I don't think it does, no, because the connection rests on a third, unstated premise, that "potential sentience" carries moral weight. I don't believe that it does, or could, because potential is not an actually-existing property of real things, it's an inference we make from what information we have available to us, describing possible future outcomes.But isn't the OP's point pretty much the same if Premise X is 'A foetus will, on the balance of probability, become a sentient being'? The point being that the conditions exist under which, more often than that, a foetus develops into something with what the OP is calling sentience, and that therefore the age of a foetus should logically be irrelevant, given that everpresent potential? Does Premise Y then not follow from that?
I don't think it does, no, because the connection rests on a third, unstated premise, that "potential sentience" carries moral weight. I don't believe that it does, or could, because potential is not an actually-existing property of real things, it's an inference we make from what information we have available to us, describing possible future outcomes.
It is possible, even probably, that a pregnant woman may carry the pregnancy to term. It is also possibly that she may terminate the pregnancy. Both possibilities remain unrealised until they actually happen, and as soon as one happens, the other collapses. Neither possess any sort of ontological primacy over the other.
On the contrary; it's not even 'cogito ergo sum', it's 'cogito ergo cogito'. By questioning our own sentience, we prove it.
I'm afraid I don't follow - which question is it begging? A sentient being is one that is aware of itself: by questioning whether we are aware of ourselves, we reveal to ourselves that we exist, and therefore gain knowledge of ourselves.
False premise. A foetus will only become a sentient being constant external intervention on the part of the mother, who must supply the foetus with nutrients and oxygen for it to survive and develop. If you remove a foetus from the womb and put it on a table, it won't continue to develop, it'll just die. Nothing remotely inevitable about it.
So, tripping at the first hurdle with that one.