In response to the previous post on Islam, a question was raised to the effect of “Can a just war exist?” Here is a summary answer to this question from the lens of Christianity.
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.