(The following was my response to a comment on Facebook about how people calling themselves pro-life view abortion as murder, the same as if a woman shot and killed her husband. I disagree with that analogy on many levels. I owe some hat-tips to a few people for some of the ideas expressed here. I’ll try to update if I can find those posts.)

Except that, in your hypothetical, it’s probably safe to assume that the woman’s husband was not physically occupying space inside her abdomen (no sex jokes, please). I understand that people think abortion is murder–I think they’re wrong, and I don’t think that simply calling it murder ends the conversation. The problem with calling it murder in a way that makes it equivalent to killing a separate, autonomous human being for whatever reason is this: if you are experiencing kidney failure, and I am the only known person on earth who is a match to you, no one can legally force me to give you one of my kidneys, whatever the medical consequences for you or the social consequences for me. The same goes for a blood transfusion or any other use of any part of my body. If I am brain-dead, but my kidney is viable for organ donation, no one can take my kidney unless I consented to be an organ donor. In short, I have complete and utter legal authority and control over how to use my body, even if it means that someone else dies. The alternative is that I could be forcibly anesthetized for kidney removal, resulting in a possible lifetime of medical complications against my will. From a legal standpoint, it doesn’t matter why I refuse to consent to organ donation. Calling abortion murder as though it is merely a decision to end the life of another person (and I disagree that an embryo or fetus is a person in that sense, but that’s a slightly different topic) ignores completely the fact that said embryo or fetus is occupying space inside another person’s body. No one can be compelled to donate a kidney, and no one can be compelled to give up their body for an embryo or fetus. Otherwise, a corpse has more bodily autonomy than a living pregnant person.

Now, at this point, the conversation usually (not always) turns to the circumstances of the pregnancy–i.e. the woman (or transgender man, or genderfluid person, and so forth) had sex, knowing that pregnancy is a possible result, etc. etc. The problem there is that you don’t know, unless you investigate the circumstances of the pregnancy, whether it was the result of willful sexual conduct or not, and even if it were not the result of voluntary behavior (e.g. rape), so what? You already said that you believe a fetus is a person with the right to life and so forth, so it shouldn’t make a difference how the pregnancy occurred. It’s just that telling a rape victim that they have to endure the multitude of difficulties presented by pregnancy seems morally abhorrent to many people. That shouldn’t matter if you truly believe what you originally said–so we come back to the beginning, and still have to contend with the fact that the pregnant person has bodily autonomy that still has not been recognized.

There are other arguments too, such as a right of self-defense if a pregnancy threatens someone’s health, but it still comes down to the right to bodily autonomy. Whatever you believe about an embryo’s or fetus’ rights, a separate, living, breathing human being–who was viewed as such up until the moment their pregnancy was discovered–is sitting right there, being ignored.