Stephen Cave

The ancient quest for human immortality has collided with ultra-modern developments in biology and AI. Billion-dollar start-ups, funded by tech moguls, seek to add decades to human life.  

But philosopher and writer Stephen Cave, a researcher at Cambridge University in Britain, says life extension technology is fraught with ethical problems.  

Guyon Espiner talked to Stephen about why we need to start taking the promise of extending our lifespans seriously. 

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"The claim that we're on the verge of defeating ageing or disease is an ancient one, as old as human history. Ancient Egyptian papyri were talking about the elixir of life. Mummification was just a backup plan for them. Throughout history we see these kinds of claims repeated, over and over again, and the one thing that all these people who claim to have found some kind of rejuvenation elixir have in common, is that they're now all six feet under pushing up daisies."  

"So why should we think this time is different? Well, I think there are a number of reasons. One of them is the reality of scientific and technological breakthroughs. Life expectancy has doubled in the last 150 years from around 40 to around 80 or so in industrialised countries."  

"Now, a lot of that has been from tackling infant mortality. If a lot of people die very young in their first few years, then that pushes down the averages. In industrialised countries, since the 1950s, life expectancy has continued to creep up at about two years per decade. And that's through treatments at the end of life - making cancer diagnoses that would have rapidly been terminal manageable and [identifying] heart disease and so on."  

"Life expectancies are genuinely creeping up to unprecedented levels. And right now, there are vast amounts of money and huge amounts of talent being poured into the anti-ageing research industry."  

The modern quest for the Fountain of Youth is being driven by billionaires with money to spend

"They might make breakthroughs, but whether it's in time for them to achieve what they want, who knows? Because there is a very long history of the super-rich and powerful investing their resources into the pursuit of anti-ageing. It is the one thing that insults their power, the one thing that right now, money can't buy. They're still getting older.  

The first Emperor of China went through all of his country's vast resources, two and a half thousand years ago, into developing an elixir of life. It contained arsenic and killed him at the age of 49. So, will Jeff Bezos do any better?"  

"Well, the reason we have to think that he might, is that there have been genuine breakthroughs in the last few decades in research into ageing. It is now possible in the lab to double the lifespan of some organisms. So, we know it's possible to tweak the mechanisms of ageing. The question is, how can we do that? Not just in nematodes and other tiny organisms like fruit flies, but how can we do it in vastly more complex organisms, like humans." 

The belief in an eternal soul  

"If we're asking, what would it be like to live forever? That might seem like an impractical question...the vast majority of people do believe that they're going to live forever, in some form or another. It really is a staple of the great world religions; they're promising, in some way, that we can defeat death.  

Now increasingly, large numbers of people don't believe in the world religions. So, what do they turn to, to reassure them that death is death is not inevitable? Well, they turn to science and technology." 

What makes us human?  

"What makes us human are these very large brains that allow us to develop a complex sense of self and of other people; to project into the future, to generalise and to plan. And when we look around us...what we see is that all things are mortal, that all people are mortal. And so, we realise that we must die."

"It's possible that some other large-brained creatures like elephants, dolphins and the great apes are aware of this. But the vast majority of species on the planet, most of which are beetles, have no idea that they are, in fact, mortal. They just live in this kind of bliss. Life is just life."  

"We bring death into life. We are, possibly alone of all species, fully aware that all our hopes and dreams and projects...will be thwarted. The worst thing that could possibly happen, inevitably will. And that, of course, is terrifying. And that's why we tell ourselves these stories about how we can defy and deny death." 

Facing our own mortality 

"Many people do have some vague memory of the first time they realised that other people could die. That might be a grandparent, or some other friend or relative. They realise that the world around them is much more fragile than they thought. It tends to come in childhood between the ages of about 5 and 10. Children develop sufficient awareness of self and time and so on, to realise that this might happen to them."  

"And I do remember my own grand grandfather dying, and at first thinking, where has he gone? What does it mean? Has he gone to heaven? Where is that? And of course, I was told Christian stories growing up in Britain in the 70s, and 80s. Then of course, you realise that if he can die, so can my parents.  

Then suddenly you feel very vulnerable, and very fragile. And if they can die, so can I. And that realisation is a hugely pivotal one in growing up, and it leads people to think about their religion and their faith in the stories that they're being told and what it might mean, what heaven might be like, and so on."  

"People move on and get on with their lives, but I somehow never did, and I'm still thinking about it!"

Technology and the quest for longer lives 

"The institution I run in Cambridge is called the Institute for Technology and Humanity, where we think about how technology is transforming the human condition, and how to make that go well."  

"The technological transformations we saw through the Industrial Revolution have led to all the prosperity in the world, fantastic technology that's allowing us to speak from across the world and so on. But it was an extremely bumpy ride. The Industrial Revolution also led to enormous, terrible impacts on established ways of life. People moving from the countries to the cities to work in terrible conditions, the rise of fascism and communism that were instrumental in two world wars, and so on."

"Because these kinds of technologies, whether it's the train, the car, or electricity, have huge impacts on our way of life, in particular if they're general purpose technologies that don't just do one thing, but can have massive impacts on many different kinds of things. And AI is one such technology. People tend to worry about the rise of the robots and so on, but the real issues around AI is what it's going to do to every aspect of technological transformation. It's the kind of ultimate tool that can help us to do anything. The mathematician I.J. Good said about 50 years ago, it's the final invention we ever need make." 

"Because once we've got machines cleverer than we are, we can just leave the process of further invention of even cleverer machines and everything else we want to solve, to the machines. So what that means is all of the processes of scientific and technological discovery, including a remedy for ageing, will now be accelerated by AI."  

Who wants to live forever? 

"If it was really forever, then [my answer] is no, I wouldn't. I think living forever, genuinely, would be a curse. So, the question is, how long would I go? A thousand years? Well, I don't know. Seems a bit risky. 10? Definitely. 100? Maybe."  

"There are ethical challenges, but that doesn't mean they can't be met. I think the kind of challenges that new scientific technological discoveries give rise to need to be balanced with the potential benefits."  

"Of course, if many people would genuinely benefit from longer lives, if they really do have the kind of interests and passions and resources that are needed to make the most of those longer lives, then that will weigh heavily on one side of the scale.  

But there are many ethical considerations that need to be weighed on the other side of the scale, and those are the impact on the structure of our society, economy, social justice, injury, intergenerational justice, but other kinds of justice, too. And of course, the impact on the planet."

The curse of immortality 

"I think it's a terrifying prospect. There are really wonderful explorations of this in literature. The great Argentinian writer George Luis Borges has this wonderful short story, The Immortal, about this Russian Centurion who's looking for this river he’s heard of, that cleanses men of death. And he comes across this absurd city with these scraggly grey creatures in front of it. He calls them troglodytes.  

Then he learns that they are the immortals, and they built this great city. And then enough time passed...and then everything was boring and meaningless to them, and now they just lie in shallow pits, staring at the stars as they pass above. One hadn't moved for so long, a bird had nested on his chest.  

The idea Borges is trying to convey is that given enough time, we'll all do all things. And all of our projects, all of our values will start to break down and become meaningless."  

"But of course, this is hypothetical. And we don't know how long it will take for that to happen."

A goal worth pursuing? 

"It could be, under the right conditions. I think what we mustn't do is blindly stumble into this, because the consequences could genuinely be horrific. The consequences for the planet which could lead to the destruction of ecosystems on which we depend, mass starvation, and so on."  

"But also, the consequences for our society. Again, when thinking about the impact of these transformational technologies, it's not necessarily the most direct impact that we should worry about. It's the broader impact on our economies and societies that lead to massive disruption; civil war, world war, and so on.  

As a rule, it has its root, this kind of disruption, in injustice. So, we must take seriously the possibility of radical life extension seriously exacerbating injustice and think now about how we can set up a society that can accommodate longer lives."

The injustice of a longer life 

"First, it is very likely that any intervention that significantly extends life will be expensive, at least for a significant time. And we would find it very difficult to accept that, I think. Right now, in the UK, the disparities in life expectancy between rich and poor, or different demographics within the country, are about 10 years. Whenever that's reported, it's with a sense of outrage, and rightly so.  

But we're talking about the difference between 70 and 80. And if most people are still dying at 70, or 80, but some can afford to live to 150 or 160 and beyond, we would very likely consider that profoundly unjust."  

"So imagine these very wealthy people who not only have the immense privilege of living longer, but also able to use that to accumulate ever more power and wealth, that's setting us up for conflict.  

We regard it as unjust now, when some people, only through wealth or privilege, can live decades longer than others, but it's still a lot down to luck and genes. People can't reliably buy many years more of life to a very large extent. It's still as true as it was in the Middle Ages.  

If you’ve ever seen these dance macabre scenes, this dance of death where the skeleton is leading the prince and the pauper, the king and the bishop, death is the great equaliser. It's still largely true. But there’s now the possibility that soon it won't be, and I don't think we'll find that acceptable." 

The ecological impact 

"The maths are fairly simple - if people carry on being born, but aren't dying, or dying a lot later, the population will explode. And even if people start to have fewer children, and there is plenty of evidence that as people live longer, they have fewer children, still there will be a population explosion from people living longer, just because of the number of generations who are alive at any one time. So there's a lot of argument about what the carrying capacity of the planet is."

"These arguments are called Malthusian after Thomas Malthus. A couple of hundred years ago, the population was about a billion. It’s now 8 billion. Malthus predicted that the world would soon be unable to support any increase in human population. He was wrong, of course.  

And optimists say, well, therefore all Malthusian arguments are wrong, and it doesn't make any sense to be worried about the carrying capacity of the planet. But that seems to me a bit like someone who turns on the bath and leaves the room, and their spouse says, are you mad? and they go, it’s only half-full, it’s going to be fine. But of course, it isn't going to be fine. There is a limit to the capacity of the bath, in the same way that there's a limit to the carrying capacity of this planet." 

"Now, it's not fixed. It does depend on technology. The amount of people alive today are only supported because of technological breakthroughs, like nitrogen fixation [which increases crop yields]. And there'll be more breakthroughs that do allow more people to live on this planet. But nonetheless, there is a limit to what's possible, at least what's possible while maintaining anything like the kind of biodiversity and rich habitats that I think many people would like to preserve."

Lifespan versus “health span” 

"Lives are getting longer. We've added a lot of extra years to life, but they are not healthy lives. So, the amount of time people spend in some state of debilitation or decrepitude as a percentage of life is staying the same or slightly increasing. Lifespans are increasing, but health spans are not increasing in a way that keeps up with that. So, focusing on keeping people healthier for longer is a really important goal."

"A lot of these extra years are being added by making diseases, that would have killed us quickly, manageable, but also therefore more protracted. It’s not uncommon for people to be living into their 70s, or their 80s, with heart disease, diabetes, multiple forms of cancer. I have relatives in these kinds of conditions. And they have quality of life, but it isn't what it ought to be."  

"But there is a bit of a paradox in aiming for health span, which is that, as a rule, healthy people don't die. So yes, we could aim to increase health span, so people get 80 healthy years. That’s better than 70 healthy years plus 10 years debilitation. But what happens then? We don’t as a rule suddenly drop dead. This is what a lot of people in research in the field would like to happen. I'm not saying they want everyone to drop dead at 80. But what they call the “compression of morbidity,” the period in which people are really suffering from disease, they want to shrink that.  

But it's a very kind of paradoxical thing to aim for. Because as a rule, making diseases manageable, solving the problems of ageing extends life beyond the health span. But it is something that's worth thinking about."

Radical life extension and the structure of society 

"Our lives are based very much on a sense of life stages. Childhood, a period of education and training, a period in which we work, perhaps raise a family, and then of course, retirement. Now, “retirement” is fairly newfangled, about 150 years old. But the idea of life stages is an ancient one. In Hindu culture there is a very clear sense of life stages. It takes people well up into their 80s, even though life expectancy was in their 40s." 

"So we create a structure about how we think about life, how we make our decisions, how much time should we spend as children. What does it mean to put away your childish things, as it says in the Bible, and when should we do that? How much education is enough? When should we start a family? How much savings is enough?  How much retirement can we afford? These are all questions based on a particular conception of how long we will live. And all of that will be blown open, if we double the lifespan." 

"What would marriage look like? What would friendships look like? Would there be no jobs-for-life? What would training look like? In a rapidly moving technological landscape that we live in now, what does it mean to do your education at 20 and still be employable at 65? I think we'll have to take a much less linear approach to life, one that may be where we don't get married at 20, and have a family at 25 and do our job for life until we're 60. We might have 20-year marriages, 20-year careers, and then the whole thing's broken open, and we take a break, and we retrain, and go out dating again. And maybe we end up with the same person and the same job. But maybe not. But we'll have to think of life in radically new ways."

"As more people started living longer, towards the end of the 19th century, early 20th, we invented pensions, we invented retirement, because there were just so many people who otherwise would have been impoverished, living in the poor-houses and so on. But already now, pensions are under strain, because people are living so much longer. So that system is slowly evolving. People might be retiring one or two years later, they might be saving a little bit more. But there's nothing like the radical changes we will need if there are real breakthroughs in anti-ageing technologies."

Life’s too short – or is it? 

"In the lives we lead now, we say, life's too short to watch telly all the time, life’s too short to lie in bed and eat cold pizza, life's too short to play computer games. But of course, if life is indefinitely long, then life isn't too short for any of these things. And so, there's a serious risk of us being stuck in a rut. In a sense, death is a source of all our deadlines, they all cascade from knowing we've only got 70 or 80 years."

"But what's really interesting is that that number of years already seems almost too long to grasp the preciousness of life. People who have a near death experience, or even get a terminal diagnosis, they suddenly relish life much more, because they realise their time is finite. Well, we all should realise our time is finite, because it is. But there's so much of it now, we find it difficult to grasp. So doubling it, I think will only make that more difficult to really grasp."

Preparing for a longer life 

"I recognise I'm coming across as a bit of a curmudgeon about this, and I want to just rebalance that a little bit. Because I think that people who are doing research into how to stop ageing, how to cure diseases of old age and so on, are doing great work. Helping keep humans healthy has been the point of medicine and a huge part of science and technology from the very start, and it is a noble cause."  

"What I'm advocating for is preparedness. We need to take the risks seriously, the personal risks of ennui, meaninglessness and procrastination, the societal risks, and the ecological risks."

Has the first person to live to 150 already been born? 

"That's a good question. If I was a betting man, I’d put 50 pounds on it." 

If living forever is a curse, how long would be a blessing? 

"I'm enjoying my life, I'm happy to say. I'm very lucky. I've got three wonderful daughters, a great job, so I'm not in any hurry to shuffle off my mortal coil. I'd go for 150, right now. We could check in again, then."