[RobbyS]

The safer word is, after all, not individual but person. However, there is a deep-rooted prejudice, based on Cartesian philosophy I think, that personality is simply a function of the brain, which is supposed to generate thought independently of the rest of the body. That is also simplistic, but scientists love to oversimply things just as we all do.

[MHGinTN]

I wonder, do you know when the human spirit takes up residence with the alive embryo or fetal aged human organism? [Note please, I'm not asking about the soul of life, I am asking about the human spirit.] Do you know who might know the answer to this?

[Question_Assumptions]

Personhood is essentially the trickier question of when the human individual can't be casually killed by another human individual like a plant or animal. In my experience, it's easier to address the two as seperate issues than as a single issue, since one of the favorite tactics of abortion advocates is to confuse and flip between the two so that nothing can be nailed down. The issue of personhood is a bit more complex but boils down to there being only two non-arbitrary points where a human becomes a person -- fertilization and about two years of age. See Michael Tooley's (in)famous essay In Defense of Abortion and Infanticide for a good pro-abortion argument of why that's the case, though Tooley picks the wrong point to support abortion.