Sometime in the future, we might have the technology to extend lifespans indefinitely and make people effectively immortal. When and how this might happen is a complicated question that I will not go into. Instead, I will take heed of Ian Malcolm in Jurassic Park, who complains that "your scientists were so preoccupied with whether or not they could that they didn't stop to think if they should".

This is (in my opinion rather surprisingly) a controversial question.

The core of it is this: should people die?

Often the best way to approach a general question is to start by thinking about specific cases. Imagine a healthy ten-year old child; should they die? The answer is clearly no. What about yourself, or your friends, or the last person you saw on the street? Wishing for death for yourself or others is almost universally a sign of a serious mental problem; acting on that desire even more so.

There are some exceptions. Death might be the best option for a sick and pained 90-year-old with no hope of future healthy days. It may well be (as I've seen credibly claimed in several places) that the focus on prolonging lifespan even in pained terminally ill people is excessive. "Prolong life, whatever the cost" is a silly point of view; maximising heartbeats isn't what we really care about.

However, now imagine a pained, dying, sick person who has a hope of surviving to live many healthy happy days – say a 40-year-old suffering from cancer. Should they die? No. You would hope that they get treatment, even if it's nauseating fatiguing painful chemotherapy for months on end. If there is no cure, you'd hope that scientists somewhere invent it. Even if it does not happen in time for that particular person, at least it will save others in the future, and eliminate one more horror of the world. It would be a great and celebrated human achievement.

What's the difference between the terminally ill 90-year-old and the 40-year-old with a curable cancer? The difference is technology. We have the technology to cure some cancers, but we don't have the technology to cure the many ageing-related diseases. If we did, then even if the treatment is expensive or difficult, we would hope – and consider it a moral necessity – for both of them to get it, and hope that they both go on living for many more years.

No one dies of time. You are a complex process running on the physical hardware of your brain, which is kept running by the machine that is the rest of your body. You die when that machine breaks. There is no poetic right time when you close your eyes and get claimed by time, there is only falling to one mechanical fault or another.

People (or conscious beings in general) matter, and their preferences should be taken seriously – this is the core of human morality. What is wrong in the world can be fixed – this is the guiding principle of civilisation since the Enlightenment.

So, should people die? Not if they don't want to, which (I assume) for most people means not if they have a remaining hope of happy, productive days.

Counterarguments

The idea that death is something to be defeated, like cancer, poverty, or smallpox, is not a common one. Perhaps there's some piece of the puzzle that is missing from the almost stupidly simple argument above?

One of the most common counterarguments is overpopulation (perhaps surprisingly; environmentalist concerns have clearly penetrated very deep into culture despite not being much of a thing before the 1970s). The argument goes like this: if we solve death, but people keep being born, there will be too many people on Earth, leading to environmental problems, and eventually low quality of life for everyone.

The object-level point (I will return to what I consider more important meta-level points later) is that demographic predictions have a tendency to be wrong, especially about the future (as the Danish (?) saying goes). Malthus figured out pre-industrial demographics just as they came to an end with the industrial revolution. In the 1960s, there were warnings of a population explosion, which fizzled out when it turned out that the demographic transition (falling birth rates as countries develop) is a thing. Right now the world population is expected to stabilise at less than 1.5x the current size, and many developed countries are dealing with problems caused by shrinking populations (which they strangely refuse to fix through immigration).

Another concern are the effects of having a lot of old people around. What about social progress – how would the development of women's rights have been realised if you had a bunch of 19th century misogynists walking around in their top hats? What sort of power imbalances and Gini coefficients would we reach if Franklin Delano Roosevelt could continue cycling through high-power government roles indefinitely, or Elon Musk had time to profit from the colonisation of Mars? What happens to science when it can no longer advance (as Max Planck said) one funeral at at time?

(There is even an argument that life extension technology is problematic because the rich will get it first. This is an entirely general and therefore entirely worthless argument, since it applies to all human progress: the rich got iPhones first – clearly smartphones are a problematic technology, etc., etc. If you're worried about only the rich having access to it for too long, the proper response is to subsidise its development so that the period when not everyone has access to it is as short as possible.)

These are valid concerns that will definitely test the abilities of legislators and voters in the post-death era. However, they can probably be overcome. I think people can be brought around surprisingly far on social and moral attitudes without killing anyone. Consider how pre-2000 almost anyone's opinions would have made them a near-pariah today; many of those people still exist and it would hard to write them off as a total loss. Maybe some minority of immortal old people couldn't cope with all the Pride Parades – or whatever the future equivalent is – marching past their windows and they go off to start some place of their own with sufficient top hat density; then again, most countries have their own conservative backwater region already. If they start going for nukes, that's more of an issue, but not more so than Iran.

As for imbalances of power and wealth, it might require a few more taxes and other policies (the expansion of term limits to more jobs?), but given the strides that equalising policy-making has made it seems hard to argue there is a fundamental impossibility.

And what about all the advantages? A society of the undying might well be far more long-term oriented, mitigating one of the greatest human failures. After all, how often do people bemoan that 70-year-old oil executives just don't care because they won't be around to see the effects of climate change?

What about all the collective knowledge that is lost? Imagine if people in 2050 could hear World War II veterans reminding them of what war really is. Imagine if John von Neumann could have continued casually inventing fields of maths at a rate of about two per week instead of dying at age 53 (while absolutely terrified of his approaching death). Imagine if we could be sure to see George R. R. Martin finish A Song of Ice and Fire.

Also, concerns like overpopulation and Elon Musk's tax plan just seem small in comparison to the literal eradication of death.

Imagine proposing a miracle peace plan to the cabinets of the Allied countries in the midst of World War II. The plan would end the war, install liberal governments in the Axis powers, and no one even has to nuke a Japanese city. (If John von Neumann starts complaining about not getting to test his implosion bomb design, give him a list of unsolved maths problems to shut him up.) Now imagine that the reaction is somewhere between hesitance and resistance, together with comments like "where are we going to put all the soldiers we've trained?", "what about the effects on the public psyche of a random abrupt end without warning?", and "how will we make sure that the rich industrialists don't profit too much from all the suddenly unnecessary loans that they've been given?" At this point you might be justified in shouting: "this war is killing fifteen million people per year, we need to end it now".

The situation with death is similar, except it's over fifty million per year rather than fifteen. (See this chart for breakdown by cause – you'll see that while currently-preventable causes like infectious diseases kill millions, ageing-related ones like heart disease, cancer, and dementia are already the majority.)

Thought experiments

To make the question more concrete, we can try thought experiments. Imagine a world in which people don't die. Imagine visitors from that world coming to us. Would they go "ah yes, inevitable oblivion in less than a century, this is exactly the social policy we need, thanks – let us go run back home and implement it"? Or would they think of our world like we do of a disease-stricken third-world country, in dire need of humanitarian assistance and modern technology?

It's hard to get into the frame of mind of people who live in a society that doesn't hand out automatic death sentences to everyone at birth. Instead, to evaluate whether raising life expectancies to 200 makes sense even given the environmental impacts, we can ask whether a policy of killing people at age 50 to reduce population pressures would be even better than the current status quo – if both an increase and decrease in life expectancies is bad, this is suspicious because it implies we're at the optimum by chance. Or, since the abstract question (death in general) is always harder than more concrete ones, imagine withholding a drug that manages heart problems in the elderly on overpopulation grounds.

You might argue that current life expectancies are optimal. This is a hard position to defend. It seems like a coincidence that the lifespan achievable with modern technology is exactly the "right" one. Also, neither you nor society should not make that choice for other people. Perhaps some people get bored of life and readily step into coffins at age 80; many others want nothing more than to keep living. People should get what they want. Forcing everyone to conform to a certain lifespan is a specific case of forcing everyone to conform to a certain lifestyle; much moral progress in the past century has consisted of realising that this is bad.

I think it's also worth emphasising one common thread in the arguments against solving death: they are all arguments about societal effects. It is absolutely critical to make sure that your actions don't cause massive negative externalities, and that they also don't amount to defecting in prisoner's dilemma or the tragedy of the commons. However, it is also absolutely critical that people are happy and aren't forced to die, because people and their preferences/wellbeing are what matters. Society exists to serve the people who make it up, not the other way around. Some of the worst moral mistakes in history come from emphasising the collective, and identifying good and harm in terms of effects on an abstract collective (e.g. a nation or religion), rather than in terms of effects on the individuals that make it up. Saying that everyone has to die for some vague pro-social reason is the ultimate form of such cart-before-the-horse reasoning.

Why care about the death question?

There are several features that make the case against death, and people's reactions to it, particularly interesting.

Failure of generalisation

First: generalisation. I started this post using specific examples before trying to answer the more general question. I think the popularity of death is a good example of how bad humans are at generalising.

When someone you know dies, it is very clearly and obviously a horrible tragedy. The scariest thing that could happen to you is probably either your own death, the death of people you care about, or something that your brain associates with death (the common fears: heights, snakes, ... clowns?).

And yet, make the question more abstract – think not about a specific case (which you feel in your bones is a horrible tragedy that would never happen in a just world), but about the general question of whether people should die, and it's like a switch flips: a person who would do almost anything to save themselves or those they care about, who cares deeply about suffering and injustice in the world, is suddenly willing to consign five times the death toll of World War I to permanent oblivion every single year.

Stalin reportedly said that a single death is a tragedy, but a million is only a statistic. Stalin is wrong. A single death is a tragedy, and a million deaths is a million tragedies. Tragedies should be stopped.

People These Days

Second: today, we're pretty good at ignoring and hiding death. This wasn't always the case. If you're a medieval peasant, death is never too far away, whether in the form of famine or plague or Genghis Khan. Death was like an obnoxious dinner guest: not fun, but also just kind of present in some form or another whether you invited them or not, so out of necessity involved in life and culture.

Today, unexpected death is much rarer. Child mortality globally has declined from over 40% (i.e. almost every family had lost a child) in 1800 to 4.5% in 2015, and below 0.5% in developed countries. Famines have gone from something everyone lives through to something that the developed world is free from. War and conflict have gone from common to uncommon. Much greater diseases and accidents can be successfully treated. As a result of all these positive trends, death is less present in people's minds.

As I don't have my culture critic license yet, I won't try to make some fancy overarching points about how People These Days Just Don't Understand and how our Materialistic Culture fails to prepare people to deal with the Deep Questions and Confront Their Own Mortality. I will simply note that (a) death is bad, (b) we don't like thinking about bad things, and (c) sometimes not wanting to think about important things causes perverse situations.

Confronting problems

Why do people not want to think that death is bad? I think one central reason is that death seems inevitable. It's tough to accept bad things you can't influence, and much easier to try to ignore them. If at some point you have to confront it anyways, one of the most reassuring stories you can tell is that it has a point. Imagine if over two hundred thousand years, generation after generation of humans, totalling some one hundred billion lives, was born, grew up, developed a rich inner world, and then had that world destroyed forever by random failures, evolution's lack of care for what happens after you reproduce, and the occasional rampaging mammoth. Surely there must be some purpose for it, some reason why all that death is not just a tragedy? Perhaps we aren't "meant" to live long, whatever that means, or perhaps it's all for the common good, or that "death gives meaning to life". Far more comforting to think that then to acknowledge that a hundred billion human lives and counting really are gone forever because they were unlucky enough to be born before we eradicated smallpox, or invented vaccines, or discovered antibiotics, or figured out how to reverse ageing.

Assume death is inevitable. Should you still recognise the wrongness of it?

I think yes, at least if you care about big questions and doing good. I think it's important to be able to look at the world, spot what's wrong about it, and acknowledge that there are huge things that should be done but are very difficult to achieve.

In particular, it's important to avoid the narrative fallacy (Nassim Taleb's term for the human tendency to want to fit the world to a story). In a story, there's a start and an end and a lesson, and the dangers are typically just small enough to be defeated. Our universe has no writer, only physics, and physics doesn't care about hitting you with an unsolvable problem that will kill everyone you love. If you want to increase the justness of the world, recognising this fact is an important starting point.

Taxes

Is death inevitable? In considering this question, it's important once again to remember that death is not a singular magical thing. Your death happens when something breaks badly enough that your consciousness goes permanently offline.

Things, especially complex biological machines produced by evolution, can break in very tricky ways. But what can break can be fixed, and people who declare technological feats impossible have a bad track record. The problem might be very hard: maybe we have to wait until we have precision nano-bots that can individually repair the telomeres on each cell, or maybe there is no effective general solution to ageing and we face an endless grind of solving problem after problem to extend life/health expectancies from 120 to 130 to 140 and so forth. Then again, maybe someone leaves out a petri dish by accident in a lab and comes back the next day to the fountain of youth, or maybe by the end of the century no one is worrying about something as old-fashioned as biology.

There's also the possibility of stopgap solutions, like cryonics (preserving people close to death by vitrifying them and hoping that future technology can revive them). Cryonics is currently in a very primitive state – no large animals successfully having been put through it – but there's a research pathway of testing on increasingly complex organs and then increasingly large animals that might eventually lead to success if someone bothered to pour resources into it.

There is no guarantee when this is happening. If civilisation is destroyed by an engineered pandemic or nuclear war before then, it will never happen.

Of course, in the very long run we face more fundamental problems, like the heat death of the universe. Literally infinite life is probably physically impossible; maybe this is reassuring.

Predictions and poems

I will make three predictions about the eventual abolition of death.

First, many people will resist it. They might see it as conflicting with their religious views or as exacerbating inequality, or just as something too new and weird or unnatural.

Second, when the possibility of extending their lifespan stops being an abstract topic and becomes a concrete option, most people will seize it for themselves and their families.

This is a common path for technologies. Lightning rods and vaccines were first seen by some as affronts to God's will, but eventually it turns out people like not burning to death and not dying of horrible diseases more than they like fancy theological arguments. Most likely future generations will discover that they like not ageing more than they like appreciating the meaning of life by definitely not having one past age 120.

Finally, future people (if they exist) will probably look back with horror on the time when everyone died against their will within about a century.

Edgar Allen Poe wrote a poem called "The Conqueror Worm", about angels crying as they watch a tragic play called "Man", whose (anti-)hero is a monstrous worm that symbolises death. If we completely ignore what Poe intended with this, we can misinterpret one line to come to a nice interpretation of our own. The poem declares that the angels are watching this play in the "lonesome latter years". Clearly this refers to a future post-scarcity, post-death utopia, and the angels are our wise immortal descendants reflecting on the bad old days, when people were "mere puppets [...] who come and go / at the bidding of vast formless things" like famine and war and plague and death. The "circle [of life] ever returneth in / To the self same spot [= the grave]", and so the "Phantom [of wisdom and fulfilled lives] [is] chased for evermore / By a crowd that seize it not".

Death is a very poetic topic, and other poems need less (mis)interpretation. Edna St. Vincent Millay's "Dirge Without Music" is particularly nice, while Dylan Thomas gives away the game in the title: "Do not go gentle into that good night".