For Professor Hobsbawm is not a terrier historian, worrying away at one moment or place. Neither is he the eclectic citizen chronicler of the kind that Simon Schama is now popularising. He is the historian of the grand sweep. His major works, starting with the Age of Revolution and extending to last year's Age of Extremes, are masterpieces of synopsis and observation. Everything since 1789 has now come under his gaze: the toppled king, the doomed peasant, the poet and the merchant.
I'm here to get a VE Day antidote. Yes, the party was great; those Forties costumes, Vera Lynn - all that Britishness. But standing back, how much is nostalgia and how much fact? And after the party, what happened then, what went wrong with victorious Britain? It is time for the cooler look - the view from Hobsbawm.
His handshake is firm and friendly, not the limp finger-press of the bored celebrity. At the age of 77, he is in good shape, with the slight stoop of the scholar. The house itself is pleasant and unfussy - the grand historian is not a grand man. We talk in the large front room. It is a kibbitzer's room. Half the books on the shelves are about jazz and American music. The colourful pictures are from India and the Far East. On top of the coffee table are typed notes in German, with handwritten annotation. Hobsbawm inhabits the real world, not the stucco and parchment academic universe of some of the Oxbridge historians.
He presses his fingers together. Yes, celebration was in order. "The end of the war was not simply a triumph over a foreign enemy, but a moment of hope - a mood of confidence in social change that was enormously strong. This was so powerful that even the post-war governments of the right had to take account of it."
He itemises the concessions made to socialism by the post-war administrations of France, Italy and other countries. "Until 1949 the Christian Democrat party said that they did not think that capitalism had a future in Germany!" And he believes that ordinary Russians, too, expected change - "an end to tyranny and terror" - but were to be disappointed.
Hobsbawm speaks in a steady stream. He is as precise in his generalisations as accountants are with their figures. Each one is linked to some specific example. The professor would be a great man to have on your side in a pub quiz. I find myself wondering if anyone has patented Untrivial Pursuits.
First question - to win a green triangle - how did Britain lose the peace? Hobsbawm is fascinated by the answer, since Britain entered the post-war period with some big advantages: "The extraordinary business is how everybody, including the Labour Party, underestimated the real crisis, the weakness of the British economy. We came out of the war, relatively speaking, stronger than anybody else on the continent. The others were lying flat on the ground. For five years we looked much stronger than before."
Only gradually did the penny drop: "It wasn't until the Sixties that it began to penetrate that there was something basically wrong with the British economy. Look at Tony Crosland's books in the Fifties. They assumed that there was no problem with the productivity of the economy. Sympathetic foreigners could recognise it."
He leafs through a book, produced from under the coffee table, and finds the quote he is looking for. It is from Michael Brady, an American economist, writing in 1950. Brady, who liked Britain, castigated the failure of the British establishment to appreciate the scale of the country's decline. "On the available evidence," he wrote, "Britain only needs a Gibbon to write a chronicle." "You see," says Hobsbawm, "foreigners could see that there was something wrong, except the British people didn't want to see it. Not until the Sixties did it become a serious issue."
Until now there has been a slight wariness between us. Since the flood of reform that washed away the Soviet Union, former members of the Communist party (I am one of them) - no matter how independent-minded they are - always wonder on what part of the ideological beach other ex-members have been washed up. Are they now Blairites, or has the tide carried them all the way to Newt Gingrich-land?
Hobsbawm must also know what a risk he has taken in writing about his own times. He was a participant during an era of political passion, and critics see in his history the signs of attachment to a political position, no matter how coolly expressed. And it is true that the excesses of our side - the left - are perhaps more easily (if more painfully) explained than those of the enemy. Hobsbawm's partially submerged preference has led some historians to charge him with being too gloomy about the world's prospects in the wake of the welcome given to the collapse of Communism.
He does think some of the best parts of the post-war legacy - social reforms in education and welfare, the anti-fascist alliance - are now being left behind. "It is inevitable, the generation which experienced war, or the conditions of the Thirties, has gradually by sheer age and death been eliminated from politics. In all countries it is of enormous importance when the people who themselves had no memory of those days became leaders of their countries." The post-war settlement is crumbling. "The great stability of Western liberal capitalism in the period after 1945 has ended. We have entered a different period in which the possibilities of maintaining welfare states and national macro-economic management on the level of the nation state are eroded - and the scope of national political control of the conditions of life in a particular country have been very much diminished."
This diminution of the economic power of the nation state does not make Professor Hobsbawm a committed European federalist. It is a matter of force majeure, not preference. "As for the common values in Europe, I'm very sceptical. One of the reasons why we've had a European Community is because most European states are too weak now to maintain themselves as independent national powers and so - in self-defence - they've had to get together. So let's say we all ought to stick together in Europe, but do not let us believe that there is no difference between people from Sicily and Ummia in Sweden and people from the Peloponnese and those from Kerry."
Incongruously, when the phone rings and it turns out to be an Italian woman calling about arrangements for a trip to the Turin book fair, Hobsbawm does not hesitate. He moves instantly from one idiom to the other, his Italian fluent and lacking the operatic affectation that sometimes mars English speakers of the language.
When he returns to the sofa, he is not optimistic about the future. The values of the past four decades are everywhere assailed. "The political stability based on the belief in democratic parliamentary systems has largely disappeared. You can see that in a large number of countries today the political systems are - in the case of the United States - on the verge of breaking down, and in the case of France and Italy, experiencing a sharp break with the past."
Most to be feared, says Hobsbawm, is a resurgence of those forces whose defeat we celebrated so recently. "The major threat these days is a right wing based on nationalist, religious or similar chauvinism or identity politics. On the other hand the resources for fighting these new threats are less." Why less? "Because one of the major resources in the period before the war and during the war were strong, self-confident labour movements. These are now weakened. A lot of their former support has, in fact, become a potential constituency of the far-right. One of the most depressing statistics I have seen lately is the recent French presidential elections, where 31 per cent of the unemployed voted for the National Front - the highest percentage of any party support among the unemployed." There is real regret here about what has happened to the working class. He goes on: "The old class movements and unions were not only schools of genuine values of civilisation, but of citizenship. Without them the potential for fighting these new passionate and negative ideologies has become less. I think this is going to be one of the major problems for the next 20 or 30 years for the politics of men and women of good will."
He smiles. If he does expose his background sometimes in his writing, at least you know where he comes from. And he is certainly a man of good will. That helps when he stands next to you on the hill and tries to describe the landscape below.