'I don't care what people say,' he says. 'I have no control over it. I don't think about it. But metaphysical? Fine. Why not?'

Discussing central themes risks poisoning his consciousness, Auster seems to be saying. He wants to keep his literary ideas in a part of his mind where they don't need words but can still seep into his writing. The less devoted Auster readers might recognise this sense of meaning being just beyond reach at the end of one of his novels.

Auster has no qualms about such responses, always preferring readers who take thoughtful confusion from his work to those who try to make a point too fine. His 12 novels as well as poems, screenplays, memoirs, pop songs and translations may be often ambiguous, but they are exactly what he wanted to write and have made him one of the world's best-known literary figures.

'Luckily I don't have to describe my work, and I don't,' he says as he stirs a black coffee in a hotel in Adelaide. 'I just do what I feel I have to do. I know that when I look back at what I've done, all the books I've published, there's quite a range of tones and approaches to telling stories - from what you might call rather bizarre philosophical novels to low-to-the-ground realistic novels, to absolutely fantastical, almost mythological tales, something like Mr Vertigo.

'Some books have a much more sombre tone than others. Some are quite comical,' he says. 'I'm trying to express all my contradictions in my books, the different sides of me, and not censor myself.'

The only concern he has about his ideas is that they keep coming. Auster says he rarely takes notes before starting a novel. Apart from jotting down a list of events or places he expects the story to visit, all of a novel is in his head.

'Often novels will sit inside me for years before I actually sit down and write. It mostly has to do with characters. I get a sense of who they are and what they're capable of and then the stories seem to coalesce around them,' he says.

'I can think about something for two years or five years or 10 years and then I sit down - I feel I'm ready to begin the book - and then everything I thought I was going to write goes out the window. Things occur to me and the book becomes another book, without exception.

'I've never started something that ended up the way I thought it would.'

The ideas for almost all of Auster's work come to him as sounds or voices - suggestions out there somewhere beyond words. If the voices harass him long enough he grants them an audience.

'If it won't leave your mind, if it won't let you alone, if it has you by the throat, if it's throwing around the room all the time, you have to get up and try to do battle with it to understand what's going on,' he says.

'A lot of ideas flit through your head and then disappear. But the ones that stick are sticking there for a reason and you have to find out what that reason is and then do something about it.

'I used to have many [voices and sounds]. Now I just have one or two, if any. I spent many years drawing on inspirations from early in my life, ideas that I eventually wanted to do. But now I'm in a new phase, what we might call the Blank World phase,' he says.

The phase - let's avoid saying it has anything to do with his dotage - started with the 2007 novel Travels in the Scriptorium, the story of Mr Blank. This character - elderly - has no memory of why he is kept in a small room with sparse, though comfortable, furniture, a handful of photographs of people he feels he should recognise and an unfinished manuscript. Characters from previous Auster novels barge in to check on him, provide information, food and sex. Is he a captive, or at home in the perfect writer's studio? Auster won't answer whether the short novel is about the creative process. All he knows, he says, is that the book had to be written.

'Travels in the Scriptorium started in a way that no other book of mine ever started. This time I saw a picture and it wouldn't leave me. For weeks I kept seeing this image, which was, quite simply, the first image of the novel: an old man dressed in pyjamas, sitting on the edge of a bed, with his hands on his knees, slippers on his feet, looking down at the floor. I had no idea what this meant. But it kept coming back, kept coming back and eventually I said to myself: I think I need to explore what's going on here.

'I came to a radical and perhaps erroneous conclusion that perhaps that man was me about 20 years from now. That revelation, whether true or false, unleashed the novel I wrote,' Auster says.

The image of Mr Blank remained in his head as he launched into his new novel, Man in the Dark. A 72-year-old grandfather - 'who's not young but not as old as Mr Blank' - lies awake, unable to sleep, for the first two-thirds of the story. In the final act he lies in the dark discussing the world with his 23-year-old granddaughter.

'I think it's a response to Travels in the Scriptorium,' he says. 'It's also short. Travels takes place in one day. Man in the Dark takes place in one night. My character is very sharp. He's flooded with memories. He's thinking about the past and he's making up stories in order not to think about the past.

'The book is largely about war - war in Iraq but other wars as well. It's not really about September 11. It's about the war that followed. It's not a political tract in any way. It's a very personal book. It becomes very intimate and personal. So you have this deep family story in the middle of this political story and eventually it comes together.

'I feel that I did the book I wanted to do. Whether other people respond to it is something I can't control.'

Auster says he has started 'groping' with his next novel. He has stuck with his deliberately slow process of writing in notepads. His often ordinary prose style is exactly what he wants.

'I rewrite everything a thousand times. It takes me a long time to write a paragraph. I write everything by hand in notebooks; because I rewrite so much it becomes really illegible.

'So when I have a paragraph that's more or less finished, or more or less acceptable, I type it up on a little 90-volt typewriter. Then I can see it on the page, cleanly, and then I can start attacking the typescript and rewrite that several times.'

He wrote one screenplay on a computer but now refuses to use the internet. He claims to have no e-mail address, let alone a mobile phone.

'I'm just not good enough at it to be able to control a computer. Your hand slips, you push the wrong button and suddenly all kinds of crazy things are happening.

'The good thing about a typewriter is it's absolutely silent. It just sits there, waiting, waiting, and then when you're ready there's that very pleasing sound of the roller, the paper going in, and the very pleasant sound of the clackety-clack of the keys,' he says.

'It doesn't give you carpal tunnel syndrome either, because you're actually striking keys and using your muscles in a way that builds them up. Whereas I think that the touch is so light on computers that it can be very damaging to your hands.'

We remind Auster that this sounds like the stubbornness of an ageing man. He's done nothing but talk about codgers who haunt him until he writes about them and the fear that such visions will dry up. Did we mention that his wife, Siri Hustvedt, recently released the novel The Sorrows of An American, about two middle-aged siblings pondering their father's life in the months after his funeral?

It can't be a stretch to say the Auster household is spending some time pondering - as non-verbally as you like - the twilight years.

'Well, Siri's novel is not about death and ageing. She's exploring a father's life, but it's not so much about the father's illness as much as the father's past,' he says, mild tetchiness returning.

'In my case it's a little different. As my British editor at Faber likes to say, I've been writing about debilitated men for the last few books. I suppose there's some truth to it.'

Writer's notes

Name: Paul Auster

Born: February 3, 1947, in Newark, New Jersey

Lives: Brooklyn

Genre: no-go area

Works:

Fiction: The New York Trilogy, In the Country of Last Things, Moon Palace, The Music of Chance, Leviathan, Mr Vertigo, Timbuktu, The Book of Illusions, Oracle Night, The Brooklyn Follies, Travels in the Scriptorium, Man in the Dark

Poetry: Disappearances

Screenplays: The Music of Chance, Smoke, Blue in the Face, Lulu on the Bridge, The Inner Life of Martin Frost

Essays, memoirs, autobiography: The Invention of Solitude, The Art of Hunger, The Red Notebook, Hand to Mouth

What the papers say:

'When [Auster's] novels work, it's because he successfully persuades us of the writer's oldest trick: that his characters have somehow broken free of their creator. They may be make-believe, products of a playful ideology, but they feel real and their feelings matter. In [Travels in the Scriptorium], this never happens, which makes it hard to care.' - The New York Times

Author's bookshelf

Don Quixote by Miguel de Cervantes 'I re-read it every 10 years or so. It's the novel of novels, in which every question about fiction is addressed. It's actually the first postmodern novel as well. It's an extraordinary feat.'

The Complete Essays of Michel de Montaigne 'I read him when I was an undergraduate. He's the first person to explore the individual consciousness. He's the first modern man and a great writer on top of it, with a dazzling, incisive prose style.'

The Scarlet Letter by Nathaniel Hawthorne 'Hawthorne is my comrade, my father in American literature.

The Great Gatsby by F. Scott Fitzgerald 'My favourite novel of the 20th century.'

The Collected Stories of Franz Kafka 'Kafka has always been very close to me. I haven't read him much lately, but he's inside me.'