I am holding my granddaughter, not yet half a day old. Is it this stage of my life already? I'm scarcely middle-aged, surely. I'll have to do something reckless to reaffirm my youth. But I catch a glimpse of myself in the window against the darkening day, babe in arms. Don't kid yourself, granddad.

We are all getting older, all heading for the same conclusion. Is there no way out? The other day I received an invitation to contribute to a “Colloquium on the Law of Futuristic Persons”. A futuristic person, apparently, is “a being who claims to have the rights and obligations of a human but who may be beyond accepted notions of legal personhood”. You are a futuristic person if, for example, your mind runs on a computer rather than a brain, or if you have been brought back to life after a period of legal death spent, say, in the deep chill of a cryonic vault.

The (at present very remote) prospect of having your conscious mind uploaded on to a computer may not be so enticing, but who wouldn't choose to extend flesh and blood life by the fruits of biomedical science? We do so already, of course, taking the life-sustaining gifts of modern medicine for granted.

Given the chance of a little more life, and yet a little more, most of us would take it, eking out our lives indefinitely. We'd keep on keeping on. And radically increased longevity is no longer a fantasy. Quite likely, as the present century unfolds, advances in genetic engineering, nanotechnology and regenerative medicine will deliver on their life-extending promise, at least for a rich and privileged few. According to the Cambridge gerontologist Aubrey de Grey, a “cure” for human ageing is just around the corner.

Periodic repairs to the bodily machinery using methods already within the scope of science - stem-cell treatments, gene therapies and the like - have the potential to halt the ageing process, in effect to reverse it. De Grey believes that the first person to reach 1,000 years of age has probably already been born. Onwards to immortality. But would I really want to live forever, even for 1,000 years? Oh, I think I'd give it a go.

One argument against is that a life stretching interminably into the future would become terminally boring. There are only so many places to visit, so many symphonies to hear, so many lovers to embrace. Yes, so many! Life is infinitely rich. The possibilities for new knowledge and experience are endless. So I don't buy the boredom argument. As the philosopher John Harris put it, only the terminally boring are in danger of becoming terminally bored.

Another argument doubts the durability of human identity. It goes like this. I may opt for immortality but as the millennia roll out I would become vastly altered, physically and mentally. Constantly re-engineered, my body would change shape, colour and proportion according to fashion, and my brain capacity would be boosted a thousand-fold by neural implants. I would no longer be “me”.

The quest for immortality is thus literally self-defeating. But is this so different to the changes we undergo in the course of an ordinary lifetime? Our bodily tissues are continually renewed with cells dying and being replaced. The average age of the cells that make up an adult human body (that is, your “true” physical age) is around 7-10 years. Our physical and mental structures are in constant flux. Only patterns survive. Life extension would just mean more of the same.

Death is a damn nuisance. There'll be no solution in my lifetime. Nor yours, I fear. Or, let's face it, probably ever. But, do you know what, with a newborn baby in my arms I really couldn't care less. As John Updike says: “We are immortal for as long as we live.”

Paul Broks is Senior Clinical Lecturer in Psychology at the University of Plymouth

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