Article II. On the Killing of an Unjust Aggressor

I say. It is licit for each person to defend his own life even with the killing of an unjust aggressor, provided nevertheless that the moderation of inculpable defense is preserved. The reason is taken both from canon law, chap. Si vero 8, de sent. excomm., where it is said: "All laws and all rights permit force to be repelled by force"; and from natural law. For since each person has the right to preserve his own life, he must also have the right of employing the means which are necessary for this end and not otherwise illicit. But to kill an unjust aggressor is sometimes the sole means of saving one's own life, nor through this are any certain rights of anyone violated; since the aggressor, by freely and unjustly bringing into danger the life of another, cannot retain the right to his own life against the certain right of an innocent person. Therefore.

Yet I added that the moderation of inculpable defense is to be preserved, or that nothing ought to be done against the life of the aggressor unless it is absolutely necessary for protecting one's own life, because what necessity does not excuse is contrary to justice. - Cf. St. Thomas, 2-2, q. 64, art. 7. - St. Alphonsus, n. 380.

Question 1. Is it licit to kill a drunken or insane aggressor?

Response. Affirmatively, more probably, unless it is clear to you that he is in the state of mortal sin. The reason is that although a drunken or insane person is not formally your unjust aggressor, nevertheless he is materially unjust, nor is your right to life lost through his drunkenness or insanity. But if you know certainly - which surely will be very rare - that he is in the state of mortal sin, from which after frenzy or drunkenness he will be able to rise again, while on the contrary you morally believe that you are in the state of grace, charity requires that you prefer his eternal salvation to your temporal life. Yet nothing prevents, even in that hypothesis, you from striking or wounding him in such a way that, his life being safe, he becomes unable to do harm. Cf. Lugo, de just. et jur., disp. 10, n. 143.

Question 2. Is it licit to defend goods of fortune of great moment with the killing of the thief, if otherwise they cannot be retained?

Response. Affirmatively, more probably, and the reason is that each person has the right of preserving goods of great moment, and by that very fact of employing the means absolutely necessary for this. Besides, the precept of charity does not oblige one to prefer the goods of a neighbor, though of a higher order, except when the neighbor is in extreme necessity, but not when he spontaneously exposes himself to the danger of death and injures the rights of another. By this same reason it is concluded that an unjust aggressor can be killed for the defense of members. - Cf. St. Alphonsus, n. 383 and following.

Question 3. Is it licit for a woman to kill an assailant of chastity?

Response. Affirmatively, because chastity is a good more excellent than riches; and accordingly if it is licit to kill an unjust aggressor of goods of fortune, this will be licit a fortiori for preserving chastity. But a girl cannot kill an aggressor against her honor after violation, because this would be to take vengeance; nevertheless she can strike him and treat him most harshly, especially because, unless in such a way she shows her constancy and displeasure, the wicked man will not easily depart, or will easily be able to return to soliciting. - Cf. St. Alphonsus, n. 386.

Question 4. Is it licit to kill an unjust aggressor against honor?

Response. Negatively, altogether, if the injury has already been inflicted, in whatever way it has been inflicted, whether by words or by deeds; because this would not be to defend oneself but to take vengeance, which is licit for no one. It is also clear from the second part of prop. 30 proscribed by Innocent XI, which has itself thus: "It is lawful for an honorable man to kill an assailant who attempts to inflict calumny, if otherwise this calumny cannot be avoided: the same also must be said if someone strikes with a slap or with a stick, and after the slap has been struck or the blow of the stick flees." - One must also respond negatively if it concerns preventing or repelling an injury of honor inflicted by words only, both because the injury can then and usually does get repelled by other means, and accordingly killing is not necessary, and because otherwise an entrance would lie open to innumerable slaughters. - Besides, prop. 17 condemned by Alexander VII bears on this point, which sounds thus: "It is licit for a Religious or Cleric to kill a calumniator threatening to spread grave crimes about him or about his Religion, when another mode of defending does not suffice, as it does not seem to suffice if the calumniator is prepared publicly and before most grave men to impute the aforesaid things either to the Religious himself or to his Religion, unless he is killed." - I said by words only, for if an aggressor against honor attempts to pull the beard, soil the clothes, or do something similar, it will certainly be licit, with the moderation of inculpable defense being preserved, to repel the injury, and if indeed the obstinate aggressor, having been repelled, employs force and seizes weapons, it will surely be licit to oppose weapons to weapons. - Cf. St. Alphonsus, nn. 381 and 391. - Viva, on the cited propositions. - Lacroix, lib. 3, p. 1, n. 803. - Baller., note (b) and (c), p. 378.

Question 5. Is it also licit to kill an unjust aggressor against one's neighbor?

Response. Affirmatively, in every case in which it is licit to defend one's own life or other goods of great moment: indeed it is not only licit, but it ought also to be done by reason of charity. Yet rarely does a private person seem to be bound to this, on account of the great inconveniences which such killing ordinarily brings with it, excluding the case in which the person attacked is very necessary to society, or joined very nearly to you by blood. Cf. St. Alphonsus, nn. 389 and 390. Baller., note (c), p. 377.