So it is hard to see how removing the tube “accidentally” removes the child.
It’s not supposed to make sense, it’s legal fiction.
Catholic ethics is not situational or consequntialist – it’s deontological. Further, it includes an absolute prohibition on feticide, with a very severe sanction (excommunication). Therefore, as far as the pure cannon law is concerned, there is absolutely no way a doctor can treat an ectopic pregnancy. Ectopic pregnancy is treated by the removal of the embryo, which, by definition, constitutes an abortion – an this is excommunicable in any and all circumstances. Further, if you were to take a gun and shot a woman with ectopic pregnancy in the head, then you are in less trouble then if you removed ectopic pregancy – because murder is nor an excommunicable offense, while abortion is.
The only way that a Catholic doctor can treat an ectopic pregnancy is to resort to a legal fiction based on the double effect principle. Justifying a forbidden act (in this case, abortion) under the double effect requires you to fulfill 4 conditions:
(1) The nature-of-the-act condition. The action must be either morally good or indifferent.
(2) The means-end condition. The bad effect must not be the means by which one achieves the good effect.
(3) The right-intention condition. The intention must be the achieving of only the good effect, with the bad effect being only an unintended side effect.
(4) The proportionality condition. The good effect must be at least equivalent in importance to the bad effect.
(4) is obvious.
(3) essentially means that you are allowed to hand-wave all the bad effects as long as you claim that you wanted to achieve only the good effect, and there was just no way you could have avoided the bad effect.
Regarding (1) the problem is that Catholicism ethics assigns moral value to the action
itself, irrespectively of the circumstances. Helping the poor is good, even if you are helping them with stolen money. Abortion is evil, even if you are trying to save the woman. This criterion is also the first reason why removing the fetus from the tube is illicit – it is abortion by definition, therefore illicit, end of story. But removal of the tube is morally neutral – it does not kill anyone.
But, aren’t we removing the tube because there is a child inside? Well… no. We’re removing the tube,
because it will rupture and we’re keeping quiet on the reason
why it will rupture. This is how we satisty condition (2) of the double effect. If we remove the tube, then it will not rupture, simply because it is no longer there! Now, the removal of the tube will kill the embryo – this is true. But (2) does not demand that the bad effect does not happen – it demands, that the bad effect does not happen because of the good effect. The embryo dies
because the tube was removed, not
because the tube will not rapture. What (2) demands is that you must demonstrate that there is no causal relationship between the
effects.
A simple way to visualize it is by flipping dominos. Say you have one white domino (good effect), and one black domino (bad effect). If you flip the white domino, so that it falls on the black one, then the flipping of the black one proceeds from flipping of the white one – this does not satisfy the double effect. On the other hand, if you take some green dominos and place them so they will
independenly flip both the white and black after you initiate the process – then this falls under the double effect.
Now, if you go all the way back and read the Gospel, then you will realize that this kind of ethical hair-splitting is exactly what Jesus was criticising Pharisees for.