So asked Rick Warren. (Never heard of him until now. I don't watch TV.)
The answer is: when the brain is created. That's a vague time, a gray area. One brain cell isn't enough, but after there is a small group of them, things get vague. By "the brain" I mean it very conservatively to include anything that a significant number of reasonable an informed observers would call a brain. There is no fact of the matter here as to where a group of cells becomes a brain, so there is no use arguing about it. The point is that sometime early on in pregnancy a brain is created. After that time, killing the baby is murder.
Before there is a brain, there is nobody home. Afterwards, there is someone there. The alternatives to this position are two:
- Tooleyanism, the position of Michael Tooley, that human rights begin when the baby recognizes that he is a being with a future: a person. This position admittedly entails that infanticide is also permissible, as infants do not recognize themselves has having a future.
- Standard right-to-life: that rights kick in at conception.
Now, Tooleyanism (1) is untenable because it fails to acknowledge that infants and fetuses with a brain can recognize themselves as having a future; they are people. They simply need practice at doing this cognitive feat. Notice that people in comas or struggling to come fully out of comas also are in the same predicament as these babies, and they have rights.
The standard right-to-life position (2) is untenable because it attributes rights to groups of cells with no brain, mind, consciousness, desires, feelings, etc: the very early fetus. But there is no person or self of any kind inside of these beings. So, they can't have rights.