I desire mercy, not sacrifice (Hos 6:6; Mt 9:13).
‘Just war’ according to the Scholastics
Formal ‘just war’ doctrine in Western Christianity is thought to have commenced with Saint Augustine. This was based on the following passage written by the Apostle Paul in his Letter to the Romans:
For the one in authority is God’s servant for your good. But if you do wrong, be afraid, for rulers do not bear the sword for no reason. They are God’s servants, agents of wrath to bring punishment on the wrongdoer (13:4).
Augustine, in his Contra Faustum Manichaeum, argued that Christians did not need to feel ashamed of protecting peace and punishing wickedness when mandated to do so by a government. However, he asserted that this argument was personal and philosophical: “What is here required is not a bodily action, but an inward disposition.” In the meantime, in his work The City of God, Augustine elaborated:
They who have waged war in obedience to the divine command, or in conformity with His laws, have represented in their persons the public justice or the wisdom of government, and in this capacity have put to death wicked men; such persons have by no means violated the commandment ‘Thou shalt not kill’ . . . the wise man will wage Just Wars. As if he would not all the rather lament the necessity of just wars, if he remembers that he is a man; for if they were not just he would not wage them, and would therefore be delivered from all wars.
Saint Thomas Aquinas
In the Summa Theologica written 900 years later, Saint Thomas Aquinas revised Augustine’s stance by formulating three criteria that were all required to be met in order for a war to be considered ‘just.’ These criteria were that:
- The war had to be declared and waged by a legitimate authority (e.g., the state);
- The cause for war had to be both just and good (e.g., to restore something that had been lost), rather than carried out for self-gain or power; and
- The right intent for the war needed to underlie the decision to go to war.
Specifically, according to Thomas:
In order for a war to be just, three things are necessary. First, the authority of the sovereign by whose command the war is to be waged. For it is not the business of a private individual to declare war, because he can seek for redress of his rights from the tribunal of his superior. Moreover it is not the business of a private individual to summon together the people, which has to be done in wartime. And as the care of the commonweal is committed to those who are in authority, it is their business to watch over the commonweal of the city, kingdom or province subject to them. And just as it is lawful for them to have recourse to the sword in defending that commonweal against internal disturbances, when they punish evil-doers, according to the words of the Apostle (Romans 13:4): “He beareth not the sword in vain: for he is God’s minister, an avenger to execute wrath upon him that doth evil;” so too, it is their business to have recourse to the sword of war in defending the commonweal against external enemies. Hence it is said to those who are in authority (Ps 81:4): “Rescue the poor: and deliver the needy out of the hand of the sinner;” and for this reason Augustine says (Contra Faust. xxii, 75): “The natural order conducive to peace among mortals demands that the power to declare and counsel war should be in the hands of those who hold the supreme authority.”
Secondly, a just cause is required, namely that those who are attacked, should be attacked because they deserve it on account of some fault. Wherefore Augustine says (QQ. in Hept., qu. x, super Jos.): “A just war is wont to be described as one that avenges wrongs, when a nation or state has to be punished, for refusing to make amends for the wrongs inflicted by its subjects, or to restore what it has seized unjustly.”
Thirdly, it is necessary that the belligerents should have a rightful intention so that they intend the advancement of good or the avoidance of evil. Hence Augustine says (Can. Apud. Caus. xxiii, qu. 1): “True religion looks upon as peaceful those wars that are waged not for motives of aggrandizement or cruelty, but with the object of securing peace, of punishing evil-doers, and of uplifting the good.” For it may happen that the war is declared by the legitimate authority and for a just cause, and yet be rendered unlawful through a wicked intention. Hence Augustine says (Contra Faust. xxii, 74): “The passion for inflicting harm, the cruel thirst for vengeance, an unpacific and relentless spirit, the fever of revolt, the lust of power and such like things, all these are rightly condemned in war” (Question 40: War).
Thus, the three criteria set forth by Thomas were elaborated into the following seven sub-criteria that all needed to be met for a ‘just war’ to be in effect:
- It had to be carried out as a last resort;
- This could only be done by a legitimate authority;
- The war to be carried out for a truly just cause (i.e., not just any cause);
- There had to be a significant probability of success as a result of the proposed war;
- The intent underlying the decision to go to war had to be ‘right’ (i.e., not in revenge for perceived or actual wrongs);
- The degree of force used could never be more than what was needed to attain success (i.e., proportionality); and
- Civilians could never be the primary target of the war.