§ I. On the killing of an innocent in general

472. Principles. - I. It is never licit directly to kill an innocent, whether by private authority or public, even for procuring the public good; for it is an intrinsically evil action and expressly prohibited by divine law.⁴ The innocent and just you shall not kill.⁵

II. It is licit, on account of a grave cause (that is, equal to the life of the innocent), to posit an honest action from which, beyond the intention, the death of an innocent follows, according to the principle of St. Thomas set forth at n. 461.

III. He is not guilty of homicide who, even without cause, but with diligence applied, posits an action which of itself does not bring death, from which nevertheless by accident homicide follows; because that homicide is altogether fortuitous and involuntary. But otherwise, if he posits an action which of itself brings death, or is very dangerous, and from which death often follows, even if diligence has been applied for preventing damage.¹

473. You will resolve. - 1° It is not licit to kill those lethally wounded, nor any other moribund persons whatever, lest they suffer longer; nor those who are rabid, lest they harm others, provided they can otherwise be held back from harming. The reason is that according to the known maxim evils are not to be done in order that goods may be obtained.

2° It is not licit to kill an innocent in order to satisfy a tyrant demanding his death even under penalty of a city to be overthrown, and even if he consented to his own death; the reason is that he does not have dominion over his own life. Yet more probably he could be compelled to hand himself over to the tyrant for the public good, and probably, if he were unwilling, even to be handed over. St. Alphonsus² with others.

3° It is licit in war to direct artillery against the stations of enemies, although from this even some innocents are going to suffer death; because their death follows beyond the intention.³

4° It is not licit to kill envoys or hostages, even if the enemies who sent them have not kept the faith given, and have unjustly killed hostages or envoys sent to them; because they are innocent. - Busembaum, and others commonly with St. Alphonsus.⁴

5° Physicians, midwives, and guardians of infants and the infirm sin gravely if, from grave negligence, they either do not impede, or cause, or accelerate their death. Likewise if from gravely culpable ignorance they furnish harmful things to the sick.

6° It is not licit for those voyaging, tossed at sea and escaping from shipwreck in a skiff, for the sake of lightening the skiff, which otherwise they fear is to be sunk, to throw into the sea any others than those who, last descending into the skiff, are the cause why it is to be sunk.