If I have understood scientism’s comments, they believe neither of the possibilities you list in your first paragraph.
I think they believe that whether or not a mind can take place on a non-brain substrate, our consciousness(es) cannot exist somewhere other than a brain, because they are currently instantiated in brains, and cannot be transferred (whether to another brain, or anything else).
This does not preclude some other mind coming to exist on a non-brain substrate.
Here is a thought experiment that might not be a thought experiment in the foreseeable future:
Grow some neurons in vitro and implant them in a patient. Over time, will that patient’s brain recruit those neurons?
If so, the more far-out experiment I earlier proposed becomes a matter of scaling up this experiment. I’d rather be on a more resilient substrate than neurons, but I’ll take what I can get.
I’m betting that the answer to this will be “yes”, following a similar line of reasoning that Drexler used to defend the plausibility of nanotech: the existence of birds implied the feasibility of aircraft; the existence of ribosomes implies the feasibility of nanotech… neurogenesis occurring during development and over the last few decades found to be possible in adulthood implies the feasibility of replacing damaged brains or augmenting healthy ones.
If I have understood scientism’s comments, they believe neither of the possibilities you list in your first paragraph.
I think they believe that whether or not a mind can take place on a non-brain substrate, our consciousness(es) cannot exist somewhere other than a brain, because they are currently instantiated in brains, and cannot be transferred (whether to another brain, or anything else).
This does not preclude some other mind coming to exist on a non-brain substrate.
Here is a thought experiment that might not be a thought experiment in the foreseeable future:
Grow some neurons in vitro and implant them in a patient. Over time, will that patient’s brain recruit those neurons?
If so, the more far-out experiment I earlier proposed becomes a matter of scaling up this experiment. I’d rather be on a more resilient substrate than neurons, but I’ll take what I can get.
I’m betting that the answer to this will be “yes”, following a similar line of reasoning that Drexler used to defend the plausibility of nanotech: the existence of birds implied the feasibility of aircraft; the existence of ribosomes implies the feasibility of nanotech… neurogenesis occurring during development and over the last few decades found to be possible in adulthood implies the feasibility of replacing damaged brains or augmenting healthy ones.
Yes, I agree with all of this.