From Thomas Aquinas to Clausewitz, the idea of just war evolves into a doctrine where political necessity displaces moral judgment.
In the previous article we referred to the concept of just war, first suggested by Saint Augustine and later transformed into doctrine by Thomas Aquinas, whose formulation requires a competent authority to declare war, that those attacked deserve it because of some fault, and a right intention, meaning that the purpose must be to promote good or prevent evil.
The one who holds that initial requirement of authority is the prince.
A feudal lord in dispute with another should not attack him directly, but submit the cause of the dispute to a higher authority.
The medieval world was a theological unity whose head was the Pope.
Once that unity was fragmented as a consequence of the Reformation, the Pope ceased to be the supreme arbiter.
Various regions no longer recognized his authority and therefore did not all accept that doctrine on war.
What Aquinas had sought to prevent was thus dissolved.
Now Christians would fight against Christians.
In 1532, Machiavelli published his best-known work.
In The Prince, he separates morality from the action of government.
His prince does not act in terms of good or evil, but in terms of convenience.
Yet this was nothing more than an observation of the reality of his time.
When he advises the prince not to abuse the women of his subjects nor seize their property, it is because “men forget sooner the death of their father than the loss of their patrimony.”
Later he insists on the point because such conduct prevents the ruler from becoming hateful.
“Most men live contentedly so long as they are not deprived of their property and honor.”
Such conduct, he says, prevents conspiracies.
For not being hated by one’s people is among the most effective remedies.
And although the advice is given from the prince’s point of view, it is no less beneficial for the subjects.
Regarding just war, Machiavelli says, quoting the historian Livy, who in turn quoted Gaius Pontius: “War is just when it is necessary, and arms are merciful when there is no hope except in them.”
The meaning is understood to be that other means must be exhausted before necessity arises to justify war.
But defining when war is truly just and necessary is left to the judgment of political leaders.
Clausewitz takes up the idea of war as a continuation of politics, prefigured by Machiavelli.
But that does not sanctify it.
In On War he writes: “Many philanthropic minds might imagine that there is a way to disarm or defeat an adversary without excessive bloodshed. This is a false conception and must be rejected.”
False ideas born of sentimentalism are always the worst.
Whoever shows no restraint before bloodshed will gain advantage over the adversary.
Clausewitz states this because, he says, the theoretical concept of war is the destruction of the enemy.
And then where would that just war spoken of by Aquinas remain?
“War is an act of force, and there is no limit to its application.”
Since that is also the aim of the adversary, neither side is master of itself: each justifies the other.
Nevertheless, since war was regarded as a matter for gentlemen, violence was regulated by codes of ethics.
These unwritten rules required that prisoners not be mistreated and that their rank and honor be respected.
Civilians were not to be intentionally attacked.
When Clausewitz compares war with a duel, he assumes by analogy the customary rules governing affairs of honor.
It was in Geneva in 1864 that the first convention was signed, giving legal support to the International Committee for Relief to the Wounded, created one year earlier by Henry Dunant.
But history continues.