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It's quite tough doing good, even if you just focus on the interests of people who are

alive today. The calculations of what we should do get much more complicated if you include

the interests of everyone who might come into existence in the future. There could be

trillions of them before humans go extinct. Should we really worry about all of them?

Will Macaskill, a prominent defender of the movement known as Long Termism, thinks we should.

According to him, future people count just as much as those alive today.

William Macaskill, welcome to Philosophy Bites. Thanks so much for having me on. We're going

to talk today about long-termism. Short-termism is a well-known concept. What's long-termism?

Long-termism is the view that positively impacting the long-term future should be a key model

priority of our time. So it's about taking concern for future generations seriously and

appreciating just how much is at stake with the things that might happen in our lifetime

that could positively or negatively impact the lives of future generations.

Now in historical terms, planet Earth currently has a lot of people. There were 8 billion

of us, roughly 8 times the global population that existed in 1800. So there's been an enormous

increase in population. And obviously we have reasons to care about the welfare and interests

of the people alive today. But the long term is claims that we also have reasons to care

about people who aren't yet born. And that might be a much, much bigger number than 8 billion.

Yeah, that's exactly right. Because I think that humanity's life expectancy could be very

large indeed. If you consider the lifespan of a typical mammal species that's about a million

...