Let us consider me as a test case. As I have said, I would like to die peacefully with Thomas Tallis on my iPod before the disease takes me over and I hope that will not be for quite some time to come, because if I knew that I could die at any time I wanted, then suddenly every day would be as precious as a million pounds. If I knew that I could die, I would live. My life, my death, my choice.

Every 90 days I lie in a whirling CT machine, dye coursing through my veins, and the doctors look to see whether the tumors in my liver are growing. If they are not, the doctors smile and schedule another scan. The rhythm has been the same since my doctors told me I had stage IV colon cancer two and a half years ago. I live for three months, take a deep breath and hope to start over again. I will probably do this for the rest of my life. Whatever that means.

what’s the difference? If I die in two years’ time, what will I do between now and then which I don’t want to do now? The main reason for living longer now is for the sake of my family and my wife. And this is not rationalist bravado entirely. I’ve had a wonderful life. Yes, I’ve done a lot of things I shouldn’t have done. But you know, I’ve had a full, complete life, and there’s nothing more I can do to complete it. Dying when you’re younger is obviously a totally different situation. Or losing a child. I mean, that’s beyond words.

I live by the day. Just sitting in the park, looking at the flowers thinking how beautiful they are. It's almost … not hallucinogenic but it's a much stronger feeling than previously. For me, at the moment, going for a walk in the park with Gail is heaven.

The first biography I read — I think the first scientific biography — was Madame Curie . And my mother, who was a surgeon, worked at the Marie Curie Hospital. She’d met Marie Curie, who was one of her great heroines. And reading the book, I think, was the first portrait of a scientist and the romance of a scientific life.

My generation is on the way out, and each death I have felt as an abruption, a tearing away of part of myself. There will be no one like us when we are gone, but then there is no one like anyone else, ever. When people die, they cannot be replaced. They leave holes that cannot be filled, for it is the fate — the genetic and neural fate — of every human being to be a unique individual, to find his own path, to live his own life, to die his own death.

And now, weak, short of breath, my once-firm muscles melted away by cancer, I find my thoughts, increasingly, not on the supernatural or spiritual, but on what is meant by living a good and worthwhile life — achieving a sense of peace within oneself. I find my thoughts drifting to the Sabbath, the day of rest, the seventh day of the week, and perhaps the seventh day of one’s life as well, when one can feel that one’s work is done, and one may, in good conscience, rest.

And I spent four years at a boarding school in the country, probably a rather abusive boarding school, and seeing very little of my parents, and that was a very bad time for me. A bad and almost a mad time. ... I think that some sort of trust, and ability for closeness, may have been compromised. And I think I’ve perhaps, to some extent, sort of kept a distance since that time, although this is not a distance I feel with my patients or my students.

It was this celestial splendor that suddenly made me realize how little time, how little life, I had left. My sense of the heavens’ beauty, of eternity, was inseparably mixed for me with a sense of transience — and death. ... I told my friends Kate and Allen, “I would like to see such a sky again when I am dying.” “We’ll wheel you outside,” they said.

I’ve had this concern all the time, but I can only hope that if one writes with appreciation and delicacy and respect, then it’s okay. I have to say that I’ve written a hundred times as much as I’ve published, because if there’s any thought of offense or embarrassment, then I will put the thing quietly away.