“There are exceptions to the prohibition against killing, in cases where a just law commands it, or when public authority puts criminals to death in the exercise of its power. In such cases, it is not the man who kills, but the sword in the hands of justice.” (De Civitate Dei, I, XXI).
What a scandal! It turns out that the very Doctor of Grace admits that a judge who sentences to death or a soldier who kills in a just war does not violate the commandment “thou shalt not kill.” Come on, St. Augustine not only would not have condemned the Burgos trial, but would have sided with the legitimate authority that applies justice.
By current standards of vital coherence, he would have to be removed from the list of saints and perhaps from the study plans of moral theology. Because of course: if being against abortion but admitting the death penalty already makes you a seamless garment heretic, then St. Augustine, father and doctor of the Church, wasn’t pro-life either.
Here is the full chapter from St. Augustine on exceptions to homicide:
CHAPTER XXI
Cases of human executions that are excepted
from the crime of homicide
There are, however, some exceptions to the prohibition against killing, indicated by divine authority itself. These exceptions include both a law promulgated by God to put to death and an express order given temporarily to a person. But in this case, the one who kills is not the person who serves the authority; it is like the sword, an instrument in the hands of the one who wields it. Therefore, those men who, moved by God, have carried out wars, or those invested with public authority, and adhering to their law, that is, according to the dominion of the most just reason, have put criminals to death, did not, far from it, break the precept of “thou shalt not kill.”
The same Abraham is not only free from the crime of cruelty, but is praised with the title of pious for wanting to execute his non-criminal son, not criminally, but out of obedience39. In the case of Jephthah, the doubt arises as to whether the order should be taken as divine. Jephthah put his daughter to death because she was the one who ran out to meet him. Indeed, he had vowed to immolate to God the first thing that came out to meet him upon his victorious return from battle40. Nor is Samson excused for having buried himself with his enemies in the collapse of the house, unless the Holy Spirit, who worked miracles through him41, ordered it interiorly.
Therefore, outside of these cases, in which the order to kill is given, either generally by a just law or in a particular way by the same source of justice, God, whoever kills a man, whether himself or anyone else, contracts the crime of homicide.