Hilary Greaves on Pascal’s mugging, strong longtermism, and whether existing can be good for us

This is a cross-post of an episode I helped host of the 80,000 Hours Podcast, with Rob Wiblin and Oxford philosopher Hilary Greaves. It was one of my favorite episodes out of those I helped out with in 2020. Please check it out, and enjoy!

If you think that being born with a good life is better for the people in question then not being born, then it’s really hard not to be led to something like a totalist population axiology, where in particular you’re going to think that if the future would be good in the absence of extinction, then premature human extinction is an astronomically bad thing.

Hilary Greaves

Had World War 1 never happened, you might never have existed.

It’s very unlikely that the exact chain of events that led to your conception would have happened if the war hadn’t — so perhaps you wouldn’t have been born.

Would that mean that it’s better for you that World War 1 happened (regardless of whether it was better for the world overall)?

On the one hand, if you’re living a pretty good life, you might think the answer is yes – you get to live rather than not.

On the other hand, it sounds strange to say that it’s better for you to be alive, because if you’d never existed there’d be no you to be worse off. But if you wouldn’t be worse off if you hadn’t existed, can you be better off because you do?

In this episode, philosophy professor Hilary Greaves – Director of Oxford University’s Global Priorities Institute – helps untangle this puzzle for us and walks me and Rob through the space of possible answers. She argues that philosophers have been too quick to conclude what she calls existence non-comparativism – i.e, that it can’t be better for someone to exist vs. not.

Where we come down on this issue matters. If people are not made better off by existing and having good lives, you might conclude that bringing more people into existence isn’t better for them, and thus, perhaps, that it’s not better at all.

This would imply that bringing about a world in which more people live happy lives might not actually be a good thing (if the people wouldn’t otherwise have existed) — which would affect how we try to make the world a better place.

Those wanting to have children in order to give them the pleasure of a good life would in some sense be mistaken. And if humanity stopped bothering to have kids and just gradually died out we would have no particular reason to be concerned.

Furthermore it might mean we should deprioritise issues that primarily affect future generations, like climate change or the risk of humanity accidentally wiping itself out.

This is our second episode with Professor Greaves. The first one was a big hit, so we thought we’d come back and dive into even more complex ethical issues.

We also discuss:

• The case for different types of ‘strong longtermism’ — the idea that we ought morally to try to make the very long run future go as well as possible

• What it means for us to be ‘clueless’ about the consequences of our actions

• Moral uncertainty — what we should do when we don’t know which moral theory is correct

• Whether we should take a bet on a really small probability of a really great outcome

• The field of global priorities research at the Global Priorities Institute and beyond
  
  Go to the episode page or search 80000 Hours in your podcasting app and find episode #86.