This paper was published as a GPI working paper in November 2024 and is forthcoming in Ergo.
Abstract
On person-affecting views in population ethics, the moral import of a person’s welfare depends on that person’s temporal or modal status. These views typically imply that – all else equal – we’re never required to create extra people, or to act in ways that increase the probability of extra people coming into existence.
In this paper, I use Parfit-style fission cases to construct a dilemma for person-affecting views: either they forfeit their seeming-advantages and face fission analogues of the problems faced by their rival impersonal views, or else they turn out to be not so person-affecting after all. In light of this dilemma, the attractions of person-affecting views largely evaporate. What remains are the problems unique to them.
Introduction
Suppose that you find yourself with a choice. You can either:
(a) Donate $4500 to the Against Malaria Foundation (AMF).
Or:
(b) Donate $4500 to the Nuclear Threat Initiative (NTI).
You’re confident that donating to AMF would save a child from dying of malaria. You’re also reasonably sure that this child would go on to live an additional 70 years of good life. On the other hand, you estimate that donating to NTI would increase the probability that humanity survives the coming century by about one in-ten-quadrillion (10−16). And you expect that if humanity survives the coming century, the future will contain one-hundred-quadrillion (1017) good lives, each lasting around 70 years. Where should you send your money?
Here’s a quick argument for NTI. By donating to AMF, you’d cause about 70 additional years of good life to be lived, in expectation. By donating to NTI, you’d cause about 700 additional years of good life to be lived, in expectation. It’s better to add 700 years of good life than it is to add 70 years of good life. Therefore, you should send your money to NTI.
There are many ways to resist this quick argument, but perhaps the most natural way is to claim that the years of good life that might result from your NTI donation just don’t matter in the same way as the years of good life that would result from your AMF donation. By donating to AMF, you gift 70 more years to a person who actually exists, who will exist regardless of your decision, and who exists right now. The same can’t be said of your donation to NTI. The vast majority of those additional years would accrue far in the future: to people who do not and need never exist.
This is a person-affecting response to the quick argument. On person-affecting views in population ethics, the moral import of a person’s welfare depends on that person’s temporal or modal status. These views typically imply that – all else equal – we’re never required to create extra people, or to act in ways that increase the probability of extra people coming into existence.
The allure of person-affecting views is partly in their foundations. These views often have their start in two claims that many find intuitive: (1) the Person-Affecting Restriction: an outcome can’t be better than another unless it’s better for some person, and (2) Existence Anticomparativism: existing can’t be better for a person than not existing.
However, another big draw of person-affecting views is their upshots. These views avoid some well-known problems faced by their rival impersonal views. Consider expected total utilitarianism: one prominent impersonal view. It implies that there are cases in which we’re required to create new happy people rather than help existing people, cases in which we’re required to make great sacrifices to create new people with lives barely worth living, and cases in which we’re required to make great sacrifices to slightly reduce the chance of near-term human extinction. Person-affecting views mostly avoid these problems, and that might seem like a significant point in their favour.
In this paper, I argue that these advantages are largely illusory. Using Parfit-style fission cases, I construct a dilemma for person-affecting views: either these views violate the spirit of the Person-Affecting Restriction, or else they imply fission analogues of the problems that blight impersonal views. These fission analogues are about as troubling as the original problems, and so they undermine much of the motivation for preferring person-affecting views to impersonal views. Considering the objections unique to person-affecting views, we should prefer impersonal views on balance.
Rejecting person-affecting views doesn’t immediately commit us to NTI over AMF. There are many ways to resist the quick argument. But – as I hope to show in this paper – the most natural line of resistance isn’t as attractive as it might first seem.
A different version of (5), in response to Benign A-Fission, could be a rule that treats Lefty as non-extra and Righty as extra in Split B — maybe for basically the reasons you give for Split B over No Split —, and one of Lefty or Righty as non-extra in Split C. Then you'd choose Split B among the three options.
One incomplete rule that could deliver this result is the following:
If all the splits have non-negative welfare, treat one with the highest welfare as non-extra, and treat the others as extra.
So, No Split gives Anna 80 welfare, Split B, 10+90=100 welfare and Split C, 10+60=70 welfare. Split B is best.
This doesn't say what to do about splits with negative welfare. Two options:
We might also consider decreasing marginal value to additional splits beyond the highest positive (and worst negative) welfare one, instead of totally ignoring them. Maybe the highest welfare one gets full weight, the second highest gets weight r,0<r<1, the third highest gets r2, ..., the n-th highest gets rn−1. This bounds the weighted sum of welfare in the splits by ∑∞n=0rn=11−r times the welfare of the best off split. They still count for something, but we could avoid Repugnant Fission.