In Westminster Cathedral, two communities circulate. Under the bright light and deep gloom of the vast windows and darkling arches, the aisles and chapels are busy in a way other churches and cathedrals are not. Worshippers and tourists criss-cross. It is almost immediately obvious which is which. The reverent are lighting candles, staring at side-altars, muttering devotions; often they have brought their worries along, clearly lined into their faces. The rest are so absorbed with the glittering neo-Byzantine inlaid walls, arches, apses and domes, they do not see the true religious life of the cathedral around them. Each passes the other as if in different realms. 

To find so much real religious activity inside a church you would probably have to go to St Mary Abchurch in the City, an orthodox church which is packed out on Sundays with families gathered at the back, trestle tables full of food and drink, children playing and drawing, parents chatting through the sermon, young men dipping outside to smoke. It is only in places like this that you can get close to the sense of what church and cathedral life used to be. Not all of history is as orderly and precise as the neat Georgian and neoclassical remains which much of central London has to offer. In many places, we can still find the fascinating mess of real life.

What’s so absorbing about Westminster Cathedral is the mingling of activity. A churchwatcher picks his teeth. Old ladies in colourful jackets walk careful along the aisles, as they would in supermarkets. The elderly, clattering on sticks, greet each other like neighbours. All stripes of person are seated in the nave: gossiping, reading their catechism, hands folded in prayer. Painted nails match well with the decor here. Outside, men in Salvation Army caps buy fruit from a grocer’s stall; a homeless man sleeps on the pavement, undisturbed by the noisy traffic; a man wearing a Big Issue vest has no copies left. 

The law of diminishing returns soon kicks in

All along the main road, the buildings are made of flat fronted glass. The polychromatic brickwork of the Cathedral pops out in angles between the streets and above the fray. This contrast of neat and messy continues as you wend your way through the side streets of Westminster: Lewisham Street, Dartmouth Street, Cockpit Steps. In this way you will see the crush and clutter of tall and short, old and new, flat and ornate. Hawksmoor’s great west towers on Westminster Abbey will come in and out of view, never quite complete. What a change it makes to come out onto Birdcage Walk. Here we have the plain, expansive order of Horseguards, the Treasury, St James Park. Now London’s twists and turns are gone. Now we have long avenues, grand curves, the long sweep of power and the stout stones of government. Avenues of trees are evenly spread through the park. Here, there are vistas.

In the first London, we have the accumulated genius of many generations and alterations. In the second, we have the unifying vision of John Nash. Nash designed central London’s formal layout, including St James’ Park, Regent Street, Buckingham Palace and Regent’s Park. He also designed Trafalgar Square. In this part of London, his influence always tells. We owe him a lot. In St James Park, standing on the bridge over the lake, you get one of London’s best views. But this mode of design creates large places where no-one ever really looks at anything for its own sake. Once a system has been put in place, organic development becomes more difficult. Regent Street might be impressive in its own way, but the law of diminishing returns soon kicks in, and the overall effect is sometimes quite dull.

Does anyone ever go to Trafalgar Square just to see it? It might be loved for what it represents, a symbol, a patriotic place, a tourist attraction, those marvellous Landseer lions on Nelson’s column. But does it really hold that much inherent aesthetic appeal? Do you ever wake up and feel like you have to go there just to look at it? It’s important, but is it attractive? It is all the rivulets and tributaries around it that hold the charm. 

What Nash really bequeathed us is a sort of neat-freak approach to city planning. The City has mostly been free of this organising spirit. After the Great Fire, Wren wanted to rebuild it all in orderly fashion, somewhat like Versailles. The City decided to stop expensive architects having fanciful ideas and get on with putting it all back how it was before. Hence, we are left with something very much like the old mediaeval street patterns. The endless reinvention of the City ensures vitality round every corner. By far the dullest part of the City is the junction at the Bank of England, where the formal layout did succeed. John Nash and his planful approach, you see, is overrated.

Canary Wharf is magnificent; Victoria Street is hell

This distinction between the messy and the neat, the organic and the planned, helps us understand why London so often dislikes modern buildings. Modern architecture is often plain, clean, formal — it disrupts and diminishes London’s brouhaha of shapes and styles. Richard Rogers Lloyds Building is popular despite its ugliness because it revived the hyper baroque of Hawksmoore and Archer. Buildings like the cheesegrater get no such fondness because they try and impose Nash’s neatness where it is not needed. The van de Rohe-style glass fronts of modern buildings have the same dispiriting effect. It’s wonderful when you put it all together; it is horrible when it interlopes and spreads into otherwise variegated places to the extent that it chokes off other styles. Canary Wharf is magnificent; Victoria Street is hell. We no more want a London that is all Trafalgar Square and no Garlick Hill than we would enjoy demolishing everything ornate and giving it all the appearance of a sheet of graph paper.

See Paternoster Square, which has the aesthetic of an out-of-town retail park. Ivy Lane was demolished for this. And right next to St Pauls! It’s one thing when grands projets give you the South Bank, entire of itself, but to go pulling down London’s narrowing alleyways for a banal pseudo-plaza is just in bad taste. 

Banality is the true problem with modernism. The giant skyscrapers of glass are glorious. The mid-level imposition of flat fronts is dull, ideological and flat. Systematising London was what gave us buildings like Admiralty Arch, a candidate for demolition if ever there was one. Like Buckingham Palace, it’s not a bad building, but it’s hardly a great one. What stops us knocking down things like that, as much as the deep instinctive preservation of British culture, is the fear that a big glass block will take its place. The main expectation the anti-modernist public has is that architects will impose this banality on them. The sooner they stop, the sooner we might be able to build more. And build the architecture of the future.

For inspiration, go and see the Sainsbury Wing of the National Gallery, easily the best part of that building. It starts with the same columns and cornicing as the original, then slowly fades to modernism as the building curves, leaving a refreshingly plain space with enjoyable decorations on the railings below, creating perhaps the only surface in Trafalgar Square that isn’t attention seeking. It has a stark and lonely feeling inside, but the façade is a remarkable success. Robert Venturi, the architect, said the pilasters, which were copied from the Gallery but all clustered before they fade away, create a complex jazz rhythm compared to the gavotte of the original. The side is glass, which is not facing the Square and provides good light for the stairs. It is an imaginative use of classical and modern ideas. Let’s have more of that, and less Nash modernism.