It feels odd, possibly even grandiose, to start thinking about the things that could happen in our lifetime that could have an impact — not just over decades, but over centuries, thousands, millions, or even billions of years.
But if we’re taking seriously that future people matter morally, and that it really doesn’t matter when harms or benefits occur, then we really should take seriously this question of whether there could be events that occur in our lifetimes that have not just long-lasting, but indefinitely persistent effects.
- People who exist in the future deserve some degree of moral consideration.
- The future could be very big, very long, and/or very good.
- We can reasonably hope to influence whether people in the future exist, and how good or bad their lives are.
- So trying to make the world better for future generations is a key priority of our time.
This is the simple four-step argument for ‘longtermism’ put forward in What We Owe The Future, the latest book from today’s guest — University of Oxford philosopher and cofounder of the effective altruism community, Will MacAskill.
From one point of view this idea is common sense. We work on breakthroughs to treat cancer or end use of fossil fuels not just for people alive today, but because we hope such scientific advances will help our children, grandchildren, and great-grandchildren as well.
Some who take this longtermist idea seriously work to develop broad-spectrum vaccines they hope will safeguard humanity against the sorts of extremely deadly pandemics that could permanently throw civilisation off track — the sort of project few could argue is not worthwhile.
But Will is upfront that longtermism is also counterintuitive. To start with, he’s willing to contemplate timescales far beyond what’s typically discussed:
If we last as long as a typical mammal species, that’s another 700,000 years. If we last until the Earth is no longer habitable, that’s hundreds of millions of years. If we manage one day to take to the stars and build a civilisation there, we could live for hundreds of trillions of years. […] Future people [could] outnumber us a thousand or a million or a trillion to one.
A natural objection to thinking millions of years ahead is that it’s hard enough to take actions that have positive effects that persist for hundreds of years, let alone “indefinitely.” It doesn’t matter how important something might be if you can’t predictably change it.
This is one reason, among others, that Will was initially sceptical of longtermism and took years to come around. He preferred to focus on ending poverty and preventable diseases in ways he could directly see were working.
But over seven years he gradually changed his mind, and in What We Owe The Future, Will argues that in fact there are clear ways we might act now that could benefit not just a few but all future generations.
He highlights two effects that could be very enduring: “…reducing risks of extinction of human beings or of the collapse of civilisation, and ensuring that the values and ideas that guide future society are better ones rather than worse.”
The idea that preventing human extinction would have long-lasting impacts is pretty intuitive. If we entirely disappear, we aren’t coming back.
But the idea that we can shape human values — not just for our age, but for all ages — is a surprising one that Will has come to more recently.
In the book, he argues that what people value is far more fragile and historically contingent than it might first seem. For instance, today it feels like the abolition of slavery was an inevitable part of the arc of history. But Will lays out that the best research on the topic suggests otherwise.
For thousands of years, almost everyone — from philosophers to slaves themselves — regarded slavery as acceptable in principle. At the time the British Empire ended its participation in the slave trade, the industry was booming and earning enormous profits. It’s estimated that abolition cost Britain 2% of its GDP for 50 years.
So why did it happen? The global abolition movement seems to have originated within the peculiar culture of the Quakers, who were the first to argue slavery was unacceptable in all cases and campaign for its elimination, gradually convincing those around them with both Enlightenment and Christian arguments. If a few such moral pioneers had fallen off their horses at the wrong time, maybe the abolition movement never would have gotten off the ground and slavery would remain widespread today.
If moral progress really is so contingent, and bad ideas can persist almost without end, it raises the stakes for moral debate today. If we don’t eliminate a bad practice now, it may be with us forever. In today’s in-depth conversation, we discuss the possibility of a harmful moral ‘lock-in’ as well as:
- How Will was eventually won over to longtermism
- The three best lines of argument against longtermism
- How to avoid moral fanaticism
- Which technologies or events are most likely to have permanent effects
- What ‘longtermists’ do today in practice
- How to predict the long-term effect of our actions
- Whether the future is likely to be good or bad
- Concrete ideas to make the future better
- What Will donates his money to personally
- Potatoes and megafauna
- And plenty more
Get this episode by subscribing to our podcast on the world’s most pressing problems and how to solve them: type ‘80,000 Hours’ into your podcasting app. Or read the transcript below.
Producer: Keiran Harris
Audio mastering: Ben Cordell
Transcriptions: Katy Moore