As Rachels admits, most actual cases of killing are morally worse than most actual cases of letting die. Rachels argues via the Bathtub Cases that the bare difference between killing and letting die doesn't always make a moral difference and that therefore the Doctrine of Killing and Letting Die is false. Explain why he thinks that these conditions justify paternalistic prevention of suicide but not paternalistic killing. Explain how the argument could be used to argue for a blanket prohibition against driving through an intersection without stopping. A fetus is an innocent human being.
Abortion is the killing of a fetus.
Therefore, abortion is prima facie wrong. There is no non-arbitrary dividing line between a zygote and the person it becomes. It is prima facie wrong to kill a person. Therefore, it is prima facie wrong to kill a zygote. The fetus is a person.