Theodore Zeldin, the prodigious historian, was a child prodigy. He is evasive about this, preferring to discuss the ideas thrown up like lava from the smoking crater of his new book, An Intimate History of Humanity. Zeldin's publisher hopes the book will, like Hawking's Brief History of Time, touch an autodidactic nerve, that people will buy it to demonstrate their desire to know and understand more. But will they read it? Zeldin is absolutely confident that they will. It was his own idea to sell the book in restaurants, so that people can browse through its 472 pages while waiting for friends to arrive. He hopes they will want to add it to their bill.

His previous works include a five- volume history of French passions and a fictional inquiry into happiness. He calls his latest book, which he took seven years to research and write, a new kind of history. 'I am trying to squeeze in the whole of human experience, and to make some sense of it.' He believes that historians have neglected ordinary people's feelings, tastes, fashions, passions, leisure and pleasure. He wants to make them part of history; to open up the intellectual world.

'I know enough about academics; I prefer to talk to people who are different from myself. I'm a wanderer, an eavesdropper and a conversationalist. People like talking about themselves, and I need talk to stimulate my ideas.'

Each chapter of the new book begins with a brief biography of a woman: mostly French, sometimes famous or successful, but more often unknown. 'Women talk about all those things which are becoming increasingly important, shifting our focus from the old masculine preoccupations of war and power to feelings and relationships. People are suffering from isolation, they want more than money, and I see this book as an antidote to the current staleness of political debate.'

Knowing that he was an infant prodigy, I ask about his childhood. 'I'm no good at fairy stories.' I insist: 'Just tell me the facts.' He sighs, resigns himself and begins.

'I was born on Mount Carmel, in Israel. A poetic place to be born - yes? My parents were Russian. My father was an engineer and a very brilliant mathematician; my mother was a dentist. He joined the British Colonial Service and went round improving the Empire.' He smiles.

Zeldin smiles a lot - usually at his own remarks. If he laughs, it is because he has been struck by a new idea. He is pretty disparaging about frivolity, 'an attempt to avoid the problems of the world by engaging in parody and humour and making light of things. People like that seem to have a nice time by avoiding things.' On then with the life story.

'My father moved out quite soon to Egypt, where he looked after a military railway, and I was sent to this luxurious boarding school in Cairo. It was a pleasant life. I've never had any really difficult times, which is remarkable, I suppose.'

His speech is precise, pedantic, clipped, with the faintest trace of an unidentifiable accent. He speaks in rills of perfectly articulated thought. Once launched, he goes on until interrupted, whereupon he stops at once. He listens when women speak - a rare quality in a man.

'I had girlfriends from a very early age - I've always liked the company of girls. My school must have been one of the first mixed boarding schools, though the girls were kept separately. I've never had difficulties with girls.' Never? 'Obviously one gets unhappy when one loses a girlfriend.' He gives the impression this has not happened often.

Was he really a child prodigy? 'I suppose I was. I could read by the time I was three. I was always three years younger than anyone else in my class. My first report said, 'He bestrides the school like a colossus.' It's quite interesting being a prodigy - having a youth with no time to be young. Jeremy Bentham said it makes you discover very late in life what youth is.

'I wrote my first book aged 12, a kind of anthropological work, and another, a history, when I was 18. Libraries were the love of my youth; reading ran in the family.' Today, Zeldin lives in a white, flat-roofed house with typical Thirties metal- framed windows, set amid a large garden on a hill outside Oxford. He bought it 20 years ago, and relates how the widow of the previous owner returned with her husband's ashes, requesting to be allowed to bury them in the garden where they had been so happy. A month later their daughter returned, bearing her mother's ashes.

I ask for the next instalment of his life. 'I left school at 15 and went to Birkbeck College in London, because it had no upper age limit and thus no lower one either, so I was at university with greyheads. It was absolutely delightful. I used to work from 9am till 10pm every day.' There are few books on the drawing- room shelves, but from time to time he jumps up and pulls out one of his his wife's to show me.

They met after he achieved his second First, this time at Oxford, where he read modern history at Christ Church before becoming a Fellow of St Antony's. He was a postgraduate - 'in my thirties, as far as I remember' - and she an undergraduate when they met at a party. Each instantly found the other remarkable, and they lived together for several years. 'You might ask why we decided to marry. Well, you know . . . no particular reason.' Parental pressure? 'No, but they were very happy. It made things easier at the golf club, perhaps.' A joke? No, he is not smiling.

Zeldin is hugely proud of his wife, Deirdre Wilson, who teaches at London University. The essence of a relationship, he says, is that it must every day seem worthwhile. 'The fact that we have no children makes it easier for us to separate, but also brings us closer emotionally.' How do they divide up the chores? 'We don't do the chores. As you can see, the house is a mess.' It looks in perfect order to me. 'I do most of the cooking - I don't follow recipes, I concoct things out of whatever ingredients I have.' From a celebrated foodie, this sounds unlikely, but again he is unsmiling.

So they live an austere life of conversation and work? 'You might say I live a Tolstoyan existence. I have my garden, and I feel completely surrounded by growing plants and wild life - all eating each other - so, yes, it is austere in the sense that a peasant's life is austere. But 10 minutes away I have Oxford; one hour away is the airport. But my main activity is trying to think.

'I greatly value my wife's contribution - as someone who is extremely clever and generous and good, and an enormous stimulus to me. I couldn't have written any of these books without her, although I've done all the work.'

Does he work all the time? 'I don't really ever stop, no. This morning I woke up at 4.30 and, bang, I found I had the answer to a question. You go to bed with a problem and wake up absolutely clear: you've got it. I don't really have holidays. I did take one day off earlier this year. I took my wife to Eastbourne to see Martina Navratilova play.'

It is easy to believe that he was a child prodigy: some area of everyday banality seems to be missing from his make-up. He is so loquacious, such a good listener, such a hard worker, such a devoted husband - yet he is an outsider, almost an alien. He lives in England, but has a passion for the French, who stop him in the street to discuss his ideas.

He thinks a lot about happiness, yet claims his life is incomplete, and anyway happiness is not a satisfactory ideal. An academic gadfly, an enigma, a polymath: Theodore Zeldin is all of these. And coming soon, at your favourite restaurant: An Intimate History of Humanity, by a man who stands on the sidelines but knows how to eat and how to listen.

'An Intimate History of Humanity' is published by Sinclair-Stevenson ( pounds 18.99).

(Photograph omitted)