But Middle England is elusive. Its coordinates are vague, its exact psychological and demographic conditions largely undefined. You can aim at pinning it down with a formula like "middle class, middle brow and middle aged", but with every shot the target seems to move. For Middle England is as much a state of mind as anything else - a collection of attitudes that shift with bewildering stealth. You cannot map Middle England, nor expose it to the usual tests of social chromatography: you merely feel it, as Sir David did. And even he got it wrong sometimes, expecting a harsher reaction to a particular news event than actually existed out there.
Out there is the only location we have for Middle England. There is a similar idea in the United States where all the decision-makers in government, entertainment and finance inhabit the great coastal cities. When a Madison Avenue advertising executive or a Washington politician ask how a campaign is doing "out there", they mean Middle America, an expression, incidentally, first used in 1968 to describe Richard Nixon's heartland supporters. Middle America is literally the geographic centre but also serves as shorthand for the silent majority and a range of conventional values and tastes.
Middle England is more difficult because it is both rural and urban, although not - I am certain - metropolitan. It is frustratingly hard to describe it simply in terms of class, income and race. For instance, many Asian businessmen have joined Middle England and subscribe to 90 per cent of its tenets. The same is true of other races, and also of Anglo-Saxons who have migrated from different social classes to find meaning and constancy in this old attitudinal territory.
My own understanding of Middle England comes from Professor Michael Oakeshott who wrote about British conservatism with great insight. He said: "The disposition to be conservative is, then, warm and positive in respect of enjoyment and correspondingly cool and critical in respect of change and innovation. These two inclinations support and elucidate each other. The man of conservative temperament believes that a known good is not lightly to be exchanged for an unknown better. He is not in love with what is dangerous and difficult ; he is unadventurous ... What others identify as timidity, he recognises in himself as rational prudence."
That, I think, more or less captures Middle England. For it is conservative and it tends to value the past, while regarding the future with a wary eye. Things have changed, however, on the margins of Middle England. The members of the post-war generation, which rebelled and experimented in the Sixties and Seventies, have entered middle age and many find themselves installed - sometimes unconsciously - in the grouping they once loathed. With them they brought convictions from the permissive decades which now account for Middle England's greater tolerance of homosexuality, single mothers and sex before marriage. I don't say this is a complete tolerance by any means, but it is there.
So Middle England moves one or two steps behind the times. The important thing is that attitudes do shift gradually. If they didn't, Middle England would simply fade and become a redundant secular sect. Sometimes they move with a spurt that catches out the psephologists, market researchers and editors of national newspapers. For instance, it is fair to say that the people who once would not hear the slightest criticism of the Royal Family now entertain ideas of a reduced role for the Windsors. The same shift may be occurring on constitutional matters, although it is difficult to gauge. The modernisers should be careful: if they go too far Middle England will turn on the government, as it did in the countryside movement.
Perhaps we are simply describing a conservative section of the ever- expanding middle class. But no. Imagine two neighbouring middle-class couples, Family A and Family B. Both have incomes of over pounds 45,000 per annum, both own their homes, shop at Tesco and run similar models of hatchback. But there is still an important difference between them. Whereas Family A remains detached from the community and lives for its excursions to Spain and Florida, Family B is a little whirlwind of activity. Mrs B is a member of the Parent Teacher Association and a prison visitor. She recycles her waste and keeps her old magazines for the local health centre. Her husband is a member of the Rotary and golf clubs and occasionally goes to rugby internationals at Twickenham. Neither is particularly cultured, although Mrs B reads when she has time - Joanna Trollope, Ruth Rendell and volumes of memoirs. Mr B always votes Conservative, but Mrs B liked the look of Tony Blair and agonised over her decision last time, eventually voting for the Liberal Democrats. She did not tell her husband.
The important things that separate Mr and Mrs Middle England from their neighbours are the vigour, variety and constancy of their lives; but most of all they are bound to the community with numerous ties of duty. They have a sense of obligation - in all probability inherited from their parents - and a good deal of what goes on in their area depends on them giving freely of their time. If you take England as whole, the work that this social grouping does is really quite remarkable. The fetes, bazaars, horticultural shows, charity car boot sales and marathons for kidney machines and scanners raise enormous amounts of money, but they also serve to fill Middle England's calendar with fixtures which give reassurance that things never change. This need helps to explain the strength of its tribal gatherings and if you want to see Middle England on display you have only to visit the Chelsea Flower Show, Crufts, the Cheltenham literary festival and the Chichester theatre festival. At the arts festivals you will find Middle England engaged, though sometimes puzzled, by the avant garde.
Another characteristic of Middle England is its deep reservation about new fads. Modern passions for therapy and counselling are regarded sceptically and the confessions of celebrities that fill the features pages of the national newspapers make Middle England shudder. As a general rule, Middle Englanders prize stoicism and shun self-pity. About the media, they are extremely sceptical and are apt to blame it for the ills of the country. It is perhaps worth mentioning that it is impossible for someone to belong to the media and to Middle England, for it is an important part of the latter's condition to feel disenfranchised by newspapers and television. The Daily Telegraph, Daily Mail and Radio 4 are of course considered allies, but allies that sometimes err. The Internet, meanwhile, is obviously a worthless American invention.
Middle England's conservatism is at once intensely frustrating and reassuring. It provides a kind of marrow to English life which is responsible in turn for a great reservoir of political stability. This is an influence out of all proportion to Middle England's actual size for it has nothing like the relative weight of Middle America in the life of the US. What it does possess is a genius for organisation. The skills learnt in running the annual fete or other charity events may very occasionally be mobilised into big displays of discontent. Again one thinks of the countryside movement.
It is very little understood that Middle England relies heavily on the energy and views of women. I have no solid evidence for it, but I suspect that the slight movements of attitude which are registered in Middle England are first promoted by women. It will be Mrs Middle England who tries alternative medicine, who makes friends with the Indian couple that have moved into the village shop, who suggests that when her son returns from university with his steady girlfriend, they be allowed to sleep together. Her husband goes along with these innovations grudgingly and later comes to accept them.
Does Middle England exist outside England? Certainly there are branches in other parts of the Union where exactly the same sturdy and stoic middle- class values are to be found, but it is essentially an English phenomenon and I cannot think of its equivalent on the Continent. Middle England has many faults: it is mistrustful, simplistic, sentimental, mildly xenophobic and anti-intellectual. But these all constitute the flip side of its supreme virtues of decency and engagement. The one thing you can be sure of is that Middle England has none of the docility of the newly enriched mass market. And for that we should be thankful.