Just achieving the definition of alive doesn't grant you power over other human beings. It is not personhood.

Ethics are more complicated than a black and white definition of when a magical boundary has been achieved.

I agree the personhood question is more complicated than the definition of life. And I agree that ethics are more complicated than just the definition of personhood.

However, regarding the question of personhood, I wonder, when does it begin?

Does it begin at birth? I think not, because a fetus a few days before birth is essentially no different from a newborn in terms of development and abilities. There's quite a wide variance in how soon or late a baby can be born and survive.

Does it begin some time between fertilization and birth? I think not, because that entire time is a period of continual growth. There's no instant where the fetus is suddenly transformed. The fetus is getting older, developing. Similar to how a born baby gets older and develops. If personhood were to begin in this stage, it would have to be gradual, meaning partial personhood for some period of time. But that doesn't make sense. How can someone be a partial person?

I'm not talking about a magical boundary. I'm talking about (a) a biological boundary, and (b) the question of personhood, neither of which are magic.