Summa contra Gentiles3.146 Chapter CXLVI. That it is lawful for judges to inflict punishments

Whereas some belittle the punishments inflicted by God, forasmuch as, being attached to sensible things, they care only for outward appearances: divine providence has ordered that on earth there be men who, by inflicting sensible and present punishments, compel certain people to do right. Now, it is clear that they sin not in punishing the wicked. For no man sins through doing right: and it is right for the wicked to be punished, since by punishment sin is righted, as we have shown above. Therefore judges do not sin by punishing the wicked.

Again. Men who are placed over others on earth, are executors, as it were, of divine providence: because God, by the ordinance of His providence, accomplishes lower things through higher things, as we have proved. Now, no man sins through carrying out the order of divine providence. And divine providence has ordained that the just be rewarded, and the wicked punished, as we have shown. Therefore men who are placed over others do not sin, by rewarding the good and punishing the wicked.

Besides. The good needs not the evil, but conversely. Therefore that which is necessary in order to maintain the good, cannot be evil in itself. Now, it is necessary for punishment to be inflicted on evil-doers, for the maintenance of peace among men. Therefore punishment of evil-doers is not an evil in itself.

Also. The good of the community surpasses a particular good of the individual. Therefore the particular good must give way, that the common good may be maintained. Now, the life of a few pestilential individuals is a hindrance to the common good, which is the harmony of the human community. Therefore such men should be cut off by death from the society of their fellows.

Besides. As the physician in his operation aims at health consisting in the ordered harmony of the humours, so the governor of a state, in his operation, aims at peace, which is the ordered harmony of the citizens. Now, the surgeon rightly and usefully cuts off the unhealthy member, if it threatens the health of the body. Justly, therefore, and rightly the governor of the state slays pestilential subjects, lest the peace of the state be disturbed.

Hence the Apostle says (1 Cor. v. 6): Know you not that a little leaven corrupteth the whole lump? And a little further on he adds (verse 13): Put away the evil one from among yourselves. Again speaking of earthly authority he says (Rom. xiii. 4) that he heareth not the sword in vain: for he is God’s minister: an avenger to execute wrath upon him that doeth evil. Again it is said (1 Pet. ii. 13, 14): Be ye subject... to every human creature for God’s sake: whether it be to the king as excelling: or to governors as sent by him for the punishment of evil doers, and for the praise of the good. Hereby we refute the error of those who say that capital punishment is unlawful. They base their error on the words of Exod. xx. 13, Thou shalt not kill, which are quoted Matth. v. 21.—They also quote the saying of our Lord (Matth. xiii. 30) in reply to the servants who wished to gather the cockle from the midst of the wheat: Suffer both to grow until the harvest: for the cockle signifies the children of the wicked one, and the harvest is the end of the world, as stated in the same passage. Therefore the wicked should not be cut off from the midst of the good, by being condemned to death.

They also point out that as long as he is on earth man may be converted to better ways. Therefore he should not be put away from the world, but should be kept there that he may repent.

But these arguments are of no account. For the same law that says, Thou shalt not kill, afterwards adds: Wizards thou shalt not suffer to live. Hence we are to understand that the prohibition is against the unjust slaying of a man. This is also evident from our Lord’s words in Matth. v.

For after saying, You have heard that it was said to them of old: Thou shalt not kill, He added:x But I say to you that whosoever is angry with his brother, etc. Whereby He gives us to understand that it is forbidden to kill through anger, but not through zeal for righteousness.—How we ought to take our Lord’s words, Suffer both to grow until the harvest, is clear from what follows: Lest perhaps gathering up the cockle, you root up the wheat also together with it. Hence, it is forbidden to slay the wicked, when this cannot be done without danger to the good. And this is often the case, when the wicked are not yet discernible from the good by notorious sins; or when it is to be feared lest the wicked draw many good men after them. The fact that the wicked, while alive, are able to amend, does not prevent their being justly slain: because the peril that threatens through their remaining alive, is greater and more certain than the good to be expected from their amendment. Moreover, in the very hour of death they are able to repent and be converted to God. And if they be so obstinate, that even in the hour of death their heart abandons not its wickedness, it may be reckoned with sufficient probability that they will never recover from their evil ways.