We are going to meet at the National Theatre, but Tom Stoppard phones the day before and suggests tea in Chelsea instead. It turns out that Trevor Nunn, the director of his trilogy, has more or less shooed him out of technical rehearsals. Pointless to be there, Nunn said, and Stoppard agreed. But even this brief exile makes him fretful.
"I phone up occasionally, like an anxious father ringing the maternity ward, and ask if there is any news. It's rather like having a baby, actually. I used to be very apprehensive and nervous [when a play opened]. Now I'm more curious. But I've spent a long time on this one, and I can tell from my dreams that I'm more anxious than I pretend: those dreams when you can't read the map, or the plane's leaving."
Voyage, the first part of The Coast of Utopia, went into preview two days later. Along with the two subsequent plays, Shipwreck and Salvage, it charts the lives of Russian revolutionaries and idealists in 19th-century Russia. Stoppard's chief protagonists, the anarchist Michael Bakunin and the revolutionary thinker Alexander Herzen, are the small men of history; elevated, like Rosencrantz and Guildenstern, from bit-part status to stardom in Stoppard's study of unattainable visions, messy lives and personal memories.
Stoppard, too, is a voyager. As Tomas Straussler, a Czech Jew, he was an infant refugee, shuffled off to Singapore, then on to India, before ending up in England with his mother, brother and a Kiplingesque stepfather acquired along the way. All four of his grandparents died in the Holocaust, and his father, Eugen, perished when his boat was blown up in 1942 as he followed his family to India.
Obviously, Stoppard's story of those who flee absolutist regimes ties into his experience. "It wasn't self-conscious, but how could it not be true? If I hadn't come here, where would I have been? If I hadn't left Czechoslovakia, I would have been dead. Instead, I was in England, which seemed to me to be the best possible country to have landed up in."
So maybe his trilogy is the key to the real Stoppard. But what that might be is far from clear. Profilers (and perhaps his recent biographer, Ira Nadel) generally declare him unknowable; then add to the fog by introducing the minor errata that infuriate him. "Where do these bloody things come from?" he demands. So, for the record, he was never bullied at Pocklington, his public school, though he disliked his schooldays, apart from cricket. He doesn't eat baked beans. Nor, despite the prominence of this anecdote in Stoppard folklore, did he suggest to Harold Pinter that, instead of lobbying to have the Comedy Theatre renamed in his honour, he should change his name to Harold Comedy. "That conversation never took place," he says.
At first meeting, it is hard to see why Stoppard is classified as so mysterious. He is young-looking for a man who has just reached retirement age - an event he barely noted. ("To be 64 is appalling, so what does it matter being 65?") He smokes quite a lot and has the pallid look of a rehearsal-room vigilist. The putty-coloured canvas shoes and fraying jacket suggest a man who shops infrequently and alone.
I expect some arrogance to cling to the nation's most revered living playwright, but his manners are impeccable. Perhaps he is clever enough to know that charm is a better hiding place than rudeness, but he seems genuinely pleasant. From the hotel balcony where we sit, he points out his flat: a big glass barn in a block by the Thames. "A rather cold-looking place, but it suits me very well. Without the river, it would be pointless. My desk faces the water, and I'm perfectly happy sitting there. I'm never lonely."
Maybe because Stoppard did not do A levels, or go to university, he sets no boundaries on his intellectual reach. The eclecticism of his subject matter, ranging from quantum physics and chaos theory to Russian and European history, suggests a vast attic of a mind. Conversely, any information extraneous to work and family seems simply to have been sieved out of his brain.
Stoppard began his career as a reporter in Bristol. On applying to the London Evening Standard, he was interviewed by the then editor, Charles Wintour, who said: "I gather you're interested in politics. Who is the Home Secretary?"
"Look," Stoppard replied, "I said I was interested. Not obsessed." Even that tepid fondness has waned. His admiration for Margaret Thatcher did not turn him into a Tory, but nor does Labour enthral him. "I've voted in every election; not always for the same political party and never with any degree of enthusiasm. One character in my play objects to 'government by slogan for the sake of power'." Does he agree with what sounds like a routine definition of Blairism? "How does one know? But the appearance is government for the sake of power through any means."
Even Stoppard's fascination with asylum and liberty, central themes of his trilogy and his life, does not tap into modern politics. We have a desultory conversation about immigration policy, before he says, almost pleadingly: "Look, I'm in an area that I'm not used to talking about or even thinking about for more than five minutes. I'm not directed there to the extent that a person should be. I live quite a blinkered existence; maybe because I actually work very hard. My outlook is narrow."
But insularity was also drilled into him by his mother, whom persecution had made self-protective and who loathed him writing or lobbying on human rights. "My ma would say: 'Tomas, don't you realise most people are happy in Czechoslovakia? They don't know they're living in this prison society you talk about.' Her attitude was: 'We've got to England. Don't make waves.' I was sorry she was upset, but I didn't take any notice."
Apolitical as Stoppard is, he seems - in the week before the new arts budget is announced - enraged by the government's parsimonious funding. The fate of the regions is "really depressing. Regional theatres can't afford to put on new writing as often as they did. I remember when it was of interest. Now, it's just a risk. That's a retrograde development which, I suppose, you could trace back to Mrs Thatcher, but I can't say Mr Blair has reversed it. They get cross if you say so. Because the Arts Council kitty goes up a bit and the National Theatre gets £12m, the feeling is that the arts should think themselves lucky and shut up.
"I don't want to be seen as trying to get theatre a bigger slice of the cake. It's about the view of life of those who provide the cake - what a culture or society is trying to be. When you go abroad, you feel that culture is integral, not a little treat for a day off. Here, we're always talking about art and society. Art is bloody society.
"The one thing that makes the current situation unforgivable is that one is talking about sums of money which are pitiful compared to the largesse of waste in public funding in every other area of life. Not just the Dome, though that does spring to mind. But there's always money available for a crisis in any other area.
"It comes back to lack of culture. They [the government] know that the state of the health service will lose them votes, whereas the state of the arts will not. It's not that they have a political philosophy and arrange their finances accordingly. It's entirely pragmatic; all to do with winning and keeping votes."
Delivering this denunciation startles Stoppard. "I've never done an interview like this in my life," he says. He means, I think, that interviewers always stick respectfully to his work, but also that he has never defined himself outside that context. "There are playwrights who live for political and social reality, but I tend to live for family and work."
Stoppard has never spoken about his private life, including two marriages, to Josie Ingle and Miriam Stoppard, and a relationship, apparently long finished, with the actress Felicity Kendal. But he is, for a disciple of omerta, quite an inquisitive interviewee. Am I married? How do I pronounce my surname? And, when I don't finish the afternoon tea he insists on buying: "A sparing eater, are you?"
He, in turn, talks fondly of his four sons. "My youngest is 28 this year - they're not boys any more; they're great, grown-up men." He sounds like a good father, but he seems unsure. "I haven't done that well at all times. Having a marriage break-up when you have a four-year-old and a one-year-old is not being a good father at all. I've just done the best I can in the circumstances I find myself in."
While this last thought is too cliched a summary of a life ever to satisfy the eulogists and demystifiers, it seems a fair assessment of Tom Stoppard's voyage.
Voyage previews at the National Theatre, followed by Shipwreck (8 July) and Salvage (19 July). The Coast of Utopia trilogy is part of the Barclays Olivier Theatre Season