Hi Jesse and Anthony, thank you––regarding your second point, I think it's indeed a nonstarter, from a person-centered point of view, to make up a "counterpart" for Alice. One might think the same regarding your first point: The assumption that Alice's welfare is zero in B-worlds, where she does not exist, is made up. As Mogensen puts it (p. 1027): "We may believe, for example, that a person’s welfare level is defined in outcomes in which she does not exist, and that it takes a value of zero (Greaves & Cusbert, 2022; Holtug, 2001; Roberts, 2003). This would indeed undermine my argument. However, it is also a position that I find incredible, since I find it incredible that non-existent people have well-defined levels of any measurable quantity, be it height, weight, or welfare, any more than logic has a well-defined temperature."
If this is right, it immediately gets us out of the worry expressed in your first point: Alice is indeterminate between the options, so that she is bracketed out (i.e., she provides us with no contrastive reason to favor an option rather than another).
However, it seems to me that this cannot be right. Suppose Alice net-suffers terribly in A-worlds. Surely, this gives us a contrastive reason to choose B rather than A, as far as Alice is concerned. Pace Mogensen, I believe we should be able to get to this verdict without assuming that Alice's nonexistent welfare is literally zero in B-worlds: In the scenario where Alice exists (we choose A and x-risk is averted), she has a welfare-based perspective on how worlds where she doesn't exist compare/rank relative to the world where she exists and suffers, and the comparison prefers nonexistence. (In other words, Alice supplies a welfare-based objection against our choosing A, grounded in the welfare-based take she has on our choice in the scenario where she comes into being.)
So, we have an Alice-indexed contrastive reason not to choose A of the following two-dimensional magnitude: (p ∈ [0, 1]; her negative welfare, say -10, or perhaps [-20, 0)). This reason has a determinate direction (favoring B rather than A) but an indeterminate strength. Now suppose that, in choosing A, we also determinately save Mel from malaria, providing her with a +5 welfare benefit, say. Mel thus supplies a contrastive reason of determinate strength favoring A rather than B. The sum of contrastive reasons is now indeterminate, so that either choice is permissible.
This is the correct verdict, I think. Both intuitively and from person-centered "first principles," impartial altruists should not favor either option in this case. What we have here is one moral patient favoring A, another one opposing A, and the balance of their contrastive reasons being unclear. It makes sense, intuitively and theoretically, that either option should be permissible. (On scope-sensitive forms of altruism, this verdict may change depending on the number of people like Alice and the number of people like Mel involved in the case, as one would expect.)
It is important not to lose sight of the fact that overall indeterminacy is not to be avoided tout court. We should avoid it where, and only where, it does not actually obtain from an impartial altruistic point of view. Consider the following variation on the above case. Suppose our uncertainty regarding Alice is deeper: She might also have a net-happy life in A-worlds, who knows. In that case, Alice provides us with no contrastive reason to favor either option; if we "ask her," she's fine with either choice (given her welfare stakes and our credences). Assuming that, in choosing A, we determinately save Mel from malaria, impartial altruists should not reach a verdict of overall indeterminacy: Mel is not fine with either choice and should thus determine our overall verdict.
The empirical situation (regarding x-risk, various ways in which human survival may be realized, and s-risk) is, of course, complicated. My post does not address the question of what kinds of cases we happen to be facing in the actual world today. It aims to make a contribution to the prior conceptual, moral, and decision-theoretic questions.
Hi Jesse and Anthony, thank you––regarding your second point, I think it's indeed a nonstarter, from a person-centered point of view, to make up a "counterpart" for Alice. One might think the same regarding your first point: The assumption that Alice's welfare is zero in B-worlds, where she does not exist, is made up. As Mogensen puts it (p. 1027): "We may believe, for example, that a person’s welfare level is defined in outcomes in which she does not exist, and that it takes a value of zero (Greaves & Cusbert, 2022; Holtug, 2001; Roberts, 2003). This would indeed undermine my argument. However, it is also a position that I find incredible, since I find it incredible that non-existent people have well-defined levels of any measurable quantity, be it height, weight, or welfare, any more than logic has a well-defined temperature."
If this is right, it immediately gets us out of the worry expressed in your first point: Alice is indeterminate between the options, so that she is bracketed out (i.e., she provides us with no contrastive reason to favor an option rather than another).
However, it seems to me that this cannot be right. Suppose Alice net-suffers terribly in A-worlds. Surely, this gives us a contrastive reason to choose B rather than A, as far as Alice is concerned. Pace Mogensen, I believe we should be able to get to this verdict without assuming that Alice's nonexistent welfare is literally zero in B-worlds: In the scenario where Alice exists (we choose A and x-risk is averted), she has a welfare-based perspective on how worlds where she doesn't exist compare/rank relative to the world where she exists and suffers, and the comparison prefers nonexistence. (In other words, Alice supplies a welfare-based objection against our choosing A, grounded in the welfare-based take she has on our choice in the scenario where she comes into being.)
So, we have an Alice-indexed contrastive reason not to choose A of the following two-dimensional magnitude: (p ∈ [0, 1]; her negative welfare, say -10, or perhaps [-20, 0)). This reason has a determinate direction (favoring B rather than A) but an indeterminate strength. Now suppose that, in choosing A, we also determinately save Mel from malaria, providing her with a +5 welfare benefit, say. Mel thus supplies a contrastive reason of determinate strength favoring A rather than B. The sum of contrastive reasons is now indeterminate, so that either choice is permissible.
This is the correct verdict, I think. Both intuitively and from person-centered "first principles," impartial altruists should not favor either option in this case. What we have here is one moral patient favoring A, another one opposing A, and the balance of their contrastive reasons being unclear. It makes sense, intuitively and theoretically, that either option should be permissible. (On scope-sensitive forms of altruism, this verdict may change depending on the number of people like Alice and the number of people like Mel involved in the case, as one would expect.)
It is important not to lose sight of the fact that overall indeterminacy is not to be avoided tout court. We should avoid it where, and only where, it does not actually obtain from an impartial altruistic point of view. Consider the following variation on the above case. Suppose our uncertainty regarding Alice is deeper: She might also have a net-happy life in A-worlds, who knows. In that case, Alice provides us with no contrastive reason to favor either option; if we "ask her," she's fine with either choice (given her welfare stakes and our credences). Assuming that, in choosing A, we determinately save Mel from malaria, impartial altruists should not reach a verdict of overall indeterminacy: Mel is not fine with either choice and should thus determine our overall verdict.
The empirical situation (regarding x-risk, various ways in which human survival may be realized, and s-risk) is, of course, complicated. My post does not address the question of what kinds of cases we happen to be facing in the actual world today. It aims to make a contribution to the prior conceptual, moral, and decision-theoretic questions.