“Future people count. There could be a lot of them. We can make their lives go better.”

That’s the central idea of What We Owe The Future, a provocative book by William MacAskill who’s an associate professor of philosophy at the University of Oxford. Even if you disagree with some of the points in this book, it will leave you thinking about the future in a completely different way. 

What We Owe The Future
By William MacAskill
Basic Books, New York, 2022

Future people count

MacAskill argues that the wellbeing of future people ought to be just as important as present people. At a personal level this seems pretty obvious. Most of us would agree our children and grandchildren are just as important as we are. But MacAskill asks us to think about way more people way farther into the future.

Suppose, he says, you’re walking along a hiking trail and you drop a glass bottle. It shatters but you don’t stop to pick up the shards. A few hours later, a child walks by, stumbles and falls onto one of those shards badly cutting her knee. You’re morally responsible for her injury, right? 

Now imagine the child falls a week after you dropped the bottle, not just a few hours after. You’re still responsible for her injury, right?

What if she falls a year later, or twenty years later? Would that distance in time somehow absolve you? 

Of course not.

MacAskill says that the same reasoning applies to people born hundreds or even thousands of years in the future.

Our actions, or lack of action, today carry moral implications regardless how far in the future the affected people may live. 

There could be a lot of them

There are 8 billion people alive today. A total of about 100 billion people have lived ever since Homo sapiens first emerged as a distinct species around 300,000 years ago.

How many people will be born in future? 

Well assuming humans hang around for the same length of time as other mammal species – about 1 million years on average – humans have roughly 700,000 years to go. If the population alive at any one time remains constant at today’s 8 billion, then MacAskill estimates an astonishing 80 trillion people have yet to be born.

We can make their lives go better

It might seem absurd to think that we today could have any impact at all on the lives of trillions of people living thousands of years from now, but MacAskill thinks we’re living in an unusual and critically important time. That’s because in the 21^st century, human society is highly connected and growing quickly.

Both economic and population growth are high by historical standards. MacAskill says that our current exponential growth rates are unsustainable, particularly over the longterm future he’s talking about. He’s not the only one; Vaclav Smil makes the same point in his monumental book Growth.

We’re also highly connected. We live in a single global civilization. People, goods, services and information flow all over the world despite our differences and our borders. This wasn’t true as recently as a few hundred years ago when Europeans didn’t even know the Americas existed

MacAskill thinks we should use this exceptional time to lay the foundations for trillions of people to experience better lives. He’s an advocate for longtermism, the idea that “positively influencing the longterm future is a key moral priority of our time.” [p. 4]  

What do we owe the future?

There are two things we can do to positively influence the longterm future:

• Increase the likelihood of humanity’s survival, in other words, increasing the chances that we don’t go extinct.
• Change the trajectory of human development towards better lives for the future.

The bulk of What We Owe The Future is about how to do these things. Or rather, it’s mainly about what we should not do. Most of the suggestions in this book – it’s wisely not very prescriptive – are about preventing things that could cause human extinction, and not doing things that could prevent the trajectory of human development from improving future lives.

MacAskill thinks the main threats to human existence are an asteroid strike, uncontrolled artificial intelligence, great power nuclear war, and manmade pandemics. He thinks this last one is the most concerning. 

Climate change is also serious threat, but he thinks it’s more likely to cause civilizational collapse rather than outright human extinction. Still bad!

Obviously any actions we can take now to prevent these things from happening will carry enormous benefits far into the future. 

To ensure a continuing positive trajectory for human development we need to avoid what he calls “value lock-in,” a state where societal values become fixed and unchangeable.

Our values evolve slowly. The abolition of slavery is an enormous positive development, yet it’s only in the last 150 years that slavery has come to be seen as morally outrageous, MacAskill says. We don’t know what aspects of today’s world will be considered moral outrages by future generations. Perhaps failure to act on climate change will be seen that way. Or maybe eating meat, or restricting the freedom of people to live anywhere on the planet they choose. The point is we need to ensure values can evolve over time to improve people’s lives.

MacAskill says that to avoid value lock-in we need to preserve political debate and the capacity for social and political experimentation. So he opposes establishment of a world government because the people who would inevitably end up controlling such a government would have no incentive for change, and would face no competition. 

Ultimately, he says, we need to do things that are clearly beneficial, like moving to clean energy, do things that increase our options for the future, like avoiding value lock-in, and do things that preserve our capacity to learn more, such as devoting more resources to research and development.

Unsolicited Feedback

What We Owe The Future is an extremely thought-provoking book. By showing us how to think so far into the future, MacAskill vastly expands our imagination of what humanity could be and how long we could last. Just as important, he gives us some philosophical tools for longterm decision-making.

I agree it’s critical for us to think about the longterm future, but I have a couple of reservations about the book.

There’s a certain amount of hubris embodied in this book. MacAskill isn’t the first author to claim that our current century is the most important in human history. Yuval Noah Harari says the same thing in Sapiens. I’m not so sure. We certainly are living at an important time, and we face some enormously consequential challenges this century, especially climate change. But will this be most important century in history? Let’s check back in a million years.

While it’s important to think longterm, we don’t have a great track record and I think a large dose of humility is called for. MacAskill’s recommendations are very general in nature, but I wonder if thinking so far into the future is all that helpful. The Iroquois have a principle of making decisions that consider the impacts on people seven generations into the future. That’s about 200 years from now. Maybe that’s far enough. Would we come to vastly different conclusions thinking about the impacts 200,000 years from now?

The book is also highly anthropocentric. It’s almost entirely about human wellbeing. MacAskill does devote some time to animal welfare, or at least mammal welfare, but his attempts to compare human and animal wellbeing weren’t convincing. To his credit, he says such comparisons are “fiendishly difficult.” He doesn’t address the issue of species extinction at all. If we have a moral obligation to reduce cruelty to animals, then don’t we have an obligation to prevent their extinction? Maybe the most impactful thing we could do to increase total wellbeing on the planet would be to improve animal wellbeing.

But none of these concerns detract from the overall message of the book. We have a moral obligation to think longterm, as far into the future as we possibly can, because our decisions today can have hugely impactful consequences for enormous numbers of people.

Thanks for reading.

Related Links

Three Sentences That Could Change the World — and Your Life
Interview with William MacAskill on The Ezra Klein Show podcast, August 9, 2022.