Therapeutic abortion, as has been said, is never permissible, under any circumstances, if the child is not viable. In certain conditions, say, when a uterine tumor clearly threatens the life of the pregnant woman, or if in extrauterine gestation there is a rupture of the tube, an operation may be permissible, or even obligatory, which has for its direct end the removal of the tumor or the stopping of the hemorrhage. If such a removal or ligation, under these conditions, indirectly causes the abortion of the inviable fetus, or its death from a lack of blood, these indirect effects may be reluctantly permitted. They are cases of an equally immediate double effect, one good and one evil, where all the requirements are fulfilled. A _direct_ abortion of an inviable fetus, however, is never licit even to save the mother's life, and in abortion the killing is _direct_ because it is used as a means to an end. In a ruptured ectopic gestation the primary effect of the physical operation is to ligate the torn arteries to save the woman's life here and now; the secondary effect is the permitted death of the fetus from the shutting off of the blood supply. In the abortion of a premature fetus the primary effect of the operation is to separate the placenta from the uterus, to cut off the child's blood supply, and as a direct consequence of this act, which is essentially evil, the woman's life is saved. The original act in this abortion is evil, and evil may not be done even if good follows. Even in self-defence against an unjust aggressor one may not kill a man to save his own life--he tries to save his own life and reluctantly permits the death of the aggressor. In a killing in self-defence there are two distinct effects; in abortion there is only one effect, and the killing is a means to this one effect. That you may kill an irresponsible insane man who is attacking your life, or the life of one entrusted to your care, is no reason that you may attack a fetus in the womb. There is no parity. The insane man is a materially unjust aggressor; the fetus is not an aggressor at all. The mother placed it where it is; and if any one is an aggressor, she is. In the abortion you directly kill the fetus and indirectly save the woman's life, and this indirection uses the death of the fetus as a means to the end of saving the woman's life. In killing the insane aggressor you directly save the life of yourself or your ward, and reluctantly permit the death of the aggressor. The proofs of the essential immorality of direct homicide have already been established in the general chapter on Homicide.