Those against whom I am writing take it amiss that I esteem Cato less than the saintly man Job, who preferred to endure incredible afflictions in his body rather than to rid himself of them by suicide. I also honor other holy men of whom it is related, on the authority of our reliable books, that they submitted to captivity and the tyranny of their enemies rather than to take their own lives. But, even on the authority of my opponents’ books, I should place Regulus above M. Cato. After all, Cato never defeated Caesar; when he himself was defeated, he disdained to submit to the victor, and to avoid subjection he decided to do away with himself.
Regulus, on the other hand, had once routed the Carthaginians, and, as commander of the Roman forces, gained, not a victory over his fellow citizens to be lamented, but a victory over the enemy to be celebrated by the Roman republic. But, when he later fell into their hands, he preferred captivity to suicide. As a result, Regulus preserved with honor both his power of endurance under the Carthaginians and the admiration of his constancy in the hearts of the Romans, and thus left his conquered body with the enemy and his indomitable spirit with his fellow citizens. Nor was his refusal to do away with himself prompted by his inordinate love of life. Of this he gave ample proof when, in virtue of the oath he had sworn to his enemies, he returned to them without the slightest hesitation, after he had done more harm by his words in the Senate than he had done by arms in battle.
Hence, his contempt for this life, shown by preferring to let cruel enemies end his life by torture rather than to take it by his own hand, is beyond doubt to be taken as his reasoned conviction that suicide is a great crime. In the galaxy of their most celebrated men distinguished for virtue, the Romans can proudly point to no greater man than Regulus—a man whom no prosperity corrupted, for he remained poor despite his great victory, and whom no adversity broke, for he returned to incredible torments with resolute and undaunted spirit.
These eminently brave and notable men, who had only an earthly fatherland to protect and who, indeed, worshiped false gods—but with sincerity, scrupulously observing the oaths sworn to them—had the right by the laws of war to put their conquered foes to the sword. Nevertheless, they refused to put themselves to the sword in the event of defeat. Though they had no fear of death, they preferred to submit to arrogant victors rather than take their own life. If those men did so, with how much greater reason should Christians, who adore the true God and have their hopes fixed on a heavenly fatherland, recoil from that crime, even though Divine Providence should bring them under the enemy’s heel for a time—to test their virtue or to reform their ways.
The Most High never abandons His followers in their distress. He deigned to come down to earth in humble estate for their sake, especially as He knew that they are bound by no law of war or the orders of any military power to put a vanquished foe to the sword. What error, therefore, so insidious has ever stolen into men’s mind as to imagine that a man may take his life because an enemy has wronged him or might wrong him. A Christian may not even put to death the enemy himself who has done, or intends to do, him mischief.
Augustine of Hippo, The City of God, Books I–VII