TL;DR: We have ethical obligations not just towards people in the future, but also people in the past.

Imagine the issue that you hold most dear, the issue that you have made your foremost cause, the issue that you have donated your most valuable resources (time, money, attention) to solving. For example: imagine you’re an environmental conservationist whose dearest value is the preservation of species and ecosystem biodiversity across planet Earth.

Now imagine it’s 2100. You’ve died, and your grandchildren are reading your will — and laughing. They’re laughing because they have tiled over the earth with one of six species chosen for maximum cuteness (puppies, kittens, pandas, polar bears, axolotls, and buns) plus any necessary organisms to provide food.

Why paperclip the world when you could bun it?

Cuteness optimization is the driving issue of their generation; biodiversity is wholly ignored. They’ve taken your trust fund set aside for saving rainforests, and spent it on the systematic extinction of 99.99% of the world’s species. How would that make you, the ardent conservationist, feel?

Liberals often make fun of conservatives by pointing out how backwards conservative beliefs are. “Who cares about what a bunch of dead people think? We’ve advanced our understanding of morality in all these different ways, the past is stuck in bigoted modes of thinking.”

I don’t deny that we’ve made significant moral progress, that we’ve accumulated wisdom through the years, that a civilization farther back in time is younger, not older. But to strengthen the case for conservatism: the people in the past were roughly as intellectually capable as you are. The people in the past had similar thoughts, similar hopes, similar dreams to you. And there are a lot more people in the past than the present.

In The Precipice, Toby Ord describes how there have been 100 billion people who have ever lived; the 7 billion alive today represent only 7% of all humans to date.

Ord continues to describe the risks from extinction, with an eye towards why and how we might try to prevent them. But this got me thinking: assume that our species WILL go extinct in 10 years. If you are a utilitarian, whose utilities should you then try to maximize?

One straightforward answer is “let’s make people as happy as possible over the next 10 years”. But that seems somewhat unsatisfactory. In 2040, the people we’ve made happy in the interim will be just as dead as the people in 1800 are today. Of course, we have much more ability to satisfy people who are currently alive — but there may be cheap opportunities to honor the wishes of people in the past, eg by visiting their graves, upholding their wills, or supporting their children.

Even if you are purely selfish, you should care about what you owe the past. This is not contingent on what other people will think, not your parents and ancestors in the past, nor your descendants or strangers in the future. But because your own past self also lives in the past. And your current self lives in the past of your future self.