If, as seems likely, scientists conclusively show that either brains or neural architecture are the necessary conditions for conscious experience, then that would heavily downgrade the likelihood that some alternative mechanism exists to provide bacteria with consciousness.
One of the things I mention in the post is that whenever we’re looking at scientific findings, we’re imposing certain standards on what counts as evidence. But it’s actually not all that clear how we’re supposed to construct these standards in the case of first-person experiences we don’t have access to. Brains/neural architectures are categories we invent to put particular instances of “brains” and “neural architectures” in. They’re useful in science and medicine but that doesn’t mean referring to those categories with those boundaries automatically tells us everything to know about conscious experience/suffering.
What we’re really interested in is the category containing systems capable of suffering, and there are a number of different views on what sort of criteria identifies elements in this category: some people follow criteria that suggest only other humans are similar enough to be capable of suffering[1], some people follow criteria that suggest mammals are also similar enough, some people follow criteria that suggest insects are also similar enough. These views have us decrease our threshold for acceptable similarity.[2] One next step might be to extend criteria from the cell-to-cell signaling of nervous systems to the intracellular signaling of microrganisms. If we’re confident in/accept some of the other criteria, can we really rule out similar adjacent criteria? This seems difficult given how much uncertainty we have about our reasoning regarding consciousness and suffering[3] . We only need to assign some credence to the views that count some things we know of microbes as evidence of suffering (e.g., chemical-reactive movement, cellular stress responses, how microbes react to predators & associated mechanisms) -- in order to think that microorganism suffering is at least a possibility.
There’s a lot of subjective judgment in this. And scientists can’t escape it too. The evolution of human intuitions was guided by what’s needed for social relationships etc., not fundamental truths about what is conscious/what can suffer. Scientists also impose their standards on what counts as evidence of consciousness/suffering—but the standards are constructed with those intuitions! I discuss more in the section linked in the footnote. [3]
discover the mechanistic link between biochemistry and consciousness. It seems to me that this missing link is the main factor that leaves room for possible bacterial suffering.
(I actually I hold a physicalist (monist) view. I don’t think consciousness is something additional to physics. Dualism seems unlikely mostly given how science hasn’t found additional “consciousness stuff” over and above physical reality. My (very rough) approach to all this is that (some) physical processes (e.g. in the brain) can be said to be conscious experiences, under some interpretation/criteria. Although, I don’t mention this stuff in the post to be more theory-neutral (hence my describing things as physical ‘evidence of suffering’), which is okay since I think the post doesn’t really rely on physicalism being true)
Sure, that’s alright :)
One of the things I mention in the post is that whenever we’re looking at scientific findings, we’re imposing certain standards on what counts as evidence. But it’s actually not all that clear how we’re supposed to construct these standards in the case of first-person experiences we don’t have access to. Brains/neural architectures are categories we invent to put particular instances of “brains” and “neural architectures” in. They’re useful in science and medicine but that doesn’t mean referring to those categories with those boundaries automatically tells us everything to know about conscious experience/suffering.
What we’re really interested in is the category containing systems capable of suffering, and there are a number of different views on what sort of criteria identifies elements in this category: some people follow criteria that suggest only other humans are similar enough to be capable of suffering[1], some people follow criteria that suggest mammals are also similar enough, some people follow criteria that suggest insects are also similar enough. These views have us decrease our threshold for acceptable similarity.[2] One next step might be to extend criteria from the cell-to-cell signaling of nervous systems to the intracellular signaling of microrganisms. If we’re confident in/accept some of the other criteria, can we really rule out similar adjacent criteria? This seems difficult given how much uncertainty we have about our reasoning regarding consciousness and suffering[3] . We only need to assign some credence to the views that count some things we know of microbes as evidence of suffering (e.g., chemical-reactive movement, cellular stress responses, how microbes react to predators & associated mechanisms) -- in order to think that microorganism suffering is at least a possibility.
There’s a lot of subjective judgment in this. And scientists can’t escape it too. The evolution of human intuitions was guided by what’s needed for social relationships etc., not fundamental truths about what is conscious/what can suffer. Scientists also impose their standards on what counts as evidence of consciousness/suffering—but the standards are constructed with those intuitions! I discuss more in the section linked in the footnote. [3]
(I actually I hold a physicalist (monist) view. I don’t think consciousness is something additional to physics. Dualism seems unlikely mostly given how science hasn’t found additional “consciousness stuff” over and above physical reality. My (very rough) approach to all this is that (some) physical processes (e.g. in the brain) can be said to be conscious experiences, under some interpretation/criteria. Although, I don’t mention this stuff in the post to be more theory-neutral (hence my describing things as physical ‘evidence of suffering’), which is okay since I think the post doesn’t really rely on physicalism being true)
Similar enough to oneself—the only system that we’re absolutely sure can suffer
What about more “fundamental” differences? I respond to that in the Counterarguments subsection.
See Appendix: Factors affecting how we attribute suffering