What is the property that makes those cells not concious? As you explain, there is some sort of difference there but it's not clear how that works.
The only kind of evidence we have that anything is conscious is self reporting from other humans. For many vertebrates it seems plausible they have some level of consciousness based on observed behavior, but we don't really know.
I'd say the burden of proof lays squarely on the side of proving that anything besides an advanced CNS is involved in consciousness. I see no reason anyone should have to disprove the existence of consciousness anywhere outside of a fairly advanced brain.
> I see no reason anyone should have to disprove the existence of consciousness anywhere outside of a fairly advanced brain.
There's a fairly big moral reason. Unless we can know what is concious and what is not, it's only right to be on the safe side and treat all organisms as if they are concious. How advanced should the CNS be before there's an obligation to not cause pain for an organism? (should we care about chickens in cages?)
And I think pain implies conciousness. A calculator can't feel pain because it experiences nothing. To feel pain a chicken must experience something, it must be concious.
My take on the assessment of pain is that any entity with some self sustained direction (in life) will be able too suffer or feel pain when faced with sensations that signal an obstruction to that direction. If the entity is able to self correct the path after such sensory input, I claim that the entity can experience pain.
With that in mind: A calculator has no self sustained direction. And no sensory input to help with self correction either. So it naturally cannot feel pain.
A chicken has a self sustained direction. It lives (moves on its own) and at least want to continue to do so. It also has the ability to self correct when given sensory input. So it can feel pain, and you can (given the reasoning above) be cruel to chickens. Even without an assessment of whether the chicken is conscious or not.
To be conscious, to go into that as well, is in my book to be able to use reason and to be able to reflect on things. So that new sensory inputs are created and assessed based on other already experienced sensory inputs. I.e. to be able to self adjust ones path (in life) seemingly, from an external observer, without any new sensory input.
With that definition one should be able to construct experiments with chickens to decide whether they are conscious or not, or merely acting subconsciously, autonomously.
With that definition of consciousness it should also be possible to define an AI that is conscious. And given the definition of pain above, it should also be possible to inflict pain on (and be cruel to) an AI. The morality of inflicting pain on different subjects is a different story though... :-)
Cheers