INTERVIEW / Mistress of morality tales: P D James: Jan Dalley meets the celebrated crime writer whose latest novel examines evil from a very different perspective

'I ALWAYS give the same answers,' P D James told one of her many interviewers. 'They don't change if you tell the truth.'

It was a remark that sums up a lot about Baroness James of Holland Park. She uses unfashionable words like 'truth' and 'moral responsibility' quite unselfconsciously, and there is a quality about her which makes her listener accept them in the same way. And she has been, over the years since her celebrated crime novels began to attract huge attention, extraordinarily consistent: always a comfortable, rational, beautifully mannered person, who is as good and dutiful as an interviewee as she seems to be in other departments of her life. With infinite courtesy and patience she will answer (for what must be the thousandth time) that question about why middle-class British ladies are so good at grisly murder (yes, perhaps it is a rechannelling of sublimated aggression, but you know, my dear, it's probably more to do with a keen eye for domestic detail). And that other question, about her remarkable catalogue of public service: for many years a London magistrate, chairman of the Society of Authors, a governor of the BBC, until this year chairman of the literature panel at the Arts Council, chairman of the British Council, a member of the Liturgical Commission of the Church of England, and, since early 1991, a peeress with a seat in the House of Lords. She is a believer in public duty (another unfashionable concept), and feels it particularly important that women should say yes to public appointments, and carry them out well (and adds, but with humour, that she thinks she gets asked to do these things because she doesn't make trouble - 'Men, of course, can be as troublesome as they like'.)

It is a heavy load, and she only finds time to write between six and eight in the morning. This continues an old habit, begun during the painful years when she was married to a doctor with the romantic name of Connor Bantry White, who came home from the war with a mental illness which meant that Phyllis had to support both of them, and her two young daughters.

Everyone, everyone, likes her. Younger writers in the genre - the Crown Princesses of crime - speak of her 'tremendous, genuine kindness'. Everyone notices that she calls them 'my dear', and then that her charm is underlaid by a hint of the steeliness to be found in the books. It is the same steeliness, presumably, that got her up at six in the mornings to produce her first novel, Cover Her Face, before catching the train to a heavy job in the Home Office (in forensics and criminal law, appropriately) and taking evening classes to get promotion.

She went on to write 12 more books, and in 1987 was awarded the Crime Writers' Association's Diamond Dagger for her lifetime's achievement. Today, at 72, her toughness is concealed behind a slightly mumsy persona, but there are flashes of a darker underside; in the ordered calm of her Holland Park house, furnished in the epitome of intelligent, middle-class good taste, she will suddenly mention that when she visited St Barnabas' Church in Oxford she immediately 'saw' a couple of corpses on the floor with their throats cut, or that when walking along the Purbeck coast, on a visit to her daughter's new parents-in-law, she visualised a wheelchair hurtling over the cliff and smashing on the black rocks below.

These two moments resulted in the plots of A Taste for Death and The Black Tower respectively, but they make you wonder how many other such visions there must have been. The only outward clue to this imaginative abyss is that, as we talked in her sitting-room in a respectable London street in the middle of the day, with other people in the house, the front door was carefully double-locked (and relocked after each delivery, each arrival) with a bunch of keys hung always around her neck. P D James is a very good person; she is also very, very interested in evil.

A healthy belief in evil is probably indispensable for a good crime writer. The enduring popularity of detective stories is because, she believes, that 'in an age when murder is so often random, the crime novel is a comforting form - it reassures us of the sanctity of life (if you get violently killed, someone will care) and of the fact that we live in a comprehensible, rational world, a world in which human authority, and human skill and integrity (the detective, the police), can put things to rights'. Criminal law is a passionate interest of hers: she sees it as the construction of 'fragile bridges of safety, of order, over the chasm of psychological disorder'. It is hard not to read echoes of her experiences with Connor Bantry White in this obsession with the forces of turbulence.

More than in random chaos, though, P D James is interested in moral choice. She sees detective novels as 'in some sense the equivalent of the old morality plays': for this reason, she has no interest in stories about psychopathic killers. 'Their motivation is not like that of the rest of us.' And her new novel, The Children of Men, is an even more intricate forum for discussing human motivation, moral responsibility, the essence of good and evil.

SOMETIME in 1995, a midwife in a busy London maternity unit suddenly notices that the pages of her appointment book, usually crammed, are empty. There are no appointments, because there are no pregnant women. All over the world, suddenly and simultaneously, the human race has become infertile: it is known as Year Omega.

This is the idea on which The Children of Men is based; the book opens some 25 years later, in an England that has had to come to terms with an ageing, unrenewable population and the terror of a silent future. By 2021, a dictatorship controls a panicking population and ensures comfort, security and pleasure. But one small group, which calls itself the Five Fishes, dares to challenge this absolute authority.

No murder? No Adam Dalgleish? 'It wasn't a deliberate decision to change course,' she says. 'I love writing detective stories, and I will again. But this idea came to me so strongly, I had to write it straight away.' Its genesis was a newspaper article which reported that human fertility in the West had fallen dramatically in the last 20 years, for no apparent reason; shortly afterwards, she read that the majority of life forms that have existed on the planet have died out. 'And I thought - suppose it happened to human beings, suddenly, all in one year? What kind of world would it be? What would it mean for the way people lived, their motivation? It is almost unimaginable, what it might do to human beings.'

Only afterwards, she says, did she realise quite how many accepted ideas were thrown into question by her premise. The novel - 'I suppose it is a sort of moral fable; I don't like to describe it as science fiction' - discusses how authority is exercised, and what it is that makes us act as we do. Without the motivation provided by the future, she believes, order would break down: why do anything that is not utterly selfish, if there is no one to plan for, and no one to judge us?

This is millennium talk, of course, showing the author's distaste for the society she lives in, and a longing for redemption. She describes her imaginary future as 'a very bleak picture'. A sense of divine punishment for our sins hangs heavy over the book: it is unfashionably Christian. Two of the rebellious Five Fishes are practising Christians, and the unthinkable, the miraculous, happens to them. 'I wouldn't be satisfied to think of it as a purely Christian novel, though. What restores the world is love, commitment to another human being . . . But of course Christianity is the religion of love, despite its effects in the world, which have often been the opposite.'

Lady James's belief, like that of any intelligent person, is a complicated one, but her love for the traditional liturgy is straightforward. In this book, its echoes seem almost to have a potency of their own. In one extraordinary scene, the two Christians give each other Communion over a makeshift altar in a wood; it is, its author agrees, like an ancient fertility rite: God made flesh. In the past P D James has written about the liturgy with great passion, as when, in the Independent Magazine, she chose as her hero Thomas Cranmer, author of 'that incomparable liturgy, now so neglected, that for generations has nourished, inspired, exhorted, rebuked and comforted Christian people in these islands . . . and, with its robust, underestimated clarity about the truth of the human condition, still has the power to speak to us today'.

'Clarity about the truth of the human condition' is what her new novel is seeking, and in the end it seems not so much a departure from her other work as an extension of it. What is new, though, is that pragmatism has gone. 'The crime novel,' she says, 'is an essentially unsentimental form.' But as her books have evolved (becoming much more sophisticated, less formulaic), she has conveyed the reality of violent death with increasing truthfulness, and the justice of her solutions becomes more incomplete, messier, more realistic. At the end of the new novel, there is no offering to the God of justice: it's in His hands anyway, P D James seems to be saying; who knows what He will do? Next time, though, Commander Dalgleish will be back.

(Photograph omitted)