John Davies meets Mary Warnock, (right)philosopher and veteran of numerous committees of inquiry. Mary Warnock may have passed her 70th birthday, but she is still learning. "By nature I'm a perpetual undergraduate," she says as she sits in the tiny living-room of her London flat. "I've always been quite good at getting interested in whatever my next essay subject was, as it were. That was what I learned from doing Greats."

The Oxford-educated philosopher and former mistress of Girton College, Cambridge - her six-year tenure ended in 1991 - is talking about her life as a public figure. For more than 20 years, she has been included on many an advisory committee or committee of inquiry, on a variety of subjects from environmental pollution to euthanasia - indeed, her Who's Who entry notes four occasions when she has chaired such a body.

"I have always been capable of asking questions until I thought I knew the subject,'' says Baroness Warnock, whose name is probably indissolubly linked in the public mind with her chairmanship, in the early 1980s, of the committee of inquiry into human fertilisation and embryology. That committee, she recalls, included a "brilliant teacher", Anne McLaren (director of the Medical Research Council's Mammalian Development Unit) - "it was like having a second undergraduate career" - but Warnock now feels she is no longer up to date.

"The whole subject has changed to genetic manipulation and the human genome," she says. "The science is becoming more and more difficult, at least for me. I'm quite happy with embryos, but not too good about cells. So I find I'm called upon to give moral pronouncements on subjects I'm not really master of, and I don't like that at all."

ÖйúAƬ

Despite this, Warnock felt it necessary to speak on the matter in the House of Lords last year, when an amendment to the Criminal Justice Bill introduced a new clause to ban foetal tissue experiments. (She opposed it; it was defeated.) Her membership of the House of Lords goes back to 1985, when she was created Baroness Warnock of Weeke in the City of Winchester - her birthplace. She is an independent peer, but "I seem to have been a sort of honorary member of the Opposition benches for all these education bills. That could change though. Being an independent is a very agreeable position to be in. I needn't come to the Lords unless I'm interested.'' She lives in Wiltshire; the West London pied-a-terre is used only when duty and London call.

It is philosophy, however, rather than her public career that this interview is intended to be about. (Of course, there is a link; as Warnock notes in her 1992 collection of essays, The Uses of Philosophy, in both committee work and philosophy "dialogue or discussion is not accidentally but essentially the proper mode of advance"). We meet soon after the publication of her latest book, Imagination and Time. Not to be confused with her 1976 philosophical study, Imagination, the new book is based on her 1992 Gifford lectures at Glasgow University, and the Read-Tuckwell lecture at Bristol the same year. It is, she says, "the last philosophical book I'm going to write." Although it ranges widely, dealing with, for instance, story-telling and personal immortality as well as touching on epistemology, aesthetics and artificial intelligence, Imagination and Time has at its centre the argument that "imagination is crucial in the acceptance of shared and continuing values", to use a phrase in the final chapter.

ÖйúAƬ

"Yes, the message is in the last chapter," says its author. "There are masses of accumulated apparently different topics which come together in this message about values, which is what I do believe in. That's my style of lecturing: I go rampaging around and then just at the end there is this moral."

It may be the final philosophical message of her own, but Warnock has not yet bidden farewell to the subject. She is currently editing an anthology of women philosophers. Reading through her forerunners in the Bodleian, she says: "I've made the rather depressing but unsurprising discovery that most of the women who wrote before this century were terribly amateurish and slapdash." Nevertheless, she is pleased to have found the "absolutely wonderful" Anne Conway, the 17th-century metaphysical writer who may have had some influence on Leibnitz. "Her book (The Principles of the Most Ancient and Modern Philosophy) is barking mad sometimes . . . but it was regarded very seriously at the time."

Of course among the 20th-century philosophers anthologised is her former Oxford colleague Iris Murdoch, a copy of whose Metaphysics as a Guide to Morals lies on the coffee table in front of us as we talk. She was among a handful of women philosophers in the 1950s and 1960s, says Warnock, who "began to develop a rather different style of doing moral philosophy . . . I think they were more interested in the concrete and what it was like to feel a moral dilemma - all the things Sartre was good at doing through his stories."

Both Warnock and Murdoch have written books about Sartre and existentialism. Forty years ago, writing about ethics had, in Warnock's words, "come to a dead end". Books with titles like The Language of Morals seemed to look not at ethical problems themselves but at the way people talked about them. Warnock recalls her Oxford colleague Philippa Foot "was quite influential in making people think that there had to be some content in moral philosophy again". At the same time, ethics "was thought to be very easy and therefore suitable for a woman".

No doubt such thinking led Oxford University Press to ask Warnock to write her first book, Ethics Since 1900, which came out in 1960. Apparently the commission had been offered first to both Foot and Elizabeth Anscombe: "I was just the next person on the list." At the time, she was a fellow at St. Hugh's College, teaching all branches of philosophy: Oxford, she says did not encourage specialisation.

You were very conscious of the history of the subject (at Oxford). That was a very fruitful way of approaching philosophy for the general run-of-the-mill undergraduate. You could introduce them to what philosophy was like, but you could also get them to imagine how problems appeared to Descartes or Hume." This is a long way from today's specialisations in, for instance, medical ethics - "which is disastrous, because they lose all contact with the sources of their ideas".

Ethics Since 1900 was followed by Sartre (1963), Existentialist Ethics (1966) and Existentialism, but it was her 1976 book Imagination that gave her the most satisfaction - in fact, it is the only one of her 15 books that did not arise from a commission. "I felt as if all my life I'd been waiting to write that," she says now, "I was always terribly keen on Wordsworth and the Romantics, and as I went on doing philosophy I realised there were enormous links between Coleridge and Kant particularly." Indeed, in the preface to her new book, she remarks that "my interest in philosophy has always been an interest in the history of ideas"; Imagination and Time's index has more references to Wordsworth than to Wittgenstein.

Imagination, the earlier book, was written immediately after Warnock had given up her post as headmistress of Oxford High School for Girls. Though it was indeed a contribution to the history of ideas, it also had an educational message: that we should cultivate imagination, the "capacity in all human beings . . . to go beyond what is immediately in front of their noses". Imagination, she argued, "needs educating" - and this would be "an education not only of the intelligence, but, going along with it, of the feelings".

ÖйúAƬ

Warnock says she has never been a "tremendously committed academic'' and was "always keener on teaching than research", so her 1966 move from an Oxford college to a high school was not a problem. Besides, she had worked as a school teacher during a break from wartime Oxford, and "had always loved the whole atmosphere of school - it's so optimistic".

ÖйúAƬ

Indeed, it was her involvement in the local education system, as chairperson of the Oxfordshire schools' music subcommittee, that inspired Warnock to take charge of the school where two of her daughters were pupils already. Her proudest achievement in her six years there was its musical improvement.

Although the subject of music is strangely absent from her books on the imagination, it is indeed one of her passions: she grew up playing the flute (but "sold it in a moment of poverty") and was also persuaded to learn the viola at the insistence of her older sister, who wanted to form a string quartet. She learned the French horn, too, while headmistress - in order to encourage the girls to take it up.

Of the Warnock's five children, two are professional musicians - bassoonist son Felix helps run the Orchestra of the Age of Enlightenment and teaches at the Royal Academy of Music; daughter Fanny plays the cello.

It is for her family's sake that Warnock thinks that her next project might be to edit her diaries. Begun in 1941 - the only year missing is, alas, the momentous one of 1945 - the diaries would be an "embarrassment" for the Warnock children, she says, if nothing is done. "They won't know what the hell to do with all these things, so it would be better to edit them. It's also something I promised my friend Frances Partridge I would do.

"But it's a bad diary; it has too many different forms. Partly it's to remind me what date I put in the broad beans last year so I can look it up. That's very difficult to mix with one's beautiful thoughts."

Meanwhile, her husband, Geoffrey, is no longer active. He has fibrosing alveolitis, she explains, "a lung condition which makes it difficult to breathe. He doesn't exactly feel ill, but he can't do anything. He sits with his oxygen machine, so it's a bit gloomy. But he's a good person to suffer from the disease if anyone's got to because he does like reading, and he's very keen on sport on television. He's lazy as well."

Lazy or not, Sir Geoffrey Warnock has had a distinguished Oxford career himself. Fellow and tutor in philosophy at Brasenose and then Magdalen, he was principal of Hertford College for 17 years until 1988, and university vice chancellor for four of those years. It was his appointment as principal that contributed to his wife's leaving Oxford High School. "There was an awful lot of entertaining (at Hertford). We moved from North Oxford and lived absolutely bang in the middle of Oxford."

It was while he was fulfilling his duties as Oxford vice chancellor that his wife was a member of the Lindop Committee of Inquiry into the validation of public-sector ÖйúAƬ, which reported in 1984. Its recommendations were not, on the whole, taken up. "I'm afraid the handing out of the title of university to all comers has been a pretty awful move," she observes.

Perhaps as a result, she is pessimistic about ÖйúAƬ in Britain today."There is a widespread indifference to what universities provide. One can't say it's all the fault of Margaret Thatcher, but it's a Thatcher culture. It's becoming so unattractive now for a student to go to university that quite soon it will slip into a culture that thinks only fools go to university. If you want to get on, you get into the job market right away and make as much money as you can. The role model is Richard Branson, I should think. I admire him very much, actually, but it's a sad way to go."

So what can be done? "I don't see how ÖйúAƬ can improve at the moment. There's so little money that it's going to take some sort of extraordinary revolution to get back to anything like we were in the 1960s, and I don't see where that revolution can come from. I do feel very gloomy about it.

"Having virtually always been connected with universities, one did feel that one was part of something that was terribly important, and that would never go away. I just don't feel that any more, which is sad.

ÖйúAƬ

"In my worst nightmares I think we've got to go through a kind of dark ages, when all the libraries shut and nobody reads and there are no more publishing houses except for pornography. We've got somehow to get through all that before there's a renaissance."