You’re given a box with a set of dice in it. If you roll an even number, a person's life is saved. If you roll an odd number, someone else will die. Each time you shake the box you get $10. Should you do it?

A committed consequentialist might say, "Sure! Free money!" But most will think it obvious that you should say no. You've only gotten a tiny benefit, in exchange for moral responsibility over whether other people live or die.

And yet, according to today’s return guest, philosophy Prof Will MacAskill, in a real sense we’re shaking this box every time we leave the house, and those who think shaking the box is wrong should probably also be shutting themselves indoors and minimising their interactions with others.

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To see this, imagine you’re deciding whether to redeem a coupon for a free movie. If you go, you’ll need to drive to the cinema. By affecting traffic throughout the city, you’ll have slightly impacted the schedules of thousands or tens of thousands of people. The average life is about 30,000 days, and over the course of a life the average person will have about two children. So — if you’ve impacted at least 7,500 days — then, statistically speaking, you've probably influenced the exact timing of a conception event. With 200 million sperm in the running each time, changing the moment of copulation, even by a fraction of a second, will almost certainly mean you've changed the identity of a future person.

That different child will now impact all sorts of things as they go about their life, including future conception events. And then those new people will impact further future conceptions events, and so on. After 100 or maybe 200 years, basically everybody alive will be a different person because you went to the movies.

As a result, you’ll have changed when many people die. Take car crashes as one example: about 1.3% of people die in car crashes. Over that century, as the identities of everyone change as a result of your action, many of the 'new' people will cause car crashes that wouldn't have occurred in their absence, including crashes that prematurely kill people alive today.

Of course, in expectation, exactly the same number of people will have been saved from car crashes, and will die later than they would have otherwise.

So, if you go for this drive, you’ll save hundreds of people from premature death, and cause the early death of an equal number of others. But you’ll get to see a free movie, worth $10. Should you do it?

This setup forms the basis of ‘the paralysis argument’, explored in one of Will’s recent papers.

Because most 'non-consequentialists' endorse an act/omission distinction… post truncated due to character limit, finish reading the full explanation here.

So what's the best way to fix this strange conclusion? We discuss a few options, but the most promising might bring people a lot closer to full consequentialism than is immediately apparent. In this episode Will and I also cover:

• Are, or are we not, living in the most influential time in history?
• The culture of the effective altruism community
• Will's new lower estimate of the risk of human extinction
• Why Will is now less focused on AI
• The differences between Americans and Brits
• Why feeling guilty about characteristics you were born with is crazy
• And plenty more.

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Producer: Keiran Harris.
Audio mastering: Ben Cordell.
Transcriptions: Zakee Ulhaq.