictures.

On the other hand, if you choose to make the letters and pictures into collaborators, then the words – especially since they are the artist's own words – are likely to become the primary voice. They will tell you authoritatively what the pictures show and say. The language of the pictures themselves will be submerged. More than that, we take the pictures as objects to be interpreted. But really they are models from which we should learn.

Throughout Van Gogh's short working life, his art exhibits two broad tendencies. They're both present from the start. One you could call iconic, the other exploratory. One imposes shape, designs, patterns on the world. The other responds and is constantly flexible. Both of them show ways of living in the world. Both are very intense. One of them is a bit madder than the other.

The iconic works are generally the more famous. Vincent's Chair, Gauguin's Chair, the Cypresses of June 1889, The Postman, La Berceuse – these things and creatures are defined as cut-out forms with jerky edges. The images make sure of their subjects. They infuse force into these figures but at the same time they keep hold of them. There is implied a conflict between the self and the world. Sometimes the subject is reduced only to neat design.

The exploratory works approach the world quite differently. The clearest contrast is between the famous Sunflowers (still in the National Gallery down the road) and the Two Cut Sunflowers showing here. Sunflowers is comparatively a static cartoon, pinning down the flowers. In Two Cut Sunflowers the paint wants to know all about the structure, the texture, the energies of these organisms.

But the exploratory tendency shows most strongly in the landscapes and particularly in the ink drawings. Look at the Landscape Near Montmajour with Train – look, or rather participate in its activity. The terrain is translated into a vocabulary of pen-notations. The various areas of ground are mapped into various marks – dashes, dots, commas, loops, zigzags – set down with density or openness, modulating from one texture to another, so that the definition of a code is mixed with the flow of nature. The train puffing in the middle of the countryside is both startling and quite natural.

Works like this are miracles. In their clarity and certainty they look plotted, but their complexity and flexibility could only be achieved spontaneously. Every stroke is without doubt, and every stroke is a surprise. The mind, the eye, the hand, are continually improvising and always coming right. Vincent draws how one might wish to live. And it's these inexhaustible, exemplary, encouraging pictures that are the real Van Gogh: that's to say, his irreplaceable gift to the world.

The Real Van Gogh: The Artist and His Letters, Royal Academy, London W1 (0844 209 1919) Saturday to 18 April