On "Effective altruism, risk, and human extinction" by Richard Pettigrew
Richard Pettigrew has written a new paper on existential risk:
semanticscholar.org | philarchive.org
The paper briefly examines the disturbing argument that one might be morally better off by bringing about the end of humanity and argues for why this argument might be faulty. I think that his reasoning is convincing.
Here is an excerpt.
A group of hikers make an attempt on the summit of a high, snow-covered mountain. The route they have chosen is treacherous and they rope up, tying themselves to one another in a line so that, should one of them slip, the other will be able to prevent a dangerous fall. At one point in their ascent, the leader faces a choice. She is at the beginning of a particularly treacherous section—to climb up it is dangerous, but to climb down once you’ve started is nearly impossible. She also realises that she’s at the point at which the rope will not provide much security, and will indeed endanger the others roped to her: if she falls while attempting this section, the whole group will fall with her, very badly injuring themselves. Due to changing weather, she must make the choice before she has a chance to consult with the group. Should she continue onwards and give the group the opportunity to reach the summit but also leave them vulnerable to serious injury, or should she begin the descent and lead the whole group down to the bottom safely?
She has climbed with this group for many years. She knows that each of them values getting to the summit just as much as she does; each disvalues severe injury just as much as she does; and each assigns the same middling value to descending now, not attaining the summit, but remaining uninjured. You might think, then, that each member of the group would favour the same option at this point—they’d all favour ascending or they’d all favour descending. But of course it’s a consequence of Buchak’s theory that they might all agree on the utilities and the credences, but disagreeon what to do because they have different attitudes to risk. In fact, three out of the group of eight are risk-averse in a way that makes them wish to descend, while the remaining five wish to continue and accept the risk of injury in order to secure the possibility of attaining the summit. The leaders knows this. What should she do?
It seems to me that she should descend. This suggests that, when we make a decision that affects other people with different attitudes to risk, and when one of the possible outcomes of that decision involves serious harm to those people, we should give greater weight to the preferences of the risk-averse among them than to the risk-neutral or risk-inclined. If that’s so, then it might be that the effective altruist should not only advise the risk-averse to donate to the Quiet End Foundation, but should advise everyone in this way, since the morally right choice is the one made with the epistemically ideal credences, the morally ideal utilities, and the risk- attitudes obtained by aggregating the risk attitude of all the people who will be affected by the decision in some way that gives most weight to the attitudes of the risk-averse.
Richard Pettigrew has not taught me for many years, and so he is more or less a stranger to me now. But I had fond memories of him while studying as an undergraduate. I particularly appreciated his deep understanding of mathematics and philosophy and the empathetic way in which he supported his students.
I am grateful that he is engaging seriously with a rather serious set of ideas.