“Lately I’m getting the feeling that I came in at the end,” Tony Soprano tells his therapist at their first session, and it’s natural to feel the same about your place in human history: that these are the twilight years. Hundreds of millennia of human activity stretch back behind us – the stone age and the bronze age and the iron age, the ancient world, the middle ages and onwards, culminating in today – whereas our mental image of our species’ future tends either to be hazy or, in the event of an extinction-level catastrophe, terrifyingly short.
But there is another way to see things. Even if the world population were to fall by 90%, and if humans survive no longer than the average mammalian species, a million years in total, then 99.5% of all human experience has yet to be lived. If we can dodge the aforementioned catastrophe – a big “if”, obviously – then a staggeringly huge proportion of humanity’s time on Earth is almost certainly yet to come.
“Strange as it may seem, we are the ancients,” writes the Oxford University philosopher William MacAskill. “We live at the very beginning of history, in the most distant past.” When we contemplate our moral responsibility to future generations, if we contemplate it at all, it can seem mainly like a matter of leaving the planet habitable for a few stragglers left to come. In reality, it’s an opportunity to influence the fate of almost all the humans there will probably ever be.
Startling as such reflections are, you might imagine you know exactly what’s coming next from a book called What We Owe the Future: a worthy but depressing reminder that the world is heading to hell in a handcart, informing you it’s your duty to live a life of self-denial, spurning air travel and single-use plastics and fretting over every supermarket banana, all the while trying to suppress the suspicion that your sacrifices won’t make a blind bit of difference. You’d be wrong, though. MacAskill’s case for “longtermism” – “the idea that positively influencing the longterm future is a key moral priority of our time” – is overwhelmingly persuasive. But it’s also unapologetically optimistic and bracingly realistic: this is by some distance the most inspiring book on “ethical living” I’ve ever read. (It motivated me to make immediate changes to the amount and targets of my own charitable donations.) Readers seeking reinforcement of the idea that it’s intrinsically morally virtuous to spend your time wallowing in anguish about the future should look elsewhere; longtermism is much more exciting than that.
The first major surprise is that What We Owe the Future isn’t solely or even mainly about the climate. Partly that’s because MacAskill is cautiously upbeat here, pointing to increasingly ambitious climate pledges, due in large part to youth activism, along with the plummeting cost of renewable energies and other positive trends. But it’s also because of equally urgent yet far more neglected threats. One is that we lose control of innovations in artificial intelligence, whether to tyrants or terrorists or – once AI itself becomes better than humans at developing new forms of AI – to the machines themselves. Without urgent collective action now, there’s little reason to expect such runaway AI to act in the service of humanity; we might “share the fate of, say, chimpanzees or ants vis-a-vis humans: ignored at best and with no say over the future of civilisation.” The other is a bioweapon that could kill billions. “Experts I know,” writes MacAskill, terrifyingly, “typically put the probability of an extinction-level engineered pandemic this century at around 1%.”
Yet the other striking component of MacAskill’s worldview is that it isn’t merely a question of making the best of a bad job – of doing what we can to ensure that life for our successors isn’t entirely awful. We have the chance to bring about untold quantities of greater future happiness, too. Indeed, it’s our responsibility; drawing on the work of the philosopher Derek Parfit, he argues that “preventing the existence of a happy and flourishing life is a moral loss”. It’s better for an extra human to come into being than otherwise, assuming they reach a threshold level of happiness. This is the ultimate moral force of longtermism: we should save the climate, control AI and stop pandemics not only to prevent the suffering of current or imminent generations, but because the end of humanity would mean trillions of potential happy lives going unlived. (And those lives could be really happy. The best quality of life today would have been unthinkable even for kings or queens in centuries past – so what if we’re in a similar position with respect to future flourishing?)
It follows too that, all else being equal, we should want the world’s population to grow; we should want to colonise space, so that more and more lives can flourish; and (though MacAskill is no opponent of reproductive rights) we should see having children as a way of making a positive contribution to the future. The increasingly popular environmental argument against parenthood rests, obviously, on a pessimistic assumption about the role your potential children might play in helping to create a better world. But it also fails to reckon with the potential human happiness you’re removing from the future – your children’s happiness, and those of their children, and their children’s children.
The question, of course, is whether we can really do all that much to help the future billions, besides having kids. MacAskill is certain we’re uniquely placed to do so, because we live in an era of unprecedentedly rapid change that can’t last much longer. (For current economic growth to continue for “just ten millennia more”, we’d need to extract many trillion times the world’s current economic output from every single atom to which we had access.) So we have dizzyingly more power to influence the future than those after us are likely to possess. There are many specific and achievable things governments and corporations must do on AI, pandemic risk and decarbonisation – and that we must pressure them to do, through activism and voting.
It’s also imperative to focus on “moral lock-in”, because the norms we establish now are likely to persist for millennia. In one of the book’s most compelling chapters, MacAskill argues convincingly that there was nothing inevitable about the end of slavery. It wasn’t a given that everyone would eventually realise that ownership of others was wrong. Rather, societal circumstances permitted an eccentric band of Quakers to nurture their abolitionist ideas until they caught on. This is a powerful argument in favour of freedom of speech and viewpoint diversity: the moral advance arose not from society’s leaders pursuing the values they were confident were correct, but from a climate in which multiple and often marginal worldviews could flourish.
When it comes to individual action, though, MacAskill’s passion is clearly for the targeted financial contributions he champions as a co-founder of the “effective altruism” movement, detailed on the website Giving What We Can. He considers the focus on personal ethical lifestyle changes a “major strategic blunder”: it’s good to be a vegetarian, but giving $3,000 to the right clean energy charity will make vastly more difference to the climate, he argues, than a whole lifetime of not eating meat. Other lifestyle changes make even less difference, while cash donations to causes more neglected than the climate can make even more (because the marginal value of your contribution is bigger). The overall promise of this thrilling book is of a life both less burdened by ethical guilt – by beating yourself up over every choice of groceries or transportation – and much more effective at actually helping humanity. A life you truly enjoy, and in which you take that enjoyment seriously enough to want the same – or better – for billions more humans to come.
• What We Owe the Future: A Million-Year View by William MacAskill is published by Oneworld (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply.
