That is the well established definition; no need to assume it for the sake of argument.
However, "capable of feeling sensations" is defined in different ways and thus leads to the large differences in when people say a fetus is capable of feeling pain.
Is it when the nerve cells responsible for emitting pain signals develop? When a fetus is capable of responding to pain? Is it when the circuits develop to route those pain sigbals to the part of the brain associated with conscious perception of pain?
All of those thresholds are crossed at different stages of fetal development so which threshold you use will change the answer you give for "when does a fetus become sentient?"
Well, I don't think so. I like to think I've studied enough philosophy to be at least somewhat reasonably acquainted with the term, and it wasn't striking me as "well established." And I did a bit of googling yesterday that also seemed to suggest the "well established definition" being used here is not consistent with any of the normal definitions. And just now I consulted the Stanford Encyclopedia of Philosophy, and now I'm convinced it's not even remotely close to well established.
Maybe I'm wrong, but I haven't seen anything cited here to back that up, or even just an appeal to any informal, working understanding of the concept that makes me think "oh, of course, that's the definition." And normally I wouldn't ask for such a thing, except for the fact that, to me at least, a lot of people seem to be confidently wrong about what it is.
>Is it when the nerve cells responsible for emitting pain signals develop? When a fetus is capable of responding to pain? Is it when the circuits develop to route those pain sigbals to the part of the brain associated with conscious perception of pain?
I can't find a single source that doesn't align with the definition provided by moeris. It can be phrased in many ways but the underlying concept is well established. People who are unfamiliar with the words may confuse sentience with sapience, but they are quite distinct concepts and not interchangeable.
That last one makes some big assumptions given the adaptability and complexity of the brain, combined with our still limited understanding of it's inner workings. If I were to pick one, I would lean closer to the "capable of responding to pain" but really all of those criteria have flaws and serve more as heuristics than rigorous criteria. I purposly didn't take a stance in my original comment to avoid descending into uninteresting partisan bickering.
I think I agree with you that the definition provided by moeris is basically on track, and it accords with everything in the links you shared. I would also recommend you review the term as it exists in Stanford Encyclopedia of Philosophy.
So that's all good. However, you said something along the lines of "doesn't even require that there be consciousness" and merely "more than automatic" which struck me as not being quite right, and that is the idea that I wanted to challenge. I think all the links you shared make some reference or another to consciousness, which to me makes them different from "not requiring consciousness." So I'm not sure how you are looking at those links and seeing something that comports with "not requiring consciousness" and I'm also not seeing how your version of sentience comports either with those or what moeris said. I'm surprised you would look up and post all those links without noticing this, especially in a conversation where that's exactly the thing at issue.
At best, I think you could say, the heartland, normal, well established definition makes reference to some amount of conscious experience, and it is certain fringe definitions could maybe be read as not requiring that. And I think even that would be an exceptionally generous interpretation of the thing you are spuriously claiming is a "well established definition."
>That last one makes some big assumptions
I really don't think it does. It's not making any assumptions about brains, it's taking a position on what sentience means. Maybe brains do a lot of stuff, some of which falls within our idea of sentience, and some of which doesn't. Again, all the definitions you link to are about sensation against the backdrop of consciousness. Meanwhile, only the last of the three of your proposed options was clearly suggesting consciousness. So I don't understand what assumption you think I am or am not making about brains. I don't think the other two options agree with the dictionary definitions you linked to, so I'm not really sure you should be in a position of confidently declaring that those are a "well established definition."
However, "capable of feeling sensations" is defined in different ways and thus leads to the large differences in when people say a fetus is capable of feeling pain.
Is it when the nerve cells responsible for emitting pain signals develop? When a fetus is capable of responding to pain? Is it when the circuits develop to route those pain sigbals to the part of the brain associated with conscious perception of pain?
All of those thresholds are crossed at different stages of fetal development so which threshold you use will change the answer you give for "when does a fetus become sentient?"