'People asked how I dare kill God. If they looked closely, they would see that what is dying is an old idea of God as an ancient man with a white beard in the sky. What I'm criticising is not the Christian religion, but the tendency in human beings to excuse their behaviour by reference to some absolute.'
In a sense, Pullman's anti-Christian views are a red herring. His universe, a dark and dangerous place in which children are stripped quickly of their innocence, seems
founded less on dogma than on his own early years. It was a strange childhood from which few people could have escaped unscathed.
The one stable figure was his grandfather, an old-fashioned Norfolk clergyman who brought up Philip and his younger brother, Francis, and told them magical stories.
Although the boys also travelled the world as their father, Alfred, an RAF pilot, moved from one posting to the next, they spent little time with either parent.
Audrey, Philip's mother, based herself in London, working for the BBC, living a socialite's life and occasionally having her sons to stay at her studio flat in Chelsea. She was, by chance, with them in Norfolk when a telegram arrived from the Air Ministry to say that Alfred Pullman was dead.
'I was seven, and I hardly knew him. Whenever he had dropped in, his visits seemed exciting and fun. He had the glamour of being a pilot and doing manly things like smoking cigarettes and drinking beer.
'He was killed during the Mau Mau emergency in Kenya. I don't know what he was doing, but he was awarded the Distinguished Flying Cross posthumously, so we were allowed to think he had been shot down in action.
'Anyway, my mother was a widow, and we were nearly orphans. At the time, it seemed exciting. My father's dying meant that he was unaltered. He was going to be glamorous for ever. I was free to invent him, you see, free to invent the figure he might have been.'
At Buckingham Palace, Philip watched his mother collect the bravery medal, unaware that her role as the grieving widow was as artificial as his own glorification of a stranger he could not mourn. Soon afterwards, Audrey married her dead husband's friend and fellow pilot, John Dodgson.
Many years later, stumbling on a set of separation papers, Pullman realised that his parents had planned to divorce. Audrey, he surmised, had been having an affair with Dodgson long before the fatal air crash. 'Putting two and two together, I'm sure that is what happened. Not that it matters a bit.'
Audrey Pullman's second marriage, which produced two more children, sounds fraught and unhappy.
'My stepfather had had a difficult, bruising background himself, as a repressed public schoolboy who didn't get on with his parents. My mother and he didn't always get on, so there was a lot of tension in household. But they stuck together.
WHEN my mother died 12 years ago, Dad sort of broke out. He became a Buddhist, which was counter to everything he had done previously. It was as though he suddenly felt liberated. Then he had a series of small strokes and became immobile. His life was very sad in the end, really, but I loved him dearly.'
It is telling that Pullman's love, a word he uses sparingly, should be reserved for his stepfather - strange, damaged but undoubtedly the best parental figure he had.
When Dodgson died two years ago, Pullman commissioned a firework manufacturer to place his ashes in skyrockets which lit up the sky above the Firth of Forth.
For Audrey Pullman there had been no such effusive send-off. 'Poor old Mum. She was a very clever woman who never got the chance to use her intelligence. There was always something unfulfilled and frustrating about her.'
Did he love her? 'She was difficult,' he says. 'When she was kind, she was very kind, and when she was bad she was bonkers; a very nervy, stressed sort of woman.
'By the time of her death, she seemed happy. She died in her sleep, very suddenly, so everything was all right in the end.'
Audrey bequeathed to her elder son her belief that he was a failure. 'I'd published a few books, but she didn't think much of them.'
Pullman shrugs off such criticism. The only sign of any toll taken by the past is his preference for the dullest life he can devise. He writes every morning in a large workroom where he also keeps machine tools for his joinery, walks his pugs and watches Neighbours.
He and Jude, a former hypnotherapist, have two sons, Jamie, 32, a viola player, and Tom, 22, a linguistics student at Cambridge, as well as a baby grandson, Freddie.
But despite his taste for tranquillity, Pullman is also driven by great furies. Though he has been an informal adviser to the Education Secretary, Charles Clarke, the Government's emphasis on tests, targets and a rigid curriculum appals him.
'I would sooner go out in the wind and rain and dig potatoes out of the ground with my bare hands than be a teacher now,' he says.
If Philip Pullman's work endures, it will be a testament not only to talent but also to his ability to use to his advantage whatever unacknowledged pain still lingers of a difficult childhood.
Since childhood, he seems, in his own mind, to have turned his inadequate parents into storybook figures.
Rather in the manner of the God he so despises, he has recreated as glamorous spirits two people who could have wrecked a small child's life. That fiction, I suspect, has been his mechanism for keeping his own dark forces at bay.
The Ruby In The Smoke, the first book in The Sally Lockhart Quartet by Philip Pullman, has recently been published by Scholastic Children's Books, price £5.99.
