Proponents of the Doctrine of Double Effect draw a distinction between two sorts of cases: (1) you intend to achieve a particular result R through your action (i.e., this result is the purpose of your action) and (2) you intend to achieve a different result T through your action but foresee that your action will have an additional (though non-intended) result R. What’s crucial, according to this doctrine, is the object of one’s intentions. In the case of abortion, the intended purpose of the procedure is to terminate a pregnancy. In most cases of ectopic pregnancy, the purpose of the surgery is to save the life of the pregnant woman, and a foreseeable, though not intended, result of the procedure is the termination of a pregnancy. (How can you tell whether the result is intended, rather than merely foreseen? See whether you would still perform the action if you were to learn that the result would not occur.)

I am not a fan of the Doctrine of Double Effect. It seems to me to depend on a distinction that makes no moral difference. To see this, let’s imagine that I have a very important appointment across town and that I’m currently stuck in traffic. The only way that I can get to my appointment on time is by driving on the sidewalk and running over a lot of people. Of course, I don’t intend to kill anyone; killing is not the purpose of my action. If I could get across town without killing anyone, I would. Nonetheless, I can easily foresee that driving on the sidewalk will put many people in harm’s way. On my view, the fact that I don’t intend to kill the pedestrians whose death I could easily foresee makes no moral difference whatsoever.

Now, of course, proponents of the Doctrine of Double Effect also would not endorse my running over pedestrians in the circumstances that I imagine. They would say that in order for my action to be permissible, the harm that I’m trying to avoid must be “proportionately” as significant as the harm that I can foresee that I will cause. Since in the case of an ectopic pregnancy the life of the mother and the life of the fetus are equally significant, surgery that terminates the pregnancy is permissible.

So, let’s change the case of our impatient driver just a bit. Let’s say that I’m a very courageous and skilled firefighter called to a burning apartment building across town. Let’s also stipulate that my town is very poor, and though populous, very remote. I am the only firefighter within hundreds of miles. I believe that it is important to save the lives of the people who are trapped in the burning building, but the only way that I can get to them in time is by driving on the sidewalk (due to budget cuts, my broken siren and horn still have not been repaired, and due to an injury suffered in a previous daring rescue, I am mute). According to the Doctrine of Double Effect, so long as I don’t intend to kill the pedestrians (even if I can foresee their death) and so long as I intend to save the lives of the many trapped residents of the burning building, my sidewalk escapades would be morally permissible. While I myself think that it is actually quite difficult to explain why I should not drive on the sidewalk in these circumstances, I trust that most Catholics will agree with me that I should not.

Of course, the case of an ectopic pregnancy is importantly different from this last case. If a physician doesn’t save the life of the mother, both the fetus and the mother will die. But isn’t this the fact that should be most morally relevant to a person who believes that human life is sacred from the moment of conception? The fetus will die no matter what; the mother’s life can be saved. If human life is sacred, the mother’s life should be saved. There’s no need for an appeal to the Doctrine of Double Effect.