Graphix

Thirty-five years ago I bought a dilapidated house in North Kensington, London. One of the reasons I bought it was that it sported a magnificent graffito. In those days, graffiti were usually texts, some of them, it was said, written by the poet Christopher Logue. This one spelt out, in foot-high block capitals, the undeniable truth that "Boredom is counter-revolutionary". When the house was done up, the graffito disappeared. Over the years, the neighbourhood lost all its graffiti one by one, as the pestiferous warren of flats and bedsits was regentrified. The wall that had the one word "Scream" written its full length was repainted, and the grim prediction "This too will burn" was removed from a pillar under the Westway.

Aerosol art is not the same thing at all. Although Banksy is as likely to be arrested as the defacers of those days, what he does is jokey, wry, fundamentally civilised. In a message that's been sloshed up by a couple of four-inch brushes loaded with red and black gloss paint rather than sprayed through a stencil, you see not good humour and self-deprecation, but honest-to-goodness grief and rage.

For months I thought about restoring my graffito, maybe cleaning the new cream stone-textured paint from off the letters or even painting them again; but eventually I realised that for the owner of a house to scribble on it is just pathetic and downright disrespectful, like Foxtons the estate agent having the name Foxtons painted on the side of its fleet of Minis in graffito script. You've got to be working full-tilt, hanging head downward off a motorway bridge with your mates holding you by the feet, writing . . . what? Probably your tag in blocky letters outlined in contrasting trim. Nearly all graffiti are just annoying, but you have to put up with the millions of naff ones if you want the occasional brilliant one. A great graffito is not simply an arresting design; it is a once-in-a-lifetime coincidence of work, place and space. Would anyone now dare to sandblast the murals of loyalists and republicans from the walls of Belfast? Now old IRA wall paintings are being touched up and recycled with messages in Arabic signifying solidarity for the Palestinians. And Banksy has done his best work on the West Bank Barrier.

Most aerosol art, like most other art, is feeble and bad. If bad art was a crime, some of our most respected citizens would have been banged up years ago. Wall art, whether brilliant or ordinary, is a crime so serious that it is to be treated with zero tolerance: fortunes are spent in tackling the graffiti scourge; in Berlin low-flying aircraft are used to scan the streets with infra-red cameras to catch the spray painters at work. Oceans of highly toxic solvents are being sluiced over walls and hoardings to wash the paint into the sewers and eventually into the water table. Wildly illiberal proposals are coming from all quarters: possession of spray paint and selling of spray paint will become crimes; taggers will have their driving licences withdrawn and be fined huge amounts on the spot. In England two young men known in art as Krek and Mers, who haven't done a graffito in two years, have been sent to prison for 12 months and 15 months respectively - though one of them was due to start an art course at university, his mother had offered to pay for the damage, and 500 people signed a Facebook petition. Needless to say, making an example of them will be the opposite of a deterrent; tagging is now heroic protest. Expect to see the names Krek and Mers on every railway bridge.

Graffiti cost Londoners £100m a year, and the country as a whole more than a billion, we are told; what is actually costing is not the art, which is free, but its destruction. The engine driving this colossal expenditure is Encams, mastermind of the Keep Britain Tidy Campaign, which implores us not to drop litter or chewing gum, dump cars or rubbish, make lots of noise, or leave our dogs' shit on the pavement. Major mess-makers they leave well alone. Apparently graffiti and fly-posting can fill people with a feeling of unease or fear, because they associate both with crime. As fear of crime is already way out of proportion to the actual incidence of crime, loathing of graffiti must be equally, if not more irrational. We should not pander to it.

Walls don't look much better after their graffiti have been washed off than they did before, so we might as well stop doing it. In environmental terms, the washing-off makes a worse mess than the painting ever did. The wall-painters themselves will paint over each other's work, especially if they consider it feeble. A far less costly option is for us all to make our own stencils giving the defacers marks out of 10, to remind the artists that there are people out there who have eyes to see, and as much right to say what they think as the artists. The work then becomes a palimpsest, a dialogue between artists and public. Most tags deserve the single-word comment "prat".

Whether at Lascaux 17,000 years ago or in Western Arnhem Land 50,000 years ago, art began on a wall. If the sandblasters had been around in either place, we would have lost a precious inheritance.