Augustine, Aquinas, and War

To stress that war is not just a reality we study in history but one that continues to haunt us in the present is not difficult. We often see images of the suffering wars cause and the intense debates they provoke. It’s easy to get overwhelmed by the stream of data, of fact upon fact, and feel powerless to do anything about a surge of information in which we are submerged. It may stir up feelings of anger, sadness, guilt, or compassion. Or the constant exposure to it may leave us numb and apathetic. We may wonder, as persons or as communities, how to respond appropriately when we think or express ourselves around this highly sensitive topic. Part of the historian’s, and in general, of the humanities scholar’s task is to ask what can be said responsibly about war. 

From the study of highly specific cases of conflict, both past and present, we can establish the facts of what happened as best we can: what were the causes and conditions of each conflict as well as its impact on societies at the time and in the legacy it left (or spoiled) for humanity in the periods that followed? But when it comes to its ends, aside from the violence and destruction it inevitably brings, we should ask ourselves whether there are or could be any universal criteria for when war is justifiable and when it is not.

From the perspective of Orthodox Christianity, the starting point would naturally be the light by which we see and test all things, holding fast to what is good, that is, Jesus Christ, the very God who sanctifies us wholly. (1 Thessalonians 5:21-23) 

Now, the Christian who wishes to justify war will encounter a stumbling block right out the gate when he thinks upon the words of Christ in the Beatitudes: Are we not exhorted to love our enemies and pray for those who persecute us? (Matthew 5:44) Has not He who gives us peace not as the world gives (John 14:27) told us how worldly justice is “an eye for an eye”?

Yet Scripture also says, “Turn the other cheek” (Matthew 5:39) and “They that take the sword shall perish with the sword.” (Matthew 26:52)

The Apostle gives us the Pauline principle: Shall we do evil that good may come? (Romans 3:8) Nay, but we return always good for evil. These words are a perfect gift from the Father of lights (James 1:17), that we might turn our hearts from the corrupt inversion of justice proposed by cynical “realists” like Machiavelli who propose to bring about a stable and benevolent state of affairs through cruel means.

Their “virtue,” which is just the power to do the possible, is not ours, which tends to perfection in the unity of the Holy Spirit. 

So those who adhere to strict pacifism, particularly of the kind that embraces nonviolent resistance to injustice rather than a purely passive non-resistance, would have their hearts in the right place, at least from this perspective.

Yet in a fallen world where our families and communities are threatened by the vicious, we have to read verses of scripture not in isolation but in line with tradition, and to understand our duties of faith in a holistic way.

“Give justice to the weak and the orphan; maintain the right of the lowly and destitute. Rescue the weak and the needy; deliver them from the hand of the wicked.” (Psalm 82:3-4) Christ, too, brandished a whip against the moneychangers trespassing in the Temple. (John 2:15)

Love, that great theological virtue, is not what we practice when we are driven to wage war. Rather, we practice the cardinal virtue of justice in defending our homeland and the Church that sanctifies it. 

Justice is classically defined as giving each his due. Its Latin root, ius (right), implies setting things and relationships in proper order in accordance with nature (that given to the human being and the cosmos) by Providence. Peace, too, is a form of justice, and the cry resounds: “No justice, no peace.” 

Every civilization has something to say about when war can be justified and what norms of conduct are appropriate during a war. While the Eastern Church has no just war doctrine per se but what has been called a “justifiable war tradition,” the Western Roman Catholic perspective is worth considering because it is not only the most well-defined consideration of the topic but the one that has informed those principles now enshrined in modern international law of war, as found in the U.N. Charter and the Geneva Conventions. The roots of this tradition are in pre-Christian philosophers like Cicero but reached their mature form only in Christian thinkers like Augustine and Aquinas.

In just war doctrine, the primary distinction to note is between ius ad bellum (“being just in going to war”) and ius in bello (“being just in conducting war”).

The ius ad bellum criteria are as follows: 

1. Just Cause, disposing that the provocation for going to war has to be sufficiently grave, e.g. aggressive attack that provokes self-defence or mass denial of basic human rights (as in the case of genocide or cruelly abusive tyranny).
2. Comparative Justice means that one party has suffered a greater violation of justice that has to be set right than the other. It may be that each engages in unjust acts towards the other but one is more at fault, just as in a schoolyard scuffle one party bears greater responsibility for instigating the fight.
3. Legitimate Authority is based on the fact that only a publicly recognized and constituted body, usually a government, can be justified in waging war. It may seem that this puts rebels at a disadvantage, as it does, yet they may argue that the authority of the state against which they rebel has become illegitimate.
4. Right Intention, or the restriction of force to the purpose of the just cause. If one pretends to go to war for a justifiable reason but, in reality, baser motives like economic or political advantage are in the driver’s seat, the war is not truly just.
5. Probability of Success, whose self-explanatory definition states that the military action has to have a chance of succeeding. It can’t be just if it is a futile effort or one that requires extreme conduct for a victory to be possible.
6. Proportionality clarifies the previous principle as guiding that the good achieved by going to war has to be greater than the anticipated damage. A disproportionate force or futile effort violates this principle.
7. Last Resort, through which all peaceful means of resolving the dispute between the parties must have been tried in earnest and failed. Given how destructive war can be, it ought never to be the first or even the second resort. 

When we come to ius in bello, the principles are only three: 

1. Noncombatant immunity (or discrimination)
2. Proportionality
3. Right Intention

You’ll notice that two of the three repeat what was said in ius ad bellum, though they take on a different meaning when war is actually underway.

Noncombatant immunity means that one can only attack those who intend to fight on the field of battle. Civilians cannot be direct targets of attack, even though they may be key to the enemy’s supply lines and economic strength. This is a key difference from total war, where whatever means are needed to break the psychological will of the enemy to keep fighting may be employed.

Proportionality means no more force than is necessary should be used to achieve military objectives. So, do not use a machine gun where a shotgun will do or a bomb where a rifle will do. This has something to do with the virtue of prudence. If your weapons are more powerful than they need to be, or your targeting is imprecise, and civilians get caught up in the crossfire, you have a problem of justice as well. This is a big part of why deploying chemical, biological, or nuclear weapons is now considered a war crime.

Right Intention means that, even in the heat of battle, you must never lose sight of the aim you set when intervening, which is to establish a just peace. Taking revenge or becoming mad with bloodlust are vicious surges of the passions that often occur in wartime; they are never virtuous. 

As clear as these principles are, to which most reasonable persons will readily assent, they get muddied in the fog of war.

The realist may object that war is a state of exception where our usual scruples do not apply, and pretending they do is to tie our hands to the advantage of those willing to fight dirty.

The pacifist may object, in descriptive though not normative agreement with the realist, that in practice, combatants advert to total war, such that just war principles function as moral camouflage; moreover, a peace established by force of arms rather than by reconciliation is fragile and fails to include the aggressor in the community of moral agents.

These are serious objections, and on a purely pragmatic basis, it may be true that either total war or nonviolent resistance is more effective in a given case. With ongoing armed conflicts in Eastern Europe and the Middle East, as well as violent unrest in Latin America, these simple principles should be more than adequate tools you need to make judicious factual and ethical assessments about these events.