I care nothing for Jewish law on the matter. The case against abortion can be made entirely from natural law or it can be made from Christian theology.

[quote:3mlewvhq]My question is exactly that, when does the soul dwell within the child?[/quote:3mlewvhq]
When does ensoulment happen? Something lives because it possesses a soul (this is true for humans, plants, animals, etc). Without a soul, something is not alive (James 2:26). Since a child is alive from the moment of conception, it is ensouled at the moment of conception.

“Now we allow that life begins with conception because we contend that the soul also begins from conception; life taking its commencement at the same moment and place that the soul does” (Tertullian, [i:3mlewvhq]The Soul[/i:3mlewvhq] 27).

[quote:3mlewvhq]My rationality tells me “when the child enters the world” (out of the womb) but that is human understanding.[/quote:3mlewvhq]
I do not understand how that is a rational conclusion. Was Christ not God in the womb? Did God not know Jeremiah before he was born? Did not John the Baptist leap in the presence of his Lord?

Interestingly, ensoulment at birth leads into a form of Nestorianism. Mary did not give birth to God, she gave birth to only Jesus’s humanity. The divine soul then entered a human body.