In the flood of commentary, four points, so far as I know, have not yet been made.

1. There were erroneous reports, last week, that one of the brothers was educated at Boston Latin, the nursery of Emerson, Santayana, etc. This may explain why some of the early accounts evoked a pair of intellectually gifted young men, somewhat in the mold of Nathan Leopold and Richard Loeb, the youthful nihilists who, having been seduced by the Nietzschean idea of “living dangerously,” murdered a boy in Chicago in 1924.

But the early impressions were wrong. The brothers Tsarnaev, it seems, were not gifted prodigies who took to heart Nietzsche’s Zarathustra or Nechayev’s Catechism of a Revolutionary and ended up reenacting Crime and Punishment. Far from resembling the brilliant Bazarov, the nihilist in Turgenev’s Fathers and Sons who wants to “smash people,” Tamerlan Tsarnaev, the older of the brothers, would seem to have been what Hannah Arendt called a “joiner,” a misfit who makes up for his directionless emptiness by embracing a mass cause, in this case militant Islam. Such an individual converts not out of an excess of spiritual intensity or intellectual pride but from ignorance, and comes to his creed less through study and reflection than through happenstance and chance acquaintance.

2. Much has been made of the brothers’ Chechen heritage, yet it is significant that, in becoming apostles of violence, they showed themselves to be more sympathetic to Salafist jihadism, with its roots in the Arabian peninsula, than to the traditional Sufism of Chechnya, which, perhaps because of its mystic preoccupation with the inner spiritual life, has long been associated with tolerance and accommodation. It is probable, then, that Tamerlan reached the dogmas that led him to terror not through inquiry into his heritage and roots, but through the offices of a zealot of one of the Qutbist or Salafist schools, a charlatan who took advantage of Tamerlan’s very vacuity and gullibility. As I write, there are reports that the FBI is seeking a “sleeper cell” to which the brothers were connected, a development that, if true, makes it even more likely that they were recruited by fanatics.

I would call it the banality of jihad, if the notion of “banality” did not seem to let the killers off the hook. This was the great objection to Hannah Arendt’s portrayal of the banality of Adolf Eichmann in Eichmann in Jerusalem. Her account of Eichmann’s stupidity seemed to diminish not only his monstrousness but even his culpability:

It was essential that one take him seriously, and this was very hard to do, unless one sought the easiest way out of the dilemma between the unspeakable horror of the deeds and the undeniable ludicrousness of the man who perpetrated them, and declared him a clever, calculating liar — which he obviously was not. . . . Despite all the efforts of the prosecution, everybody could see that this man was not a “monster,” but it was difficult indeed not to suspect that he was a clown.

The brothers Tsarnaev might, like Eichmann, have been clowns. But evil is not the less monstrous for being low-witted.

3. The original marathon — the race Pheidippides ran to bring to Athens the news of the Greek victory over the Persians — took place on the fault line between two civilizations. John Stuart Mill said that, had Darius prevailed, the civilization of Europe and the West would have been nipped in the bud. “The battle of Marathon,” he wrote, “even as an event in English history, is more important than the battle of Hastings.”

Had the Persians gained the victory at Marathon, the new forms of individualism and freedom that developed in Athens in the fourth and fifth centuries b.c. might have been crushed, and what Arendt called the “conformism, behaviorism, and automatism” of Persia might have prevailed. In fact, the novel freedoms of Greece survived, however imperfectly, in the West, and over time a spiritual culture that insisted on the value and dignity of every individual enlarged and extended them.

Today much of the world has embraced these freedoms, or is trying to. But Monday’s bombings suggest that the differences between East and West remain profound, however impolitic it may be to say so. It is only natural that we are as proud of our own free and tolerant society as Pericles was of the freedoms of Athens, that “city open to all the world.” But there is a tendency to complacency in our self-satisfaction; liberty, after all, is the exception, not the rule, in human history, and our own could quite easily disappear. I doubt the bombers were conscious of the historic meaning of the marathon they attacked, but the ease with which they repudiated the freedoms that Marathon stands for and that all subsequent marathons commemorate should give us pause, particularly if, as seems all but certain, the Tsarnaev brothers were the culprits. For they had benefited, in America, from this free way of life and still they turned against it.

4. “It had been good for that man if he had not been born.” The hellishness of what the bombers did brought to mind that Biblical sentence, as terrifying as any. But another sentence from the same book also came to mind, one that is easy to forget at a time like this and hard, perhaps impossible, to live up to when our chief concern is to defend ourselves against those who are trying to destroy our way of life. That is why it is all the more necessary to keep in mind. “But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them who despitefully use you, and persecute you . . . ”

— Michael Knox Beran, a lawyer and contributing editor of City Journal, is author of, among other book Forge of Empires, 1861–1871: Three Revolutionary Statesmen and the World They Made.