EA - Octopuses (Probably) Don't Have Nine Minds by Bob Fischer

Link to original articleWelcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Octopuses (Probably) Don't Have Nine Minds, published by Bob Fischer on December 12, 2022 on The Effective Altruism Forum.Key TakeawaysHere are the key takeaways for the full report:Based on the split-brain condition in humans, some people have wondered whether some humans “house” multiple subjects.Based on superficial parallels between the split-brain condition and the apparent neurological structures of some animals—such as chickens and octopuses—some people have wondered whether those animals house multiple subjects too.To assign a non-negligible credence to this possibility, we’d need evidence that parts of these animals aren't just conscious, but that they have valenced conscious states (like pain), as that’s what matters morally (given our project’s assumptions).This evidence is difficult to get:The human case shows that unconscious mentality is powerful, so we can’t infer consciousness from many behaviors.Even when we can infer consciousness, we can’t necessarily infer a separate subject. After all, there are plausible interpretations of split-brain cases on which there are not separate subjects.Even if there are multiple subjects housed in an organism in some circumstances, it doesn’t follow that there are always multiple subjects. These additional subjects may only be generated in contexts that are irrelevant for practical purposes.If we don’t have any evidence that parts of these animals are conscious or that they have valenced conscious states, then insofar as we’re committed to having an empirically-driven approach to counting subjects, we shouldn’t postulate multiple subjects in these cases.That being said, the author is inclined to place up to a 0.1 credence that there are multiple subjects in the split-brain case, but no higher than 0.025 for the 1+8 model of octopuses.IntroductionThis is the sixth post in the Moral Weight Project Sequence. The aim of the sequence is to provide an overview of the research that Rethink Priorities conducted between May 2021 and October 2022 on interspecific cause prioritization—i.e., making resource allocation decisions across species. The aim of this post, which was written by Joe Gottlieb, is to summarize his full report on the phenomenal unity and cause prioritization, which explores whether, for certain species, there are empirical reasons to posit multiple welfare subjects per organism. That report is available here.Motivations and the Bottom LineWe normally assume that there is one conscious subject—or one entity who undergoes conscious experiences—per conscious animal. But perhaps this isn’t always true: perhaps some animals ‘house’ more than one conscious subject. If those subjects are also welfare subjects—beings with the ability to accrue welfare goods and bad—then this might matter when trying to determine whether we are allocating resources in a way that maximizes expected welfare gained per dollar spent. When we theorize about these animals’ capacity for welfare, we would no longer be theorizing about a single welfare subject, but multiple such subjects.[1]In humans, people have speculated about this possibility based on “split-brain” cases, where the corpus callosum has been wholly or partially severed (e.g., Bayne 2010; Schechter 2018). Some non-human animals, like birds, approximate the split-brain condition as the norm, and others, like the octopus, exhibit a striking lack of integration and highly decentralized nervous systems, with surprising levels of peripheral autonomy. And in the case of the octopus, Peter Godfrey-Smith suggests that “[w]e should.at least consider the possibility that an octopus is a being with multiple selves”, one for central brain, and then one for each arm (2020: 148; cf. Carls-Diamante 2017, 2019, 2022).What follows is a high-level summary of my full report on...