I think that this is a very, very interesting topic. I have thought about it before myself. Every point of reason I can think of seems to suggest that taking physical action against an abortionist to prevent the murder of an unborn child is not intrinsically immoral. I can’t get myself to come out and say I agree with that, however, because something about it seems wrong. Note that I do not refer to killing here, but only physical force. I think there is a big difference, because one can prevent an abortion without killing the abortionist but merely by knocking him unconscious, for example. In any case, I don’t know the answer, but I don’t think it’s nearly so easy to shrug off the idea as some would suggest.
For example, having read the thread, the objection that seems to be holding the fort, so to speak, right now is that killing an abortionist would only put off the abortion, not prevent it. This argument is simply fallacious.
On a battlefield, shooting an enemy soldier who is about to slay a companion may only put off his ultimate death, yet this is not immoral. If the mob has it out for a person and you walk in on the hitman about to pull the trigger, shooting him would not be immoral, even though the reality is you are just putting off the asassination by some period of time. In fact, we are all ultimately going to die at some point, so one might even find a good way to stretch the argument to say that its never alright to use force to defend the innocent because it only puts of the person’s death anyways.
Now those are all examples, but the real problem is that this argument attempts to judge the morality of an act on something that happens far in the future, as opposed to the act itself. An act itself is either moral or immoral regardless of indirect future results.
Now, I do think it would be immoral to actually
kill the abortionist. If we take into account the Church’s teaching on the death penalty, we will begin to see why. The Church declares that the death penalty is moral, but only when it is the only way to protect others from an agressor. Thus, if a some super villian with terrible powers that could not be imprisoned were running around, then the death penalty may be warranted.
Now killing an abortionist won’t protect the child from the agressor, because as has been pointed out, another abortionist can be found, and thus I think the objection stands on this ground. However, as I said, even putting off an abortion by a few days may justify a lesser act of force, just as an agressor can have a lesser punishment - incarciration - put upon him if it will protect people even for a time, such as until the next agressor tries to commit a crime against them.
From reading Aquinas, I believe his answer would also be that one cannot intend to kill an abortionist to prevent an abortion, but one can use physical force that is not intended to kill the abortionist in order to prevent it:
I answer that, Nothing hinders one act from having two effects, only one of which is intended, while the other is beside the intention. Now moral acts take their species according to what is intended, and not according to what is beside the intention, since this is accidental as explained above (43, 3; I-II, 12, 1). Accordingly the act of self-defense may have two effects, one is the saving of one’s life, the other is the slaying of the aggressor. Therefore this act, since one’s intention is to save one’s own life, is not unlawful, seeing that it is natural to everything to keep itself in “being,” as far as possible. And yet, though proceeding from a good intention, an act may be rendered unlawful, if it be out of proportion to the end. Wherefore if a man, in self-defense, uses more than necessary violence, it will be unlawful: whereas if he repel force with moderation his defense will be lawful, because according to the jurists [Cap. Significasti, De Homicid. volunt. vel casual.], “it is lawful to repel force by force, provided one does not exceed the limits of a blameless defense.” Nor is it necessary for salvation that a man omit the act of moderate self-defense in order to avoid killing the other man, since one is bound to take more care of one’s own life than of another’s. But as it is unlawful to take a man’s life, except for the public authority acting for the common good, as stated above (3), it is not lawful for a man to intend killing a man in self-defense, except for such as have public authority, who while intending to kill a man in self-defense, refer this to the public good, as in the case of a soldier fighting against the foe, and in the minister of the judge struggling with robbers, although even these sin if they be moved by private animosity.
