The key point here is "just when does human tissue become a human person?”
You seem intent on avoiding the real point: if human beings have no unalienable human rights from the moment of conception, they have no such rights at all,
ever.
"The law does not provide that the act of abortion pertains to homicide, for there cannot yet be said to be a live soul in a body that lacks sensation..."--St Augustine
"The intellective soul i.e., true person is created by God at the completion of man's coming into being." -- St Thomas Aquinas
etc, etc…
You’re not doing yourself any favors here, cherry picking quotes out of context.
1,600 years ago Augustine didn't know that an unborn baby even existed before quickening, much less that it was capable of sensation, and it’s clear from his writings that if he knew what we know today he’d have had no doubt that unborn human beings are living souls.
St. Thomas plainly says, in your own quote, that human beings are true persons form the moment of conception.
The quote from McCartney is both irrelevant and deceptive. The Church has always very clearly and definitively taught that it is murder to intentionally kill an innocent human being, and it is a fact that the unborn child is an innocent human being.
The quotes of Maritain and Feldman merely parrot your own position, they have interesting personal opinions but their conclusion (that abortion is licit) is unsupportable.
The Scriptures are silent in defining when one becomes a person.
So what? There are many truths that Scripture doesn’t address; the purpose of Scripture is not to be a source of all philosophical and scientific truths. If you really don’t believe anything that’s not in Scripture, then you don’t believe much.
Wow...I'd say you shouldn't have an abortion if you feel that strongly about it…
That’s exactly what the American slaveowners said: “If you think it’s wrong to own slaves and kill them if you wish, then don’t do it.”
A Nazi may as well have said ”Wow, I’d say you shouldn’t gas 6 million Jews if you think that strongly about it”.
All human beings have human rights. Unborn children are innocent human beings. Abortion is murder. Someday you'll be ashamed that you ever thought otherwise.
I'm done here.