A non-religious, libertarian case against abortion.
When a woman conceives a child, mother and child become joint owners of many organs. The woman has voluntarily (unless she was raped), and temporarily, granted joint ownership of her organs to her unborn child. The fetus, and the maternal organs it depends on and is integrated with (especially through the umbilical cord), is in effect one organism and one human being, just as the mother’s and those same organs is another human being. The genetic differences have no bearing on the matter; what matters is organic integration. When the baby is born, it sheds its shared organs, and upon the umbilical being cut, becomes a completely separate human being.
To abort the baby — to fatally expel the baby before it comes to term — would be to destroy the baby by depriving it of the use of its body (its shared organs); in other words, it would be murder.
Even if the above is not accepted, and the mother’s organs are not considered temporarily part of the baby’s body, abortion would still be unjust.
To restate a common thought experiment, if you were to invite someone onto your private plane, and then decide she is no longer welcome mid-flight and kick her off, that would be murder. This is because, to invite someone for a plane ride is to implicitly take on, for the duration between take-off to landing, a limited trusteeship or bailment of their bodies. You have voluntarily taken in trust a certain degree of safekeeping of the person’s body. If you were to agree to transport the person’s antique dresser in the plane, and then change your mind and dump it mid-flight to get better fuel-efficiency, you will have criminally destroyed her property. Similarly, if you dump the person herself for better mileage, you will have criminally destroyed her body: murdered her.
Or say that a tall man offered a boy who couldn’t swim a shoulder-ride across a pond. After reaching a point where the water is deeper than the boy is tall, the man has implicitly taken on trusteeship of his body. If the man were to change his mind in deeper water and drop the boy to drown, he would be murdering him.
Similarly, to conceive a child is to implicitly and voluntarily (outside of rape) take on, for the duration between conception and birth, a trusteeship or bailment of the unborn baby’s body. The baby is the beneficiary of this trust or bailor of this bailment. To abort the baby because you no longer want her to drain your body’s resources would be akin to agreeing to transport a person on your plane or across a pond on your shoulders, and then drop her mid-way to plummet or drown, because you no longer want her to drain your plane’s/shoulders’ resources.
Walter Block has objected to this kind of argument by saying that you can’t contract with someone who doesn’t exist yet, and therefore the act of conception cannot be an implicit contract. However, whether you call it a “contract” or not, there is nothing unreasonable about legally binding transfers to be fulfilled in the future involving people who can be specified according to certain criteria, but who do not exist yet. For example, in many U.S. states, children posthumously conceived through in vitro fertilization can inherit property from the deceased parent. Similarly, a voluntary act of conception is taking on trusteeship of whichever human being results from the act.
Such trusteeship continues after birth as well. The child’s body is in the mother’s and father’s trust to be restored to the child herself when she has developed enough to be able to claim it, or to be transferred to another responsible adult’s guardianship. Thus, both biological parents must at least protect her from physical harm and intense suffering until they deliver her to someone who will care for her. To expose a child in the wilderness, in a dumpster, or in a corner of a room, would be to criminally allow the destruction of something you have voluntarily taken trusteeship of: a child’s body and life.
POSTSCRIPT: Walter Block also accepts that parents are obligated to at least “deliver the child to the church steps.” He only accepts a similar obligation for unborn children to a limited extent. The mother must only “evict” a viable child in as safe a manner as possible. However, if the baby is not viable outside of the womb when the mother wants to evict her, then, according to Block, abortion is acceptable.
However, Block’s distinction between acceptable “church steps” obligations and unacceptable “parasite-host” obligations with regard to maintaining the life of the child is arbitrary and untenable. The trip to the “church steps” or to the clinic specializing in premature birth takes time and resources; so too does taking the baby to the point of extra-womb viability or to full term. The latter simply take more time and more resources. Drawing the line at one time/resource commitment and not another is arbitrary.
Also published at Medium.com: