Question II: What conditions are required for a just war

Most excellently, after D. Augustine book 22 against Faustus, chapter 74, and epistles 5 and 207, the following wrote on this matter: D. Thomas here; Alensis part 3, question 76, member 3; Gandavus quodlibet 15, question 16; Gabriel book 4, distinction 15, question 4; Victoria relectio on the Law of War; Castro book 2 on the just punishment of heretics, chapter 14; Covarruvias relectio on the chapter Peccatum, on the rules of law, part 2, §§ 9 and 10; Bellarmine book 3 on the Morals of the Church, chapter 14; Bannes, Cajetan, and other Thomists here; Valentia question 16, point 1; Tannerus disputation 2, question 6, dubium 3; Sylvester and other Summists, under the word Bellum. The Canonists question 23, qq. 1, 2 and 3; and D. Bonaventure in the Mirror of the Soul, chapter 1, at the end, and in the Bible of the Poor, chapter 82, where from the Scriptures he gathers wondrous examples, outstandingly proving that the integrity and prayers of the Saints contribute more to victory than arms.

FIRST, then, the Holy Doctor requires three conditions for a just war in the Mirror of the Soul, chapter 1, from D. Augustine. The first is legitimate authority. So D. Augustine at the place cited, against Faustus, chapter 74. The second is a just cause; so D. Augustine question 10 on Josue. The third is a right intention; so D. Augustine epistle 207.

AS TO the first condition, only the Prince, or the Republic, ruling absolutely, can declare offensive war. Hence Princes who are parts of some whole dominion cannot do so: so Molina disputation 100, Tannerus number 30, and the common view. For defensive war, however, all peoples and Magistrates are admitted, because anyone may repel force with force.

AS TO the second, the cause must be against an enemy unjustly and gravely injuring, as D. Augustine admonishes at the place cited. I shall set out, moreover, the specific injuries for which war may be declared, which D. Bonaventure relates in the Bible of the Poor, chapter 82.

THE FIRST is if what is owed is denied: thus the sons of Israel made war on the Amorrhites, because they denied them an unmolested passage Num. 21, and D. Augustine notes this question 43 on the Book of Numbers.

NOR indeed did Julius Caesar have a just cause, on the ground that the Romans denied access to the city, as Alphonsus a Castro thinks book 2 on the penal law, chapter 14, and Covarruvias at the place cited, § 9: for he was bound to lay down his arms at the Rubicon, since he was a subject of the Republic commanding it. Nor is just war made against the Indians on the ground that they deny free access to their provinces. So Molina disputation 105, Tannerus number 34 — provided, however, they do not resist the preaching of the faith.

THE SECOND cause is for recovering one's own possessions. Thus David fought against Isboseth, 2 Reg. 2.

THE THIRD cause is to resist invaders of the Republic. Thus the Jews often fought against the Philistines, and the Machabees against Antiochus and Demetrius.

THE FOURTH, if they render aid to unjust enemies; thus David fought against Syria of Damascus, because it brought aid to Adarezer, 2 Reg. 8.

THE FIFTH, to avenge a public injury. Thus David fought against Hannon, who had dismissed the messengers with contempt, 2 Reg. 10.

THE SIXTH, against rebellious subjects, thus David 2 Reg. 20. Hence D. Gregory infers that war against pertinacious heretics is just, book 1 of the Register, chapter 72.

THE SEVENTH, if some defend public malefactors, as D. Augustine teaches, question 10 on Josue; thus in Judges 20 the Hebrews fought against the Benjamites, their own fellow-citizens.

THE EIGHTH, on account of a violated pact; you have an example in Jotham and Josaphat, 4 Reg. 3. Therefore the sole cause of a just war is injury — to be repelled by the right of defense, or compensated by the right of commutative justice, or avenged by the right of vindicative justice — and that, when due satisfaction is not otherwise rendered. So all agree with D. Augustine book 22 against Faustus, chapter 74.

Making war, however, against infidels not baptized, Castro and others approve; but the common opinion is that it is not lawful; for no Prince has a right to this except as a member of the Church, which has no right over those not subject to it.

The Archbishop of Valencia relates in his History of America that not a few armies of Christian warfare went astray in this, who, making war upon the most wretched Indians for the sake of winning them to religion, utterly destroyed that people even to extermination: the Gospel surely does not command that nations be destroyed with such savagery, but that they be redeemed with supreme humanity and patience; it would rather be fitting to spend one's own blood on their behalf by labor and long-suffering preaching than to draw their blood off into streams; for the Apostles, Christ commands, are to be as sheep, handing them not a savage sword, but the sword of the tongue — namely, the word of God, which is more penetrating than every two-edged sword.

One who makes a just war, however, CAN call others to his aid and partnership in the war; for so the Machabees demanded the alliance of the Romans, as Tannerus notes number 52; so also everywhere among the nations, while wars are waged, we have it as established that this is done. Yet I do not refuse that where the scandal of the Christian name threatens, it is not lawful; so Molina disputation 112, Azor tomus 1, book 8, chapter 25, question 14, and Tannerus as above.

But since the necessity of the one calling them is so well known that he is recognized as compelled to do so for his own defense, not to the injury of the faith, no one will deny that scandal will arise from it for anyone. By this is clear the answer to what Valentia objects disputation 3, question 16, point 2.

One CAN also lay ambushes, and is not bound to announce the battle beforehand, as the Holy Doctor notes in the Bibliotheca, chapter 82, which he proves by the examples of Abraham Genesis 14; Josue 8 and 10; and of Gedeon, Judith 8. So Tannerus.

In doubt, however, about the just cause, the condition of the possessor is the better one, as is commonly taught, according to Valentia. Nevertheless it is reasonable also to satisfy even the adverse party, as Victoria notes number 28, Molina disputation 103, Valentia question 16, point 2, Tannerus number 41.

TAKE NOTE, moreover, that a just cause once recognized does not mean war is at once to be declared, but satisfaction must first be sought, as is had in Deuteron. 20; otherwise the undertaking will be against justice, and consequently with guilt and the obligation of restitution. So Bannes dubium 8, Tannerus numbers 32 and 51, Valentia point 2, at the end.

If, however, neither party is in legitimate possession, the thing must be divided or done by the other according to the reasons, in proportion to compensation. See Tannerus number 43.

AS TO intention, it is so necessary that if the other conditions are present but this one is lacking, it does not give rise to the necessity of restitution. So, from the common view, Cajetan teaches, Bannes here, Valentia point 2, Molina tomus 1 on justice, disputation 123, Tannerus dubium 2, number 28.

War can indeed be just on both sides per accidens, if on one side there is invincible ignorance, in which way the wars of the Amorrhites with Israel seem to have been, as Tostatus teaches on Josue 10; and then, once the truth is recognized, they are bound to withdraw and restore those things that still survive, and by which they have been made richer; as Valentia notes. But Princes must first consult the learned; otherwise, in a matter of the gravest moment, they expose themselves to the danger of guilt. So Victoria on the law of war, number 20, Valentia question 16, point 2, Molina disputation 109, Tannerus disputation 2, question 6, dubium 4, number 37.

BEYOND the conditions stated, to the substance of a just war there follows the manner of conducting it. First, indeed, in the damages to be inflicted: necessary reaction is indeed allowed, both to repair the damages inflicted and to establish peace; yet not all excesses are allowed — for instance, to kill innocents, such as women and infants, as is decreed in Exodi 23, Deuteron. 20. But if God at some time commanded that even women and infants be killed — Josue 6, in Jericho; 1 Reg. 15, against Amalech — there was a special cause by the will of the supreme Lord. So Molina, Valentia, Victoria, according to Tannerus number 66.

BEYOND children and women, however, others must be presumed innocent, as is had in the chapter Innovamus, on truce and peace, from Alexander III: Innovamus, that Priests, monks, conversi, pilgrims, merchants, rustics, those going and returning, and the animals with which they plough and carry seed to the field, be let be with fitting service. To these are added Legates or Orators, in the chapter Paternarum 24, question 3. See there.

It would nevertheless be lawful per accidens, if the citadel could not otherwise be stormed, and that storming would bring very great advantage. So Tannerus number 67, with Victoria.

It is nevertheless lawful, Valentia says, to despoil innocent enemies — namely, those who are parts of the Republic which inflicted the injury. For this can contribute both to repairing the public damage and to confirming the peace, so that the enemies, deprived of those things and weakened, may seek peace. Or if innocents of ours have been despoiled; therefore Repressalia are granted. So also Cajetan under the word bellum, Victoria on the law of war, number 41, Covarruvias on the rule Peccatum, part 2, question 4, Molina disputation 121, Tannerus number 71, Valentia at the place cited, and others.

Clerics and Churches, however, are excepted on account of their immunity, unless the enemy cannot otherwise be defeated, as Valentia notes disputation 3, question 16, point 3, with Sylvester under the word bellum, question 3, 6, and the holy Bannes article 2, last dubium.

FURTHERMORE, such a manner is to be kept that neither the Leaders nor the soldiers act against justice — the former by not paying the soldiers their stipends; the latter by pillaging; for in Luke 3 John laid it upon them: be content with your stipends.

Likewise, let them not act against fortitude by rashly exposing themselves to danger.

The manner, too, constituted by the law of nations, must also be kept: that movable things acquired be the army's; immovable things, the Prince's. See Valentia and Bellarmine at the place cited, and Tannerus number 75, who assigns movables to those who take them; immovables are designated to the Prince, the law si captivum, ff. de captivis.

TAKE NOTE, with D. Bonaventure on the passage adduced from Luke, that soldiers sin knowingly who fight in an unjust war, or are ready to fight in every war. So, from the common view, Cajetan under the word Bellum, Bannes here, question 40, article 1, dubium 6, Valentia question 16, point 2, Molina disputation as above, 103, Tannerus number 47. The reason is that to do evil, or even to expose oneself to danger, is not lawful.

Indeed, in a doubtful cause, subject soldiers, or perpetual stipendiaries, are not bound to know and examine the justice of the war, unless perhaps they have serious indications of injustice; but the rest are bound to inquire first, before they give their name to the militia. This is the common doctrine, according to Cajetan, Bannes, and others here, question 40, article 1, Victoria number 25, Molina disputations 114 and 118, Valentia point 2, Tannerus number 48. The Father, from the canon Qui culpantur, 23, question 1, after D. Augustine book 22 against Faustus, chapter 75. But Fuliensis book 3, chapter 11 adds that even foreigners can fight in the first case, if the Prince be of good repute and a Christian, of whom well is presumed.