As a second-year student at Oxford, aged 19, I switched from history to PPP (philosophy, psychology and physiology) and my tutor, Elizabeth Anscombe, who didnt hold with political philosophy, said: Right, I will send you to Mary Warnock! So I spent a month with Mary having tutorials, writing essays and reading books by Hobbes, Locke, Rousseau and Marx. She was 16 years older than me, a mother of five and a fellow of St Hughs College. I used to bicycle up there and wed have some really good conversations. I was struck by how fun and jolly she was.

Mary was modest and practical and a very good listener. For her, it was always about the substance of the conversation. Ego really wasnt her thing.

After that, I didnt see her again for a long time. In 1966, she became headmistress of Oxford High School for girls, which is a very striking thing for an academic who really loves her subject, and wrote more than 20 books on it, to take on. Later, she went back into the university world. Her career was constrained, not in any way that she resented, by the fact that her husband, Geoffrey Warnock, was also a prominent philosopher, who later became vice chancellor of Oxford University, so she felt that he needed quite a lot of support, and I suspect some of her moves and reversals reflected that.

There are many people who would not be alive today, but for the approach it took to IVF

The next I became aware of Mary was when she chaired the Committee of Inquiry into Human Fertilisation and Embryology in the 1980s. Its difficult now to remember how fraught this was. The key moral issue in many peoples minds was that the early embryo is a person, so you cant be complicit in its destruction. But its not very easy to see how you do IVF without first doing the experimental work, and then the further work thats needed with each procedure to discover whether a particular embryo is viable. These were the most delicate moral questions, and what Mary is rightly celebrated for is that she took them so seriously, listened well that was her great gift, I think and conducted a very long, slow and effective process which ended up in the human fertilisation and embryology system that we now have. Its been amended a couple of times, but its a piece of legislation that has stood the test of time and is widely envied.

I next met her in the House of Lords where she was a fellow crossbencher and we would always have a good chat. She was a late joiner, like most crossbenchers, and neither of us was enormously vocal. We listened hard and did what we could. After she retired from the Lords, she would come in from time to time and wed always have a quick chat in the corridor. Her hearing like my own was not so good, but she was always very alert and energetic.

She once claimed that she was never a real blood and bones philosopher, or much good at the subject, but I do not believe that. She emerged from a very distinctive philosophical culture, as one of a formidable group of women in philosophy posts in Oxford who probably would not have got their jobs, or would have had a harder time getting them, had it not been for the war and large numbers of male philosophers off serving in the forces. While a lot of Oxford philosophy in that generation was extremely influenced by AJ Ayer and logical positivism, Mary Warnock, like Iris Murdoch, wrote on existentialism. They were interested in the virtues, in the imagination, in what we now call action theory, and were very removed from the positivistic culture that dominated in Oxford at the time.

What Mary will be most remembered for, though, is her contribution to public life. Most public reports have limited effect, but her report on fertilisation and embryology has had a profound influence. There are many people who would not be alive today, but for the approach it took to IVF. It is fascinating to think that one person, by being reasonable and a good listener, can have such an impact.

More:
Mary Warnock remembered by Onora O'Neill | Books - The Guardian