§ 1. It is an impious saying that a commander in war cannot be just because so many things occur which persuade or compel him to be unjust. For once war has been declared, vices are let loose among subjects and soldiers. If you are a diligent exactor of military discipline, if you prohibit plunder from peaceful territory and injury, the soldiers’ pay must also be paid, and without delay. If you indulge them a little, if money is lacking, injuries will be inflicted upon the subjects—not slight ones, but as great as military license is accustomed to conceive. The innocence of the commander is therefore placed in this danger. Nevertheless, if he has undertaken a necessary war, since he cannot guarantee its outcome, all the losses rebound upon its author. If he cannot restrain the soldier or sufficiently protect the subjects, his conscience will console him if he has omitted nothing whereby all things might be rightly administered.
§ 2. I demand not only justice in war, but also, amid the greatest dangers, the piety of the soldiers and commander. For since great dangers of death hang over them, those who do not prepare themselves for them sin mortally. Thus a war of Christians ought to be such that the camps are not unlike churches; for camps are assemblies of men going to death. Hence both a prosperous end to the war and victory in individual engagements must be sought from God. Since in war very many things occur contrary to expectation, not only forces but also the will of the Deity must be considered. Nowhere less than in war does the outcome answer to expectation: iron and bodies are on both sides; unseen leaden balls fly, and a man is deservedly laughed at if he appears like one trying to dodge them. War is the contest of men in sound health. Therefore aid must be sought from God and God must be kept before one’s eyes: for true courage rests upon God.
§ 3. Wars supported by prayers have ended most prosperously. In Exodus 17 Moses prays while the Israelites fight, and the Amalekites are conquered: “And Joshua did as Moses had spoken, and fought against Amalek; but Moses, Aaron, and Hur went up to the top of the hill. And when Moses raised his hands, Israel prevailed; but if he lowered them a little, Amalek prevailed. And the hands of Moses were heavy. Therefore, taking a stone, they placed it beneath him, and he sat upon it; but Aaron and Hur supported his hands on either side. And it came about that his hands did not grow weary until the setting of the sun. And Joshua put Amalek and his people to flight by the edge of the sword.” And in Numbers 21:2: “But Israel, binding himself to the Lord by a vow, said: ‘If you deliver this people into my hand, I will destroy its cities.’ And the Lord heard the prayers of Israel and delivered up the Canaanite, whom he killed after overthrowing his cities; and he called the name of that place Hormah—that is, anathema.”
The Lord also appeared to Joshua and strengthened him; even the sun obeyed him, so that it did not set until he had pursued the enemies of the Lord. God assisted David, Jehoshaphat, Hezekiah, and the other pious kings, especially the Maccabees, who gained very many victories against forces of veterans. But it must be observed that they were readily heard when they began war after consulting God. For that each man should stir up wars according to his own desire and endeavor to draw God according to his own judgment has more impudence than piety. For if you did not deign to seek counsel from God, how do you seek aid? God is present as moderator at the beginnings, courses, and ends of wars. Among so many battles waged in such various places, wherever aid was piously and faithfully sought from God, you will scarcely find one in which military prayers were not heard.
We Christians have had few commanders in war equal to Narses. In many battles he defeated the most powerful enemies; he always emerged victor through the power of God, not through confidence in his army. Since he was generous to the poor and merciful to suppliants, he worshiped God with such piety that he spent entire nights in basilicas. Thus everyone believed what was also true: that he obtained victory more by prayers than by arms. Prayers are certainly stronger against enemies than iron; and although a Roman historian calls it folly to believe that war can be brought to an end by sitting or by vows, Narses nevertheless conquered Totila after he had passed a sleepless night in continuous prayer and had left pools that were almost witnesses to his tears.
Thus he defeated Totila, encountered Theudebert the Frank, and crushed his commanders Buccelin and Amingus. He hanged Suitald, king of the Bretons, from a high beam in peacetime as a traitor. He performed deeds as great as few of the ancients: for he experienced the presence of Christ in every danger and deservedly expected the protection of him whose religion he cultivated. God himself is accustomed to preside over the just cause. “Are you one of ours, or of our adversaries?” Joshua, commander of the Israelites, asked; and by his answer the angel showed to whom victory belonged: “By no means; but I am prince of the army of the Lord, and now I have come.” If this prince is present, for him there is no difference whether he gives aid through few or through many, as Asa, king of Judah, piously and faithfully says. God, moreover, even threatens Amaziah: “But if you think that wars consist in the strength of an army, God will cause you to be conquered by the enemies; for it belongs to God to assist and to turn to flight.”
Therefore battle is waged against enemies from heaven: the stars, remaining in their order and course, fight against Sisera when victory is sought from God with humility in a just cause—a victory which is more often obtained by the faith of commanders and holy men than by the strength of soldiers. Thus Theodosius defeated Maximus and Eugenius when the wind turned their missiles back upon the enemy. It is wonderful and beyond every custom of war that, during the reign of Honorius, one or two hundred thousand men fell with Radagaisus while not even one man in the camps of Honorius was wounded. Mascezel routed his brother Gildo with five thousand men after seventy or eighty thousand had been slain, for Gildo scarcely endured the clash. During the reign of the younger Theodosius, one hundred thousand Persians perished in the Euphrates through panic. Three thousand Burgundians, after being baptized and praying to God, struck down ten thousand Huns.
The Christians besieged at Antioch destroyed one hundred thousand Saracens. The Spaniards too, though few, conquered immense kingdoms in both Indies. The examples are ready to hand.
I make this admonition as well: even the Gentiles especially entreated their gods in battles. Hence the Romans did not march out except after taking the auspices and performing sacred rites. Constantine, founder of the Eastern Empire, and Charles, founder of the German Empire, conquered the enemy chiefly by prayers. Constantine passed nights in prayer; Charles ordered public supplications for three days.