Thanks for writing this up—I thought this was a very philosophically high-quality forum post, both in terms of its clarity and familiarity with the literature, and have given it a strong upvote!
With that said, I think you’ve been too quick in responding to the first objection. An essential part of the project is to establish the capacities for welfare across species, but that’s neither necessary or sufficient to make comparisons—for that, we need to know about actual levels of well-being for different entities (or, at least the differences in their well-being). But knowing about the levels seems very hard.
Let me quickly illustrate with some details. Suppose chicken welfare has a range of +2 to −2 well-being levels, but for cows it’s −5 to +5. Suppose further the average actual well-being levels of chickens and cows in agriculture are −1 and −0.5, respectively. Should we prevent one time-period of cow-existence or of chicken-existence? The answer is chicken-existence, all else equal, even though cows have a greater capacity.
Can you make decisions about what maximises well-being if you know what the capacities but not the average levels are? No. What you need to know are the levels. Okay, so can we determine what the levels, in fact, are? You say:
Of course, measuring the comparative suffering of different types of animals is not always easy. Nonetheless, it does appear that we can get at least a rough handle on which practices generally inflict the most pain, and several experts have produced explicit welfare ratings for various groups of farmed animals that seem to at least loosely converge
My worry is: what makes us think that we can even “get a least a rough handle”? You appeal to experts, but why should we suppose that the experts have any idea? They could all agree with each other and still be wrong. (Arguably) silly comparison: suppose I tell you a survey of theological experts reported that approximately 1 to 100 angels could dance on the head of a pin. What should you conclude about how many angels can dance on a pin? Maybe nothing. What you might want to know is what evidence those experts have to form their opinions.
I’m sceptical we can have evidence-based inter-species comparisons of (hedonic) welfare-levels at all.
Suppose hedonism is right and well-being consists in happiness. Happiness is a subjective state. Subjective states are, of necessity, not measurable by objective means. I might measure what I suppose are the objective correlates of subjective states, e.g. some brain functionings, but how do I know what the relationship is between the objective correlates and the subjective intensities? We might rely on self-reports to determine that relationship. That seems fine. However, how do we extend that relationship to beings that can’t give us self-reports? I’m not sure. We can make assumptions (about general relationship between objective brain states and subjective intensities) but we can’t check if we’re right or not. Of course, we will still form opinions here, but it’s unclear how one could acquire expertise at all. I hope I’m wrong about this, but I think this problem is pretty serious.
If well-being consists in objective goods, e.g. friendship or knowledge, it might be easier to measure those, although there will be much apparent arbitrariness involved in operationalising these concepts.
There will be issues with desire theories too either way, depending whether one opts for a mental-state or non-mental-state version, but that’s a further issue I don’t want to get into here.
Thanks for the comment. You’re right that realized welfare is ultimately what matters. My hope is that thinking about capacity for welfare will sometimes help inform our estimates of realized welfare, though this certainly won’t be true in every case. As an example of an instance where thinking about capacity for welfare does matter, consider honey bees. At any given time, there are more than a trillion managed honey bees under human control. Varroa destructor mites are a common problem in commercial hives. When a mite attaches to an adult bee, it slowly drains the bee’s blood and fat. (It might be comparable to a tick the size of a baseball latching on to a human.) How does this affect the bee’s welfare? If bees have a capacity for welfare roughly similar to vertebrates, it seems like in the long-run we can do a lot more good by focusing on honey bee welfare.
I believe that interspecies comparisons of welfare are extraordinarily difficult, but I think you are still too pessimistic about the prospect of making such comparisons. It’s true that on many views welfare will be constituted (in whole or in part) by subjective (i.e., private) states for which we don’t have direct evidence. But we can still use inference to the best explanation to justifiably infer the existence of such states. We only have access to our own subjective experiences, but we infer the existence of such states in other humans all the time. (Humans can give self-reports, but of course we can’t independently verify such reports.) I think we can do the same with varying degrees of confidence for nonhuman animals.
For a discussion of possible cross-species measures of animal welfare, see this paper by Heather Browning.
Happy to really get in the weeds of this issue if you want to talk more.
To fill out the details of what you’re getting at, I think you’re saying “the welfare level of an animal is X% of its capacity C. We’re confident of both X and C in the given scenario for animal A is high enough that it’s better to help animal A than animal B”. That may be correct, but you’re accepting that than you can know the welfare levels because you know the percentage of the capacity. But then I can make the same claim again: why should we be confident we’ve got the percentage of the capacity right?
I agree we should, in general, use inference to the best explanation. I’m not sure we know how to do that when we don’t have access to the relevant evidence (the private, subjective states) to draw inferences. If it help, trying putting on the serious sceptic’s hat and ask “okay, we might feel confident animal A is suffering more than animal B, and we do make these sort of judgement the whole time, but what justifies this confidence?”. What I’d really like to understand (not necessary from you—I’ve been thinking about this for a while!) is what the chain of reasoning is that would go into that justification.
But then I can make the same claim again: why should we be confident we’ve got the percentage of the capacity right?
I think even if we’re not confident, bounds on welfare capacity can still be useful. For example, if I know that A produces X net units of good (in expectation), and B produces between Y and Z net units of good, then under risk-neutral expected value maximization, X < Y would tell me that B’s better, and X > Z would tell me that A’s better. The problem is where Y < X < Z. And we can build a distribution over the percentage of capacity or do a sensitivity analysis, something similar to this, say.
Thanks for writing this up—I thought this was a very philosophically high-quality forum post, both in terms of its clarity and familiarity with the literature, and have given it a strong upvote!
With that said, I think you’ve been too quick in responding to the first objection. An essential part of the project is to establish the capacities for welfare across species, but that’s neither necessary or sufficient to make comparisons—for that, we need to know about actual levels of well-being for different entities (or, at least the differences in their well-being). But knowing about the levels seems very hard.
Let me quickly illustrate with some details. Suppose chicken welfare has a range of +2 to −2 well-being levels, but for cows it’s −5 to +5. Suppose further the average actual well-being levels of chickens and cows in agriculture are −1 and −0.5, respectively. Should we prevent one time-period of cow-existence or of chicken-existence? The answer is chicken-existence, all else equal, even though cows have a greater capacity.
Can you make decisions about what maximises well-being if you know what the capacities but not the average levels are? No. What you need to know are the levels. Okay, so can we determine what the levels, in fact, are? You say:
My worry is: what makes us think that we can even “get a least a rough handle”? You appeal to experts, but why should we suppose that the experts have any idea? They could all agree with each other and still be wrong. (Arguably) silly comparison: suppose I tell you a survey of theological experts reported that approximately 1 to 100 angels could dance on the head of a pin. What should you conclude about how many angels can dance on a pin? Maybe nothing. What you might want to know is what evidence those experts have to form their opinions.
I’m sceptical we can have evidence-based inter-species comparisons of (hedonic) welfare-levels at all.
Suppose hedonism is right and well-being consists in happiness. Happiness is a subjective state. Subjective states are, of necessity, not measurable by objective means. I might measure what I suppose are the objective correlates of subjective states, e.g. some brain functionings, but how do I know what the relationship is between the objective correlates and the subjective intensities? We might rely on self-reports to determine that relationship. That seems fine. However, how do we extend that relationship to beings that can’t give us self-reports? I’m not sure. We can make assumptions (about general relationship between objective brain states and subjective intensities) but we can’t check if we’re right or not. Of course, we will still form opinions here, but it’s unclear how one could acquire expertise at all. I hope I’m wrong about this, but I think this problem is pretty serious.
If well-being consists in objective goods, e.g. friendship or knowledge, it might be easier to measure those, although there will be much apparent arbitrariness involved in operationalising these concepts.
There will be issues with desire theories too either way, depending whether one opts for a mental-state or non-mental-state version, but that’s a further issue I don’t want to get into here.
Hi Michael,
Thanks for the comment. You’re right that realized welfare is ultimately what matters. My hope is that thinking about capacity for welfare will sometimes help inform our estimates of realized welfare, though this certainly won’t be true in every case. As an example of an instance where thinking about capacity for welfare does matter, consider honey bees. At any given time, there are more than a trillion managed honey bees under human control. Varroa destructor mites are a common problem in commercial hives. When a mite attaches to an adult bee, it slowly drains the bee’s blood and fat. (It might be comparable to a tick the size of a baseball latching on to a human.) How does this affect the bee’s welfare? If bees have a capacity for welfare roughly similar to vertebrates, it seems like in the long-run we can do a lot more good by focusing on honey bee welfare.
I believe that interspecies comparisons of welfare are extraordinarily difficult, but I think you are still too pessimistic about the prospect of making such comparisons. It’s true that on many views welfare will be constituted (in whole or in part) by subjective (i.e., private) states for which we don’t have direct evidence. But we can still use inference to the best explanation to justifiably infer the existence of such states. We only have access to our own subjective experiences, but we infer the existence of such states in other humans all the time. (Humans can give self-reports, but of course we can’t independently verify such reports.) I think we can do the same with varying degrees of confidence for nonhuman animals.
For a discussion of possible cross-species measures of animal welfare, see this paper by Heather Browning.
Happy to really get in the weeds of this issue if you want to talk more.
Thanks for the thoughtful reply!
To fill out the details of what you’re getting at, I think you’re saying “the welfare level of an animal is X% of its capacity C. We’re confident of both X and C in the given scenario for animal A is high enough that it’s better to help animal A than animal B”. That may be correct, but you’re accepting that than you can know the welfare levels because you know the percentage of the capacity. But then I can make the same claim again: why should we be confident we’ve got the percentage of the capacity right?
I agree we should, in general, use inference to the best explanation. I’m not sure we know how to do that when we don’t have access to the relevant evidence (the private, subjective states) to draw inferences. If it help, trying putting on the serious sceptic’s hat and ask “okay, we might feel confident animal A is suffering more than animal B, and we do make these sort of judgement the whole time, but what justifies this confidence?”. What I’d really like to understand (not necessary from you—I’ve been thinking about this for a while!) is what the chain of reasoning is that would go into that justification.
I think even if we’re not confident, bounds on welfare capacity can still be useful. For example, if I know that A produces X net units of good (in expectation), and B produces between Y and Z net units of good, then under risk-neutral expected value maximization, X < Y would tell me that B’s better, and X > Z would tell me that A’s better. The problem is where Y < X < Z. And we can build a distribution over the percentage of capacity or do a sensitivity analysis, something similar to this, say.