[104] "In a case of necessity, it is licit to do a laparotomy for the removal of an ectopic gestation sac from the maternal pelvis, provided the life of both fetus and mother be carefully safeguarded."
[105] "Negative, juxta decretum 4 Maii, 1898, vi cujus, foetus et matris vitae, quantum fieri potest serio et opportune providendum est: quod vero tempus, juxta idem decretum, orator meminerit, nullam partus accelerationem licitam esse, nisi perficiatur tempore et modis, quibus ex ordinarie contingentibus, matris ac foetus vitae consulatur."
If the fetus is removed and so killed to avert a threatened danger to the maternal life, but not an actually operative destruction of her life, this removal or homicide is an evil means used to avert the danger. There is no question of a double effect, that is, of two effects, one good and the other evil, coming with equal directness from the cause, which is the removal or killing of the fetus; but of a good effect, the averting of the danger to the mother, issuing from an evil cause, the removal and death of the fetus. A good effect does not justify the use of evil means; it is not permitted morally _directly_ to kill the fetus, as in this case, to save the mother from a _threatened_ grave danger.
The case is not like that of the woman who has an operable cervical cancer while she is bearing an inviable fetus. If the cancerous uterus is not removed the woman will surely die; if it is removed she has a reasonable chance of cure; but if the inviable ectopic fetus is not removed it is by no means certain that the woman will die. In the cancer the uterus is directly removed, the fetus is indirectly killed; in the ectopic case the fetus is directly killed, and the danger to the woman's life is removed as a direct effect of the killing.
Again, the killing of the inviable ectopic fetus cannot be justified by maintaining that the fetus is an unjust aggressor against the life of the mother. An aggressor against life may be such formally or materially. A formally unjust aggressor consciously and voluntarily attacks the life of the victim unjustly. This perversion, or evil, in the aggressor's consciously actuated will sets his own right to life in juridic inferiority to that of the victim's right to life, and the victim may defend his own life, even unto the indirect death of the aggressor in necessity.