"We hold these truths to be self-evident, that all men are created equal; that they are endowed by their Creator with certain unalienable rights; that among these are life, liberty and the pursuit of happiness." Even now, Thomas Jefferson's words from the Declaration of Independence have the power to move. Whatever the United States has become since 1776, it's always a good idea to remember that in its origins it was a revolution. And of those "unalienable rights", the cheerful endorsement of the pursuit of happiness is, surprisingly, the one which has had the widest social and psychological impact.
Ancient institutions have crumbled under this pressure, most obviously marriage, but also some others which seemed impregnable, such as the Anglican and Roman Catholic churches. Would Thomas Cranmer or the Venerable Bede have had the faintest idea what a "happy-clappy" service could be about? When happiness is added to the trio of faith, hope and charity, the balance is disrupted: three's company, four's a crowd.
At the atheistic end of the scale, Soviet communism collapsed because people were bored rigid. All those miles of cornfields and ballet in the evening - to quote Peter Sellers' leftist shop steward in I'm All Right, Jack - were very well in their way, but give us blue jeans, email, rock chicks and a passport to the Costa Brava. (That overbuilt coastline has found a new market from beyond the former Iron Curtain.) As post-Soviet experience demonstrates, happiness is a slippery eel.
It seldom stays caught. But the polling firm YouGov boldly has set forth with its statistical fishing net. It tried to capture how happy the people feel who live in different parts of England. The "greatest concentration of very happy people" is in Cornwall and the Isles of Scilly, YouGov reported last week. Is this astonishing when the poll was commissioned for Cornwall Enterprise, a regional development agency? Also, it was conducted entirely among the middle classes.
Those below that social mark, in a county notorious for poor wages and (outside the tourist season) high unemployment, somehow escaped the net.
But let's not carp. Sun and sea are undoubtedly very nice, even though I somehow can't forget the wife I talked to who'd moved with her husband to Cornwall. "All there is, is church, golf and bridge, and I'm not interested in any of them." Maybe she's one maverick who has fled back to London. But YouGov hit the target when it put the south-east of England bottom of the happiness chart. The message from this section of the survey seems to be that money can't buy you happiness. Cue for song? According to the 2006 edition of the annual Social Trends, the top-earning segments of the UK are: west London (but not east); the rest of the south-east and east England; plus Edinburgh (because of its finance houses) and the West Midlands' ultra-bourgeois enclave, Solihull. The worst-earning place is Blackburn whose cotton mills are now a distant memory.
Like many towns on either side of the Pennines, Blackburn was happiest when tall factory chimneys were pouring out carbon pollution in all directions. "Where there's muck there's brass" was, historically speaking, true - and a better bet, long term, than call centres. As it happens, I grew up in a town like this. The school badge, embroidered in gold on blue, featured an Art Deco version of just such chimneys, complete with plumes of smoke. The problems - including racial ones - in many of these towns began when the dead chimneys were felled and two rival groups, brown-skinned and white, were tipped off into welfare dependency.
Lancashire and Yorkshire still outstrip the south-east in the new happiness survey. Perhaps the 19th century sceptic and cleric Sydney Smith was right: "Mankind are always happy for having been happy; so that if you make them happy now, you make them happy 20 years hence by the memory of it." Or maybe it's that, as many northerners think, middle-class southerners are just "a lot of miserable buggers". Let's delve deeper, though. Sociologists have spent many years - not all of them fruitful - trying to define what "poverty" means, when few people in a country like ours are poor on the old criterion: that is, without proper food or shelter. Many have decided that poverty has to be judged relatively - that is, you're poor in today's Britain if you fall behind the rest of your fellow citizens by an agreed (or sometimes arbitrary) percentage. Maybe the southerner's problem with happiness is similar. On any dispassionate scale, they're rolling in it. Higher incomes, warmer weather, better chances in the NHS postcode lottery, surrounded by greater tolerance: by March 2006, 238 same-sex civil partnership ceremonies had taken place in Westminster, 236 in Brighton, with only 36 in Newcastle-upon-Tyne.
But in London and the south, there are all too many Joneses, very visibly up there on the hill, living an even more luscious life. A survey by the Halifax, published yesterday, listed Elmbridge District, in Surrey, as the most lavish of such enviable places. Elmbridge includes the UK's richest private estate, St George's Hill, a favourite of rock stars and football players. Unhappiness - relative unhappiness - seeps in through the hole. The two things that struck me most strongly, when I first came to live in the south, were: (a) people were taller and looked better fed; (b) there were far more people whose income came from nebulous sources. These days (a) is a bit less true. But (b), with the rise in wealth, is even truer than it was then.
So no Utopia. But this may not be anything to weep over. Utopian writing always ends up portraying a place that nobody in their right mind, other than fanatics, would want to live in. You could say the same about the Islamist vision of a world run entirely on Sharia principles, with all non-believers massacred. Every Utopia, from Sir Thomas More (who invented the word) onwards, has to eliminate real people - sometimes with Stalinist or al-Qa'ida glee - in order to create an environment of compulsory happiness.
What would true happiness be? Does it include conflict? During wars, as sociologists have noted, suicide rates fall, as if a sense of common purpose helped. In the First World War, recruiters emphasised the merit of dying for one's country: dulce et decorum est pro patria mori. But not all wars evoke the same sentiments. No one in the British Army is recruiting for the Iraq or Afghan wars on this basis.
Happiness is awkward to institutionalise. Misery always creeps back in. Gerrard Winstanley created Leveller settlement in the middle of Surrey - ironically, on St George's Hill - during the English Civil War. He thought it would be a good start if all lawyers were executed. Money was to be abolished. Any slackness at work would be punished by slavery. The idea didn't catch on, somehow. All attempts at communes have had a poor history. Whether in the wilds of Wales or Wyoming, some doorstep dictator always ends up in charge.
We could look, instead, at people's real-life choices. To judge by recent news reports, happiness might include: an even faster web connection - the average British user apparently spends more than 50 days a year online; a cupboard full of shoes - half of all women are claimed to have more than 30 pairs; and, to cap it, a second home in Croatia, which some call the new Tuscany, others the new Costa del Sol.
The National Gallery's re-display, next month, of its modern masters will include a famous painting by Georges Seurat: bathers sitting in the sun on the banks of the Seine at Asnières. It looks like happiness to me. But is this what Thomas Jefferson had in mind?
Paul Barker is a senior research fellow at the Young Foundation