This consideration is something I had never thought of before and blew my mind. Thank you for sharing.
Hopefully I can summarize it (assuming I interpreted it correctly) in a different way that might help people who were as befuddled as I was.
The point is that, when you have probabilistic weight to two different theories of sentience being true, you have to assign units to sentience in these different theories in order to compare them.
Say you have two theories of sentience that are similarly probable, one dependent on intelligence and one dependent on brain size. Call these units IQ-qualia and size-qualia. If you assign fruit flies a moral weight of 1, you are implicitly declaring a conversion rate of (to make up some random numbers) 1000 IQ-qualia = 1 size-qualia. If you assign elephants however to have a moral weight of 1, you implicitly declare a conversion rate of (again, made-up) 1 IQ-qualia = 1000 size-qualia, because elephant brains are much larger but not much smarter than fruit flies. These two different conversion rates are going to give you very different numbers for the moral weight of humans (or as Shulman was saying, of each other).
Rethink Priorities assigned humans a moral weight of 1, and thus assumed a certain conversion rate between different theories that made for a very small-animal-dominated world by sentience.
This consideration is something I had never thought of before and blew my mind. Thank you for sharing.
Hopefully I can summarize it (assuming I interpreted it correctly) in a different way that might help people who were as befuddled as I was.
The point is that, when you have probabilistic weight to two different theories of sentience being true, you have to assign units to sentience in these different theories in order to compare them.
Say you have two theories of sentience that are similarly probable, one dependent on intelligence and one dependent on brain size. Call these units IQ-qualia and size-qualia. If you assign fruit flies a moral weight of 1, you are implicitly declaring a conversion rate of (to make up some random numbers) 1000 IQ-qualia = 1 size-qualia. If you assign elephants however to have a moral weight of 1, you implicitly declare a conversion rate of (again, made-up) 1 IQ-qualia = 1000 size-qualia, because elephant brains are much larger but not much smarter than fruit flies. These two different conversion rates are going to give you very different numbers for the moral weight of humans (or as Shulman was saying, of each other).
Rethink Priorities assigned humans a moral weight of 1, and thus assumed a certain conversion rate between different theories that made for a very small-animal-dominated world by sentience.