These thinkers believe genetic engineering, or the discovery of anti-ageing drugs, could extend human life far beyond its natural course.
Indeed, Australian geneticist David Sinclair believes such a pill could be as close as ten years away. Cambridge researcher Aubrey de Grey thinks there is no reason humans cannot live for at least 1,000 years.
It's certainly an enticing prospect, which has investors jumping on board. In 2013, Google started Calico, short for the California Life Company. Employing scientists from the fields of medicine, genetics, drug development and molecular biology, Calico's aim is to "devise interventions that slow ageing and counteract age-related diseases".
Those who fear death and want to live as long as possible would welcome this kind of research. But many philosophers and ethicists are sceptical about the implications of longer lifespans, both for the individual and society. Their doubts recall the old saying: be careful what you wish for.
For some, the idea of living longer is a no-brainer. According to bioethicist John Harris, the commitment to extending life indefinitely is justified by the same reasoning that commits us to saving lives. He believes scientists have a moral obligation to do so.
But Leon Kass, a former US presidential advisor on bioethics, takes the concept of eternal life deeper than simply "life is good and death is bad". He asks whether, if the human lifespan were increased, its pleasures would also increase proportionally.
Would professional tennis players really enjoy playing 25% more games of tennis? Would the Don Juans of our world feel better for having seduced 1,250 women rather than 1,000?
He wonders if life would be as serious or meaningful without mortality's limit. Kass believes an end point encourages us to make the most of our time, to live it passionately and struggle to achieve our goals in the short time that we have. In other words, "mortality makes life matter".
Philosopher Larry Temkin is similarly concerned about whether anything would strike him as new, exciting or bewitching if he lived forever. He echoes a worry many philosophers have about the prospect of immortality: all activities and experiences that make our lives interesting would become boring and meaningless after thousands of repetitions.
Loss of self
Temkin expresses another philosophical worry about a vastly extended human life. Our ability to remember is probably limited. As we age we tend to forget many things that happened earlier in our lives. Perhaps people who live for 1,000 years or more will forget altogether what happened in the earlier parts of their existenc
Even if their early lives were on record, they might have a hard time recognising these recorded experiences as belonging to them. Temkin says were he to live long enough, he might become so distanced from his first set of children that he would no longer care for, or even remember, them.
Echoing this, philosopher Bernard Williams thinks an extended life would be destructive of identity. As memories are lost and people change their characters and interests during the course of a very long life, they would lose contact with the person they used to be.
Williams thinks attempting to prolong our existence is self-defeating. The self that we want to preserve would, after a time, no longer exist.
But defenders of anti-ageing research, such as Harris, think long-living people would adjust to their new condition and find new ways of valuing and enjoying life.
Even so, social and ethical concerns raised by critics of longevity are not so easy to set aside.
Many critics fear life-prolonging treatments aren't likely to be available to everyone. Wealthy people, including powerful autocrats in poor countries, will be able to afford them. The poor will not.
The prospect of a 1,000-year-reign for the likes of Kim Jong Un, North Korea's leader, is not appealing.
But let's say most people would be able to extend their lives. If they continued to have children, then the world would be even more overpopulated than today. And the prospects for younger people won't be bright if older people, with their wealth of experience, continue to fill available jobs and retain their hold on power.
If children are to flower, says Kass, then we must go to seed. The flourishing of the young is important not only for their own sake. Young people are often the source of innovation and social progress.
Harris thinks if we were to overpopulate like this, some form of "generational cleansing" might be necessary. This would mean authorities deciding the length reasonable for a generation to live and ensuring individuals died once they reached the end of their term. Once they have had a "fair go", the old should be prepared to leave the world to the young.
It would be ironic, however, if a cure for death meant that people had to be forced to die.
But the issues described above are unlikely to be a deterrent. If we truly get a chance to sip from the Fountain of Youth, many are likely to take it.
Just in case the possibility comes about, Temkin thinks now is a good time to reflect on why life is valuable. "If your life isn't meaningful at 70 years, it's not going to be meaningful just because it's a lot longer," he says.
Image: Pranjal Mhana