Wednesday, July 15, 2015

Don't Kill Me: I Was Once a Fetus

Here is a fairly close rendering of Alexander Pruss's brilliantly simple argument against abortion put in the first person.  (I accept full responsibility for any errors, and part of what I say might go slightly beyond what Pruss says in the particular article to which I linked).

Let L name the living organism that came into being as a result of the sperm from my father fertilizing the ovum of my mother nine-months before I was born.
Let A name the only animal sitting in my chair typing: Me.
(1) L never died.
(2) If L never died, then L still exists.
(3) If L still exists, then L is the same animal as A.
(4) Therefore, L is the same animal as A (from 1,2,3).
(5) Therefore, I am the same animal as L (Leibniz's Law).
(6) If I am the same animal as L, then I was once a fetus (embryo, etc).
(7) Therefore, I was once a fetus (from 5,6).
(8) If I was once a fetus, then only reasons which would justify killing me would justify killing the fetus.
(9) Therefore, only reasons which would justify killing me would justify killing the fetus (from 7, 8).
(10) There would have been no sufficient reasons which justified killing me when I was in the womb.
(11) Thus, there would have been no sufficient reasons which justified killing the fetus in the womb (from 9,10).**

*This allows for at least materialism about animals as well as hylomorphism. It's hard to see how it fits with substance dualism wherein I am identical with an immaterial soul.  But then for those who think that they are identical to an immaterial soul, the best move might be to go with Idealism; and Idealism fits much better with religious monotheism than it does with naturalism.

**Pruss's argument does not explicitly go so far as to say that there are no justifiable reasons for abortion.  His argument is focused on the fact that if one killed the fetus one would be killing my mother's fetus, that is, one would be killing me.


  1. Pruss's argument is great!

    It looks to me like the premises that a pro-choice person would attack are (2), (8), or (10). (2) assumes endurantism with respect to the persistence of objects. But, I'd love it if pro-choicers were pushed to adopt perdurantism! Try convincing the public that abortion is okay because there is no "me" that endures from one moment to the next!

    With respect to (8) and (10), the pro-choicer would either have to give a reason why it is okay to kill my fetus that does not apply to me now which WAS NOT ad hoc, or say that it is okay to kill me now. Neither way of argument will be rationally compelling.

  2. Spear,

    I don't know if (2) assumes endurance or not. It might. Pruss has some neat arguments against perdurance, though. And of course there are others.

    (8) just restates the identity claim again, though, with "fetus" substituting for "living organism." We shouldn't read "fetus" in the technical, clinic sense of a certain stage of development. It's just there for heuristic purposes.

    (10) will definitely be questioned. In P.Churchland's well known article, she assumes we're killing a human/person but argues that at least in cases of rape it's justified. And just to be clear, Pruss's focus is on an argument for the conclusion that "I was once a fetus" and doesn't focus much on the morality issues. I can't recall if his argument in the article to which I linked above makes that further move (though I know he would agree with it.)

    Another move is to deny the stipulation prior to the argument that I am an animal. This will be tough for most, since I think most naturalists are full-on materialists and thus materialist-animalists ("animalism" almost always refers to reductive materialist-animalism, but, as I note, hylomorphists think that I'm an animal though I'm part immaterial) . One could, though, say that I am not animal but I am a person which "emerges" and is co-located with the animal to which I'm not identical. But then I think one is appealing to magic more mysterious than God's infusing a soul.

  3. It's not obvious that (2) assumes endurantism, but I think it does. Perdurantism essentially gives up on looking for an answer to the challenge of accounting for objects persisting, saying that they do not. Now, Your definition of L is pretty non-commital. Assume perdurantism for an moment. L refers to one of two things. It either refers to a) a whole object, consisting of all the temporal parts from the moment of the union of the sperm and the egg to the last temporal part, whether that be the part right before death or whenever, or (b) the temporal part that came into existence at the moement of the union of the sperm and the egg.

    If L refers to (a), then L couldn't "still exist" from one instant of time to the next. If L refers to (b), then again L couldn't "still exist" because objects, according to perdurantism's understanding of objects, do not persist through time. "Still exists", I say, commits one to the view that objects persist through time. I don't think there is any understanding of perdurantism according to which a numerically identical object persists from one moment to another.

  4. If "still exists" allows for an object to still exist if one of its temporal parts exists then on a 4-D view L exists just so long as one of its temporal parts exists.

    And if a 4-D object is still alive just so long as one of its temporal parts meets the conditions of biological life then that object is still alive.