The fourth cause and ground for a righteous war is when there is default of keeping faith or carrying out agreements; for in such case the party who has been wronged may lawfully make war on him who, by not keeping faith, has done him injury.  This made Joran [Jehoram], king of Israel, wage war on Mesa [Mesha], king of Moab, for his having failed to keep the agreements and to pay the tribute which he had promised to pay to his suzerain, King Ahab; and that this war was just is clear, for that he was assisted therein by the holy and righteous Jehoshaphat, king of Judah, with the approval of the prophet Elisha—­who in the name of the Lord urged them on to war, and promised them a sure victory—­as is seen in II Sam. ch. 3.  These four causes and grounds, or any one of them by itself, justify war; and there are other grounds also, but these are the most certain and the most applicable to the matter in hand.

The third condition which, as we have said, must be fulfilled to make a war righteous is a right intention on the part of him who wages it; because, failing this, even when the other two conditions concur—­to wit, authority and just cause—­a faulty intention may render and does render the war unjust.  This condition is also laid down by St. Augustine (Contra Faustum), and he is quoted by Gratian (in c. Quid culpatur); and as his words are of great weight and define wherein a bad intention consists, it is well to quote them:  Quid culpatur in bello? an quid moriuntur quandoque morituri ut dominentur in pace victuri?  Hoc reprehendisse timidorum est non religiosorum.  Nocendi cupiditas, ulciscendi crudelitas, impacatus atque implacabilis animus, feritas rebellandi, libido dominandi et si quae sunt similia:  haec sunt quae in bellis jure culpantur. [21] And what must be the right intention of the prince in levying war the same Augustine declares in the book De Verbo Domini; and the passage is found in c. A pud, ubi supra:  Apud veros dei cultores et ipsa bella peccata non sunt quae non cupiditate aut crudelitate sed pacis studio geruntur ut mali coerceantur et boni subleventur. [22] Peace is the end that is to be sought in war, and so saith Aristotle (lib. 10 Ethicorum):  Bellum gerimus ut in pace degamus. [23] And Augustine says the same (Epist. ad Bonifacium):  Non quaeritur pax ut bellum exerceatur, sed bellum geritur ut pax acquiratur. [24]

But here it is to be noted that this right intention which is here required is a condition no more essential to a righteous war than to other good works, for in all these it is required, and without it no work is virtuous; and hence it is that if this right intention be wanting in the prince who levies war and in those who urge it, he would sin by wrong intention, but if the other two conditions be fulfilled, he, as Soto says, will not be held to make amends for the injuries that may be done in the war.  So, too, if a judge orders a robber to be hanged, granted that ex odio suspendat, [25] he will not be held to restitution, if on the testimony adduced the man deserved hanging.