Most English people live in cities. The largest 10 urban areas, as officially defined, contain 18.3 million people – the urban areas of London, Manchester, West Midlands, West Yorkshire, Tyneside, Liverpool, Nottingham, Sheffield, Bristol and Brighton. Some of these urban areas are quite arbitrarily divided, separating Sheffield from Chesterfield or Liverpool from Birkenhead, so the 40 per cent of the English population which seems to live in the 10 largest urban areas is probably an underestimate. And substantial towns mop up most of the rest of the population – a major town like Salisbury, with 50,000 inhabitants, is only the 167th largest town in the UK.

Cities are by far the most convenient way the human race has found to live. There is a range of opportunities for individuals. Competition works most efficiently in a large city. There is a large choice of social, cultural and economic opportunities. There may be some trade-offs – the pressure of crowds, the limitations on space for living in, the cost of accommodation often rising as individuals press into a successful city. But most of us find opportunities greatest and our futures most full of potential in an urban setting. They are where our futures lie.

For that reason above all, our anxiety about the countryside seems to increase the more we are separated from it. A small skirmish, earlier this year, showed just how anxious we town-dwellers can get when the countryside comes into question. The Government proposed that the national forests, administered by the Forestry Commission, should be moved into private hands. There was no question of closing off access. The Forestry Commission's taste for miles and miles of boring conifers has always been much criticised. And some of the nation's most treasured forest symbols, such as Ashdown Forest in East Sussex, on which AA Milne's Hundred Acre Wood was based, have always been privately owned. Nevertheless, the question of change coming to the country seemed unacceptable to an unlikely alliance of interested parties, curious observers, and people living in third-floor flats in SW7. The plans were dropped.

The Government is proposing to make development easier by a root-and-branch revision of planning laws. The draft National Planning Policy Framework, published in July, is trying to simplify the planning process, and to create a framework which is, in general terms, in favour of sustainable development. The planning policy is not directed explicitly towards developments in rural areas, but, as so often in this country, the issues surrounding it have been directed by rural interests.

In particular, a new presumption in favour of development over community objections has been interpreted by Friends of the Earth and others as "a way for developers to build on [open land] by demonstrating the need for and benefits of their development". Some people might think that if a developer can demonstrate clear need for, and benefits of a development, then that might be an important factor. Is there any need in the eyes of Friends of the Earth that would justify a development on open land? I rather doubt it.

A Canadian architect once asked me if London was still growing, geographically. Like most English people, I guess, I found the question frankly bizarre. Of course, English cities have reached the edge of their geographical limits and are now only growing in population terms. The fact that the situation strikes us as inevitable and beyond question is part of the problem. There is no justification that most of us can see for allowing our cities and towns to start growing beyond their 1960s limits.

It is rightly pointed out that developments on open land are not the only solution. Brownfield development has been a useful standby over the last years. As a Rowntree Foundation report pointed out last year, brownfield development has risen to provide, in 2008, 80 per cent of new housing development. It is also pointed out that there are nearly three-quarters of a million empty homes, forcing property values up and increasing scarcity. Those are important factors, but they can't be the only solution. If any politically palatable solution could be found for those empty houses, it probably would have emerged by now. It's not only wrong to suggest that no open land in this country should ever be built on, but it shows a lack of understanding of where the value of the countryside comes from in the first place.

What we are talking about, when we discuss the countryside, are not really the wild spaces of England. The national parks are preserved, and so, effectively, are the great estates which will never be built on. Tastes change in these matters – Charles James Fox, in the 18th century, admired Chatsworth for standing in "wild and desert places – to step from dreariness into splendid apartments". We now greatly admire that dreariness, and no-one would touch it. What are at stake are those parts of the country which, in fact, have been historically much developed and cultivated. It is deeply curious that the National Trust is so strongly campaigning against these proposals that it is encouraging every one of its members to write to their MPs. Surely, the National Trust exists mainly to preserve beautiful, historic houses and their land – often, radical rethinkings of landscape at the time. Is it really saying that no beautiful or thoughtful development on open land could ever take place in our own age?

It is true that, through experience, we have come to the conclusion that most newly-built houses in the country are an abomination. But it need not be so. Think, for instance, of the magical building Michael Hopkins built for the David Mellor factory in Derbyshire. It is modern, fresh, tactful and much loved by locals. Why, we may ask, does the planning process not enable more buildings of this high quality rather than act as a process to block any development at all?

For a millennium, the English countryside has been groomed, developed and cultivated into an image of sophisticated rurality. It is, largely, an illusion. Thoughtful intervention has tended to survive. What are we leaving to future ages? The presumption against development in the planning process is wrong. What is needed is not no development, but more, and better quality, development.