There is a great deal to be said for living in a tip

Martin Gayford invokes the spirit of Picasso, van Gogh and Banksy to defend his own untidiness. The British should celebrate their tradition of mess and muddle 1 n 1864 a Talmudist named Jacob Saphir arrived at Cairo. He made his way to the district confusingly named 'Babylon' after a Roman fort. There he visited the ancient Synagogue of Ben Ezra, and after complex negotiations he gained access to the Geniza, or treasury. The keepers provided him with a ladder and he climbed up to the roof of a room, two and a half storeys high Wriggling through a hole, he landed on an enormous mound of parchment, papyrus and leather bindings.

He was sitting, as it later turned out, on the greatest archive surviving from any mediaeval society — letters, petitions, contracts, accounts. The Jews of Old Cairo had thrown nothing away because by tradition any document written in Hebrew letters or which might contain the name of God should be saved. Consequently, for centuries, all their documents piled up in this big room. And there they stayed. The effect — to compare great things with small — must have resembled the current condition of my desk and study floor. I too throw little away, and seldom file it either.

Tidiness is, by many people and in many cultures, regarded as a virtue in itself. Untidiness, conversely, is a vice which we who tend towards it try to hide, frantically attempting to order our normal domestic chaos when visitors threaten to call. But, if one considers the matter for a moment, it becomes obvious that there is a great deal — artistically, historically, and environmentally — to be said for living in a tip.

As any neat person will tell you, tidying means destruction. It involves ruthlessly discarding everything that it is not absolutely essential to keep. On occasion, that may mean destroying a valuable item, such as a work of art.

Tower Hamlets Council has decided to paint over graffiti paintings by the artist Banksy. 'Whilst some graffiti is considered to be art,' a spokesman conceded, 'we know that many of our residents think graffiti in areas where they live, such as local housing estates, is an eyesore.'

Almost simultaneously came the news that ten pieces by Banksy had fetched more than £500,000 at auction. A little later we learnt that Islington Council had already restored a Banksy painting on Martineau Road five times.

Of course, there is room for more than one opinion about Banksy — though he is one of the very few British artists to have made an international impact since the days of Hirst and co. in the 1990s. But we can all now agree, I think, that the landlord of the villa Pablo Picasso rented at Antibes in 1924 made the wrong call. As is related in the latest volume of John Richardson's biography, Picasso took over the villa's garage as a studio, and in a mood of creative exuberance, covered its walls in murals. The proprietor, evidently a costively minded type, was infuriated.

'Unswayed by Picasso's argument that his "fresco" was worth a lot of money, the owner insisted that the artist pay to have the wall restored to its original state.' That man's heirs must be far from delighted with his decision. If Picasso's painting was worth a lot in 1924, its value would be stratospherically higher in 2007 — tens of millions, at a guess. The market price of clean garage walls, on the other hand, has remained low.

It is wiser not to tidy up works of art. The Scottish illustrator A.J. Hartrick long remembered the afternoon when Vincent van Gogh called on him in his studio in Paris. The Dutchman, with a torrent of explanation and vigorous strokes of his pen, laid out a new composition he had in mind (but never in fact painted). Later, Hartrick fervently wished he had kept that piece of paper; at the time it probably seemed just litter.

Neatness and tidiness, what's more, tend to destroy a sense of time. That is the nub of the complaint by proponents of the picturesque against the tidying up of old buildings. John Ruskin and William Morris expended large quantities of ink while attempting to prevent their contemporaries from cleaning up, smartening, straightening and generally rebuilding the ancient edifices of Europe. They had some success. Without Ruskin's protests, St Mark's would have been completely reconstructed as a neater, duller, newer version of itself.

A few years ago I was a little disappointed on visiting the town of Meissen which, unlike nearby Dresden, was not razed to the ground and incinerated by the RAF. It is a perfectly preserved old German town, untouched during the neglectful years of the GDR. Since then, so much refurbishing and repainting has taken place that it no longer looks old. I missed an occasional whisker of vegetation on a roof, or smoke-stained wall.

Ecologically, also, we learn that kneejerk tidiness is not necessarily beneficial. A few months ago, the Royal Society for the Protection of Birds issued a warning about the damaging effect on wildlife of such orderly new garden features as decking and gravel. The ultimate neat-person's horticultural move, perhaps, is to pave over the space in the front of the house and park a car on it — so much trimmer than leaving it in the road. In contrast, a spokesman for the RSPB told the Daily Telegraph, 'Weeds can be good. Untidy gardening is not a bad thing. Nettles are excellent for caterpillars and butterflies. Traditional cottage gardens stay the same for 100 years.'

Quite so. Our luxuriantly overgrown, and quite small urban plot is home to half a dozen species of birds, several mammals — including squirrels and a hedgehog — plus frogs and toads. In contrast, many of the fields in the countryside around — hedgerows tom out, ponds filled it, insects exterminated — are virtually sterile. In his great History of the Countryside, Oliver Rackham inveighs against the pointless tidying up that farmers go in for, not for any sound agricultural reason, but just to make the land look neater. 'The blight of tidiness,' he writes, 'every year sweeps away something of beauty or meaning.'

Of course, tidiness is not necessarily malign. It is more that the two impulses — The World of Interiors calls the corresponding styles 'minimalism' and 'cluttered' — are like yin and yang. One inclines its devotees to file all their papers, as I do, in a mound on the floor; those of the opposite temperament line up their pens in a row.

It is the same with artist's studios. Some, Mondrian's for example, are as spick and span as laboratories. In others, such as Francis Bacon's, the visitor climbed over a midden of brushes, paper, paint, and heterogeneous junk. Who is to say which environment produces the better results?

My point is simply that slovenliness has its value. In fact, squalor is something we Brits do very well. It is basic to the only aesthetic notion ever invented within these shores: the Picturesque. This mode of landscape requires overgrown vegetation, decaying masonry, tumble-down walls, a touch of grime and decay, a few of the 'old rotten planks' and 'slimy posts' so beloved by John Constable. Foreigners come here, a wise Londoner once suggested to me, to see a tit of filth'. If the Prime Minister is sincerely interested in discovering the essence of Britishness, perhaps he should consider dirt and mess.