Alternatively, you might assume you actually already are a human, alien or chicken, have (and remember) experience with suffering as one of them, but are uncertain about which you in fact are. For illustration, let’s suppose human or alien. Because you’re uncertain about whether you’re an alien or human, your concept of suffering points to one that will turn out to be human suffering with some probability, p, and alien suffering with the rest of the probability, 1-p. You ground value relative to your own concept of suffering, which could turn out to be (or revised to) the human concept or the alien concept with respective probabilities.
Let H_H be the moral weight of human suffering according to a human concept of suffering, directly valued, and A_H be the moral weight of alien suffering according to a human concept of suffering, indirectly valued. Similarly, let A_A and H_A be the moral weights of alien suffering and human suffering according to the alien concept of suffering. A human would fix H_H, build a probability distribution for A_H relative to H_H and evaluate A_H in terms of it. An alien would fix A_A, build a probability distribution for H_A relative to A_A and evaluate H_A in terms of it.
You’re uncertain about whether you’re an alien or human. Still, you directly value your direct experiences. Assume A_A and H_H specifically represent the moral value of an experience of suffering you’ve actually had,[1] e.g. the moral value of a toe stub, and you’re doing ethics relative to your toe stubs as the reference point. You therefore set A_A = H_H. You can think of this as a unit conversion, e.g. 1 unit of alien toe stub-relative suffering = 10 units of human toe stub-relative suffering.
This solves the two envelopes problem. You can either use A_A or H_H to set your common scale, and the answer will be the same either way, because you’ve fixed the ratio between them. The moral value of a human toe stub, H, will be H_H with probability p, and H_A with probability 1-p. The moral weight of an alien toe stub, A, will be A_H with probability p and A_A with probability 1-p. You can just take expected values in either the alien or human units and compare.
We could also allow you to have some probability of being a chicken under this thought experiment. Then you could set A_A = H_H = C_C, with C_C representing the value of a chicken toe stub to a chicken, and C_A, C_H, A_C and H_C defined like above.
But if you’re actually a chicken, then you’re valuing human and alien welfare as a chicken, which is presumably not much, since chickens are very partial (unless you idealize). Also, if you’re a human, it’s hard to imagine being uncertain about whether you’re a chicken. There’s way too much information you need to screen off from consideration, like your capacities for reasoning and language and everything that follows from these. And if you’re a chicken, you couldn’t imagine yourself as a human or being impartial at all.
So, maybe this doesn’t make sense, or we have to imagine some hypothetically cognitively enhanced chicken or an intelligent being who suffers like a chicken. You could also idealize chickens to be impartial and actually care about humans, but then you’re definitely forcing them into a different normative stance than the ones chickens actually take (if any).
It would have to be something “common” to the beings under consideration, or you’d have to screen off information about who does and doesn’t have access to it or use of that information, because otherwise you’d be able to rule out some possibilities for what kind of being you are. This will look less reasonable with more types of beings under consideration, in case there’s nothing “common” to all of them. For example, not all moral patients have toes to stub.
Alternatively, you might assume you actually already are a human, alien or chicken, have (and remember) experience with suffering as one of them, but are uncertain about which you in fact are. For illustration, let’s suppose human or alien. Because you’re uncertain about whether you’re an alien or human, your concept of suffering points to one that will turn out to be human suffering with some probability, p, and alien suffering with the rest of the probability, 1-p. You ground value relative to your own concept of suffering, which could turn out to be (or revised to) the human concept or the alien concept with respective probabilities.
Let H_H be the moral weight of human suffering according to a human concept of suffering, directly valued, and A_H be the moral weight of alien suffering according to a human concept of suffering, indirectly valued. Similarly, let A_A and H_A be the moral weights of alien suffering and human suffering according to the alien concept of suffering. A human would fix H_H, build a probability distribution for A_H relative to H_H and evaluate A_H in terms of it. An alien would fix A_A, build a probability distribution for H_A relative to A_A and evaluate H_A in terms of it.
You’re uncertain about whether you’re an alien or human. Still, you directly value your direct experiences. Assume A_A and H_H specifically represent the moral value of an experience of suffering you’ve actually had,[1] e.g. the moral value of a toe stub, and you’re doing ethics relative to your toe stubs as the reference point. You therefore set A_A = H_H. You can think of this as a unit conversion, e.g. 1 unit of alien toe stub-relative suffering = 10 units of human toe stub-relative suffering.
This solves the two envelopes problem. You can either use A_A or H_H to set your common scale, and the answer will be the same either way, because you’ve fixed the ratio between them. The moral value of a human toe stub, H, will be H_H with probability p, and H_A with probability 1-p. The moral weight of an alien toe stub, A, will be A_H with probability p and A_A with probability 1-p. You can just take expected values in either the alien or human units and compare.
We could also allow you to have some probability of being a chicken under this thought experiment. Then you could set A_A = H_H = C_C, with C_C representing the value of a chicken toe stub to a chicken, and C_A, C_H, A_C and H_C defined like above.
But if you’re actually a chicken, then you’re valuing human and alien welfare as a chicken, which is presumably not much, since chickens are very partial (unless you idealize). Also, if you’re a human, it’s hard to imagine being uncertain about whether you’re a chicken. There’s way too much information you need to screen off from consideration, like your capacities for reasoning and language and everything that follows from these. And if you’re a chicken, you couldn’t imagine yourself as a human or being impartial at all.
So, maybe this doesn’t make sense, or we have to imagine some hypothetically cognitively enhanced chicken or an intelligent being who suffers like a chicken. You could also idealize chickens to be impartial and actually care about humans, but then you’re definitely forcing them into a different normative stance than the ones chickens actually take (if any).
It would have to be something “common” to the beings under consideration, or you’d have to screen off information about who does and doesn’t have access to it or use of that information, because otherwise you’d be able to rule out some possibilities for what kind of being you are. This will look less reasonable with more types of beings under consideration, in case there’s nothing “common” to all of them. For example, not all moral patients have toes to stub.