7/1/2026
When we moved from Kansas to the New York area, I had to part with many of my books. One of them was The History of the Peloponnesian War by Thucydides. I had intended to read it for years, partly because of the now-popular phrase "the Thucydides Trap," but never got around to it.
Recently I borrowed Donald Kagan's The Peloponnesian War from our local library. As I read it, something other than the geopolitical lessons captured my attention. I came across one of Thucydides' most famous observations:
"War is a violent teacher; it brings most people's characters down to the level of their circumstances."
The more I read, the more I understood what he meant.
According to Kagan, the Peloponnesian War devastated Greek society. It destroyed lives and property, intensified political and class divisions, fractured alliances among the Greek city-states, and ultimately weakened their ability to resist conquest from outside.
Even more striking was the brutality the war unleashed. As the conflict dragged on, anger, fear, and the desire for revenge steadily eroded the restraints of civilization. Prisoners were maimed or killed. Some were thrown into pits to die of thirst and starvation. Others were cast into the sea to drown. Innocent children were murdered. Entire cities were annihilated—the men executed, the women and children sold into slavery. During periods of civil war, fellow citizens slaughtered one another for days on end.
Violence also transformed the moral fabric of society. As Thucydides observed, words themselves changed their meaning. Reckless audacity came to be praised as courage, while moderation was dismissed as weakness. Religion lost much of its restraining influence. Truth and honor disappeared. Trust collapsed as communities became divided into hostile factions.
That is the deeper meaning of Thucydides' famous observation.
He is not arguing that human beings are inherently evil. Rather, he is suggesting that extreme circumstances profoundly change human behavior. In times of peace, people can afford to be generous, patient, civil, and principled. But during war, famine, or social upheaval, fear, deprivation, and uncertainty push many people toward actions they would previously have considered unthinkable. As he put it, war becomes "a violent teacher," bringing people's character down to the level of their circumstances.
Reading this passage inevitably brought to mind China's Cultural Revolution.
Although the two events were very different in their historical origins and political contexts, the patterns of human behavior show striking similarities.
The first is the breakdown of the most basic moral restraints.
Thucydides observed that prolonged conflict changes not only people's behavior but also their moral standards. Actions once regarded as shameful come to be accepted—even celebrated—because the surrounding circumstances have changed.
The Cultural Revolution displayed a similar pattern. Children publicly denounced their parents. Students relentlessly attacked their teachers. Friends informed on friends. Neighbors turned against neighbors. Behaviors that would have seemed unimaginable only a few years earlier became normalized under intense political pressure.
The people themselves had not suddenly become different. Rather, the environment had changed—and with it, what society rewarded, tolerated, or demanded.
The second similarity lies in the transformation of language.
Thucydides wrote that "words had to change their ordinary meaning."
Political labels became weapons. Virtues and vices were redefined according to factional loyalty.
The same phenomenon can be seen during the Cultural Revolution. Terms such as "revolutionary," "counterrevolutionary," "bourgeois," "class enemy," and "capitalist roader" acquired enormous political power. Language no longer merely described reality; it defined loyalty, determined guilt, and justified violence and persecution.
Once language changes, people's perception of reality often changes with it.
Think of this timeless question: What happens to ordinary human beings when the structures that sustain civilization begin to collapse? That's the question Thucydides was asking 2,400 years ago, and it's why his work still feels remarkably modern.
I'll continue exploring these parallels tomorrow.
