During the nine long, hard years Philip Whitaker spent qualifying as a GP he dreamt of becoming a writer - and the dream won. Now his first novel has been nominated for a Whitbread prize.

"At school, I had always been best at sciences and very swotty - as a teenager I would read the New Scientist for pleasure. I was fascinated by the logical nature of sciences and how they are mainly concerned with explaining things that are unexplainable. I was due to study Biochemistry at University but the summer after leaving school I had my doubts; I didn't want to end up in a laboratory looking down microscopes all my life. Instead, I decided to become a doctor.

As part of my training at Nottingham I made a home follow-up to an elderly man who had advanced cancer of the prostate. In hospital it was all very medical and professional but the impact of meeting him again with his wife was quite profound. The visit was intended for students to discover how disease affects patients' lives, but I had an enormous number of feelings going round in my brain - especially watching the pair of them together trying to cope with the idea that he might be dying. They lived quite a way outside Nottingham and I remember travelling back to the city, wrestling with the dilemma of being a vulture by learning from others' misfortune. There was no formed decision but I came home and just switched on my computer and started writing a story. I don't know why, because I'd never done it before, it just felt like the thing to do. I didn't think that writing would help, I just had to express myself, but afterwards it did feel cathartic. For the first time ever, I could not understand by using my rational scientist's mind.

The training was interesting but also very demoralising. I greatly enjoyed my first three years of studying the science and all the student societies but the workload for doctors, and the effect on their lives, is terrible. After graduating, you have to do a minimum of three years in hospital. As a House Officer I became chronically tired, lost weight and was very ill. I had no social life and didn't see friends from one end of the year to the next. I would work 72 hours on the trot, sometimes with only two or three hours sleep over a whole weekend. I remember a patient of mine laughing - I had sat down at my desk to chase test results but kept falling asleep on the phone. It was pretty grim and I began to think, "I don't want to do this anymore." I felt completely brain dead. It knocks any sense of being a human being out of you.

I seriously contemplated what else I could do - which was disconcerting and even a little frightening. Studying to become a doctor took five years and further training is another four. I was investing nine years of my life. It was a bit late to think you've had a bum deal! There was a great tension - the work is satisfying but the way it is structured puts an intolerable pressure on you. As a trainee I didn't have the medical knowledge to discuss with patients what was going to happen with their disease, instead I would talk at the more human level about whether they were frightened and how everything was affecting them. Later, there was so much pressure that this style was difficult to maintain. I'd become much more interested in people than in illness.

I eventually qulified as a GP, but I had a horrible vision of myself sat in a surgery in my late forties having never tried a career in writing and being deeply regretful. Although you have to think about income and security, they shouldn't overwhelm the equation and stop you doing something important. Writing is my passion and we only have one chance - life is not a rehearsal. So I decided to stop working full time. Two words re- occur every time anybody describes my decision to stop to follow my dream of writing fiction: brave or courageous. In Yes, Minister-speak that means they think it is a completely stupid thing to do and that I'm nuts, but it felt like I had no choice.

Fortunately, Lynn (the woman I was cohabiting with and later married) was very supportive because to start off with I didn't make a penny and spent our savings. I decided to study creative writing at the University of East Anglia and was casting around for something to write a novel about when there was a solar eclipse in India. I was fascinated by the debate of science versus myth and how Indian rationalists were trying to counter their society's superstitions about how eclipses bring disastrous events. It struck a deep chord with my conflict between the science in medicine and the humanity of people. Although Eclipse of the Sun has nothing from my life in it, the book is deeply autobiographical! It has the two sides of my personality embodied in it, the husband is a scientist and the wife is spiritual. I set them against each other and allow them to tussle it out on the page. Neither side wins - although the science and rational side comes off slightly worse. A bit like my personality, neither part is likely to be ascendant over the other but exist in a relatively uneasy harmony. Science is a tremendously important part of human knowledge but it is not so important that it should override the spiritual aspects.

If I'd followed my original career as a laboratory scientist I would have gone potty. In general practice there's much more human interaction alongside the science and that's probably why I went into that aspect of medicine. I'm not earning enough money to support myself by writing, so I work on a locum basis. Although I feel I can do some good as a doctor and make some difference to my patients' lives, if that was all I did I wouldn't feel completely satisfied. Now I'm definitely more of an artist than a scientist, I believe that writing and the arts are tremendously important to feed the human spirit while medicine is just concerned for the body. If I were to read again that first short story I wrote after visiting the cancer patient, I would probably think it naive yet it spoke powerfully about what I was feeling and brought the humanity of that man's experience to the forefront - that's why it was such a transforming moment. These days I'm getting less in touch with rationality, which sounds like I'm going mad. But my education at school and university was all science whereas now I see that as a small corner of human activity, relationships and culture are equally if not more important to people's lives. I'm certainly a lot happier not spending all my life in the scientific world, I'm more in touch with my own humanity which years of hospital doctoring had squashed flat."

Philip Whitaker's `Eclipse of the Sun' is published by Phoenix House at pounds 16.99.