Maurice Pappworth, the great if controversial doctor, was the most awe-inspiring person I’ve ever known. From the moment you edged into his presence, you felt that you were being scrutinised and judged, not always benignly. I met his eldest daughter, Joanna, while directing plays at Oxford in our first summer in 1974. Not until the summer of 1978 did we become an item, which meant that my first encounter with the feared Dr Pappworth could not be delayed much longer.

I met him first in the summer of 1979 if I remember correctly, at his home on Hampstead Heath. He made it very clear that he did not approve of his daughter’s new partner. It was a small consolation to learn that he was even more dismissive of my predecessor for Joanna’s affection, the film director Alex Cox. The inescapable fact was that, while my father was Jewish, my mother was not. For the next two years I saw nothing of him until we decided to become engaged. I wrote him a long letter asking for his daughter’s hand, saying that I had decided to convert to Judaism. Even this was not good enough because I could only convert into the Reform, not his own Orthodox branch. He had pronounced views on the Reform movement, as he did on most things in life, and they were not markedly positive. No matter that the man overseeing my spiritual conversion, and the person who would marry us, was none other than Rabbi Hugo Gryn, distinguished academic and broadcaster, and survivor of Auschwitz.

My parents could not understand how anyone could fail to be won over by their youngest son. They hatched a plot. When Joanna and I returned from a journey to Israel from the marriage of Joanna’s middle sister, they turned up to meet us at Heathrow, and bundled him into the back seat of their conveniently parked blue Jaguar. They gambled that the temptation of a lift to his home in Hampstead would prove too much for him to resist. They were right, but he let his disapproval of them be known by remaining silent in the back seat all journey.

After much persuasion, he agreed to come to our wedding at the West London Synagogue. But on the firm instructions of Joanna’s grandmother, he was forbidden to speak. What an odd family I remember thinking to myself but I loved Joanna, and Joanna loved her father. He gave me the distinct feeling that she was his favourite daughter of the three sisters. He photographed her endlessly as a child and spoke to her more often than perhaps he should on a whole range of issues including his deteriorating relationship with his wife. When he died in 1994, I broke the news to Joanna in the children’s playroom in our home in Bromley. I will never forget the yell of anguish that emanated from deep inside her. Joanna was always extraordinarily vulnerable and sensitive: it was as if she lacked a skin of self-preservation, and I loved her all the more for it.

Her father fell out with the medical profession throughout his life. She lived for another 22 years: somewhere in that time she decided that she would write a book about him. She continued to miss him and continued to see him as a key reference point in his life. For all his abrasiveness she always saw him as gentle, wise and kind. She felt his pain too, notably the lack of recognition from his medical establishment. He blamed the antipathy on his Jewishness, famously being told before the Second World War that he could never become a consultant because “no Jew could ever be a gentleman.” So he fought his way up the greasy pole as an outsider, gaining a status from his admirers as the best medical teacher in the UK. I admired him greatly as a courageous and principled man.

His most important single contribution was the publication in 1967 of his book The Human Guinea Pigs: Experimentation on Man. During the preceding 15 years, he had become increasingly concerned by unethical experiments on human beings, often without the full knowledge of the patient. The book caused a sensation when it was published. It detailed experiments on children and inmates of mental and penal institutions, whose lives were often damaged for what he believed were the career enhancements of the medics involved. The end, he said, did not justify the means. The book was widely reviewed. Arthur Koestler, author of Darkness at Noon reviewed it famously in the New Statesman. He was scathing about the experiments described in the book as “carried out on children, on pregnant women, mental defectives, on patients before and after an operation” and those with incurable diseases.

When Joanna became ill in 2011 with a comparatively rare and incurable cancer her thoughts turned increasingly to her father and to writing his book. On the night of 20th February 2012, she lay in bed in the Royal Marsden Hospital in Chelsea awaiting an operation the next morning to arrest the spread of cancer in her liver. She later described how she had a visitation from her father: “there can be absolutely no doubt that at that moment I felt the presence of my father more strongly than I ever had since his death nearly 18 years earlier. Maurice Pappworth the physician-friend was watching over me.” That was when I think she definitely decided to write the biography herself to which she dedicated much of the final year of her life. She displayed extraordinary courage and determination to complete the project, which included travelling to Poland, from where the family of her beloved father came. We stayed in Warsaw and visited the town where he lived Lomza, and travelled to Treblinka where some of her family perished at the hand of the Nazis. She completed the book just 10 days before her death in December 2016. On her final visit to her beloved France over half term last autumn, she received the news that both her poetry and the book on her father were to be published the following year. One of her poems, Prayer, unites both projects, and was one of the last she wrote.

My father/Who healed the sick/Now too far away/To heal me,/Stir your spirit/To remind me/What it is to live/The best that can be/Lived/So long as I am/Here.

Sir Anthony Seldon is a political historian and commentator on British political leadership as well as on education and contemporary Britain

The Whistle-Blower by Joanna Seldon is published by the University of Buckingham Press