Is the Shard really 'worse than the Taliban'? Piano tells me the Shard is designed to "flirt with the sun. When it's finally complete and the windows are fitted with blinds, these will rise and fall automatically with the sun. London has a far more mobile sky than Paris or Genoa and, so, there will always be this play between the tower and the elements. And when the clouds descend or fogs envelope the building like a cockney "peasouper"? "That will be beautiful too, in its way," says Piano. The tower will look like pewter sharing the sad face of the city until the sun comes out again, and it smiles. It would, of course, be disappointing to pay £25 for a ride to The View only to come face to face with fog, especially, as many critics have said, the money to build the skyscraper in the deepest recession since the Thirties has come from foreigners. Arab oil billionaires to boot. "So, what?" asks Piano. Does money from London smell so sweetly of roses? Does money from the Qatari royal family have a bad perfume? The Shard is a response to changes in London, its architecture a witness to those changes. What matters, as architects, is that we try our best to make new buildings, for a new reality, something special. Sir Simon Jenkins, chairman of the National Trust, is not convinced. "There are plenty of places," he has written, "for Sellar [Irvine Sellar, Sixties Carnaby Street boutique owner turned 21st-century property magnate] and Piano to play their games. Why must they tip paint over my Canaletto? In the mid-18th century, the Venetian artist Canaletto lived in London and painted exquisite views of the city from the Thames. Apparently realistic, they were beautiful carnival masks concealing the true nature of a city at once thrilling and vile. Since the 1750s, the face of London has metamorphosed many times. Views along the Thames from Battersea to Beckton have long been pockmarked by rashes of grim and even savage buildings, tall since the early Sixties when Harold Macmillan's Conservative government did away with height restrictions. London's contemporary riverscape looks nothing like a Canaletto, nor even the view from Westminster Bridge evoked by William Wordsworth 60 years before Underground trains first steamed beneath city streets: The beauty of the morning: silent, bare, Ships, towers, domes, theatres, and temples lie Open unto the fields, and to the sky, All bright and glittering in the smokeless air. Change, sometimes for better, sometimes for worse, has been a part of the city's restless character since Boadicea led her revolt against the Romans and torched the city that the commercially minded invaders had only just founded on the banks of the Thames, nearly 2,000 years ago. Sitting on the deck of the Nellie, a cruising yawl anchored east of London, Charlie Marlow, the principal character of Joseph Conrad's Heart of Darkness, published in 1902, looks along the river. The sun set, the dusk fell on the stream, and lights began to appear along the shore... and farther west on the upper reaches the place of the monstrous town was still marked ominously on the sky, a brooding gloom in sunshine, a lurid glare under the stars. "And this also," said Marlow suddenly, "has been one of the dark places of the earth." " The horror. The gorblimey horror. And, yet, one critic's horror is another architect's, or artist's, delight. The accusation that Sellar and Piano have tipped paint over a Canaletto recalls the court case of Whistler v Ruskin. In 1877, the celebrated critic John Ruskin published an attack of a painting on show at the Grosvenor Gallery by the American-born artist James Whistler. "I have seen, and heard, much of cockney impudence before now," railed Ruskin, "but never expected to hear a coxcomb ask 200 guineas for flinging a pot of paint in the public's face." Whistler sued for libel and was awarded a farthing in damages. Curiously, when I stare at images of Whistler's compelling Nocturne in Black and Gold - the Falling Rocket [the original hangs in the Detroit Institute of Arts], I see something akin to the look of a high-rise city lit up at night. Perhaps it's my eyes, yet this thrilling vision is a strangely beautiful one, and a sight that can be experienced from high windows in Hong Kong across from Kowloon or indeed, today, across night-time London from the Shard. Back on the ground, the real problem I feel with the new London skyline is the depths to which architectural design and urban planning have descended. The criticism - hurled against Piano like the spears of Ancient Britons fighting the civilised Romans - is, I think, a bottled up attack on our low standards of design and the beetle-browed politics that have allowed so many poor tall buildings to have been rushed up around St Paul's. The Shard, whatever its flaws - and all its many floors - is a much better building than most of the flakes below it. Those booking tickets for the ride to The View on the 68th to 72nd floors might be interested to know that when it was announced in 2000, Piano and Sellar's tower was to be much taller. The Civil Aviation Authority, however, decreed that 1,400ft was too high, a danger to low-flying aircraft. Earlier this month, a helicopter hit a crane in Vauxhall, a few miles west along the south bank of the Thames. It dropped into the street. The pilot and a passer-by were killed. That crane was employed to complete The Tower at St George's Wharf, a priapic 50-floor block, and the highest residential building in Britain. Otherwise known as "Prescott's P----" - it was approved by John Prescott when he was deputy prime minister in 2005 - this is one of the very buildings that makes anyone with the slightest love of London weep with shame. How low can high-rise get? How tragic? On a sunny day, though, when the Shard is "flirting with the sun," the City and Southwark will look a billion Qatari dollars, Piano's skyscraper hoving into view above the Thames smelling of some new, if startling, variety of city rose. The View from the Shard, London SE1, opens on Friday 1 February. (theviewfromtheshard.com)