Only where it evidentially doesn't seem to exist.
Because of your demand that a physical trait must define personhood.
Perhaps "personhood" is not as metaphysical as you might want it to be?
You think it's physical? :AMR:
You think that the CNS and all its functions is an assertion?
Nope. Your demand that it defines personhood has no chance of being shown possible by evidence.
This is what happens when your ideas are question-begging nonsense, you start demanding that what you say about abstract ideas is true because a physical thing exists. Then when asked to show how the item carries your evidence, you return to your demand.
After conception there is only a fertilised egg, and eggs come before the chicken and human beings afaic.
"As far as you are concerned" is not evidence.
At conception, we have a human — evidence, good evidence, that there is a person. All we have against the idea is your demand that he needs a central nervous system.
Your assertions are only your assertions.
Nope. Evidence, remember?
At conception, there is a human being. You agree that the fertilized egg is human, remember?
Evidence. Not unsupported assertion.
Unsupported assertion would be to say he needs white skin to be a person. You demand a central nervous system.
No, I confer it when there seems to be evidence that it exists.
Question-begging nonsense. You confer personhood when there is evidence. What evidence? A central nervous system. Why that? Because I demand it.
You have no evidence — not can you ever hope to gain any — that a central nervous system brings personhood.
I've never suggest it's in anyway precise but at least while there is no CNS I can be pretty comfortable that no human being/person would have to take precedence over the wishes of the woman involved and what she chooses to do or not.
You need evidence, not a demand, to have a rational argument.
However, the problem is not your nonsense ideas. The problem is that your endgame is murder.
Remember, even after a baby has a detectable nervous system, you would still turn a blind eye if his mother chose termination.