Glen Whitman has pretty much all of the abortion analogies (all five of them) that enter the logical debate about the topic.

It’s an odd thing. I used to debate him quite frequently on a now-defunct website, and he caused me to change my position on what the legality of early-term abortion should be with analogy number five

The Negligent Driver. When you negligently or deliberately cause harm to another person, the law requires you to provide compensation, either with money or some kind of action. If your negligent driving puts a pedestrian in the hospital, you are liable for his medical bills. Likewise, one might argue, your sexual behavior creates the risk of placing a fetus in a very precarious situation. If so, you are liable for the fetus’s care during that time. This analogy emphasizes the responsibility of people for the risks they create, thereby dodging the previous analogy’s “no invitation” problem. The difficulty with this analogy comes from the definition of “harm.” Harm doesn’t mean being in a difficult situation – it means being in a worse situation than you would have been otherwise. Were it not for your reckless driving, the pedestrian would (in all likelihood) still be walking around, safe and sound. Were it not for the act of sex, the fetus would not exist at all. To sustain the claim that the act of sex creates a risk of harm to the fetus, you have to insist that existence in a dependent state is worse than sheer non-existence. If the act of sex constitutes a tort, it is the only tort I can think of that creates the very person it victimizes.

I’m the only person I know of who changes his mind on abortion due to a logical argument.