Rothbard has seized upon an important but accidental feature of human procreation, namely, that the child is attached to the mother.
One consequence is that a Proper Rothbardian abortion would proceed as follows: (a) the child is carefully extracted from the womb, alive and well, placed near the mother, and then slowly dies from exposure and lack of nutrients, if no one is willing to pick it up.
But don’t actual abortions occur in a different way, viz., (b) the child is killed inside the womb, and the remains are sucked out? Rothbard himself writes that “a parent does not have the right to aggress against his children,” but do not most abortions do exactly that?
Furthermore, praxeologically, (a) and (b) constitute a distinction without a difference. The child dies either way, and the parents go home happy either way. A non-philosopher may well ask what the big deal is in this hair-splitting.
Thus, the question of whether unborn children have rights does not become irrelevant even if we use Rothbard’s approach.
Here’s the formal argument.
(1): Rothbard: “a parent does not have the right to aggress against his children.”
(2) According to a non-philosopher, either both (a) and (b) are permissible or neither (a) nor (b) is permissible.
(3) A pro-life person would disallow both; a pro-choice libertarian would seem to be committed to disallowing (b) only.
(4) Only the pro-life position appears at first glance to be consistent.
Here’s another illustration. Let Smith be trespassing on Jones’ property. (i) = Jones’ bouncers escort Smith out. (ii) = Jones kills Smith and dumps his corpse in a public waste disposal site.
Clearly, these are very different. (i) is obviously Ok, (ii) is obviously not.
But in the case of abortion, (a) and (b) are almost indistinguishable. What is Ok and what is not Ok is no longer “obvious.”
A clue toward a Rothbardian reply can be found in his debate with Jim Sadowsky:
“Sadowsky is worried about ejecting a stowaway on an airplane. Yes, I suppose that would be ‘overkill,’ to coin a pun. But the point here is that, just as an assault on someone’s body is a more heinous crime than the theft of his property, so the trespassing on or within a person’s body is a far more heinous trespass that merely strolling on his land or stowing away on an aircraft. For the crime of trespassing within a person’s body, any means necessary to evict the trespasser should be legitimate.”
Any means, including (b). So, (b) is legitimate, if it is the only way to abort. Hence, the argument fails at (3). The parent is not aggressing against the fetus but is defending herself. If Smith, instead of walking on Jones’ land, was a demon who tried to possess Jones’ body, then surely, Jones would be justified in killing the demon.
On this reasoning, abortion of type (a) is permissible for the less controversial (in libertarian circles) reason of the rights of the mother to her body.
Abortion of type (b) is permissible for perhaps somewhat more dubious reason of self-defense: the mother is defending herself against a dangerous parasite who is preying on her, and if she has to kill it to get it out, then so be it.