From the Chronicle of Higher Education's philosophy columnist:

Us v. Them: Good News from the Ancients By Carlin Romano

"Us against them" seems a staple of human psychology ... Looking through a recent New York Times, you couldn't help thinking that the notion merits a separate daily section to organize stories efficiently: North Korean vs. South Korean, North Ivorian vs. South Ivorian (those hard geographical divisions help), e-book reader vs. traditional book lover, New York Giant vs. Dallas Cowboy, boomer vs. Gen X'er, man vs. woman.

Are we just boringly binary?

As opposed to excitingly unitary? This shouldn't be news to a professor of philosophy, but contrast is the essence of information. You can turn data into a stream of 1s and 0s, but you can't turn it into a stream of all 1s.

And why, as both Rodney King and distinguished science writer David Berreby asked, for different reasons, can't we all get along? Back in 2005, Berreby tried to open our eyes on the subject with his noncontentiously titled Us and Them: Understanding Your Tribal Mind (Little, Brown and Co.). We can't help being tribal thinkers, Berreby explained, because organizing other humans into kinds is "an absolute requirement for being human." It is, he wrote, "the mind's guide for understanding anyone we do not know personally, for seeing our place in the human world, and for judging our actions." There is "apparently no people known to history or anthropology that lacks a distinction between 'us' and 'others,'" and particularly others who don't rise to our level.

Our categories for humans, Berreby elaborated, "serve so many different needs, there is no single recipe for making one." Categories for other people "can't be understood objectively." We fashion them in classic pragmatic style to suit our purposes in solving problems,

The notion that objectivity and pragmatism are obviously at odds is a curious one.

... particularly that of generalizing about people we know by only a feature or two. We make these categories-often out of strong emotional need. We don't discover them. American suburbanites need "soccer moms," Southern kids need "Nascar dads," Yemenites need neither.

Those are obviously silly examples of the horrors of Us v. Them thinking, in part because there was never any Us in them. The categories "soccer moms" and "Nascar dads" weren't dreamed up out of strong emotional needs by soccer moms and Nascar dads, they were cold-bloodedly invented by marketing researchers and political consultants to help their clients succeed focus their marketing better for inchoate groups of indivduals who had certain tendencies in common.

... "The issue," Berreby observed, "is not what human kinds are in the world, but what they are in the mind-not how we tell Tamils and Seventh-day Adventists and fans of Manchester United from their fellow human beings, but why we want to."

Well, uh, if you can tell that person you are talking to is a fan of Manchester United, you might want to compliment Wayne Rooney on his superlative soccer skills. If you can tell that person is a fan of one of Manchester United's rivals, however, you can feel free to mention Wayne's face.

Look, the motto of Faber College in Animal House offers words to live by: Knowledge is good.

Is it too hard to notice that there are differences between people, that these differences ("diversity!") make humanity infinitely more interesting than if we were all a homogeneous mass; and that noticing differences accurately is useful?

True enough. The problem remains that this habit of hostility to the "Other" seems inescapable, even if it's not hard-wired into us. We've been talking like Tarzan since the ancient Greeks. Me Athenian, you barbarian. Me Roman, you Carthaginian loser. Me Greek, you dumb Egyptian animal worshiper. Me better, you worse.

Again, as with Berreby's study, a book can help us if not save us-a small tool to pry the fetishisms of "Us vs. Them" from our minds. Rethinking the Other in Antiquity, by Erich S. Gruen, out this month from Princeton University Press, like all excellent scholarship massages the mind in useful new directions. Gruen, a Berkeley professor emeritus of history and classics, wields his command of ancient sources to shake a widely shared historical belief-that ancient Greeks and Romans exuded condescension and hostility toward what European intellectuals call the "Other." For those Greeks and Romans, that largely meant peoples such as the Persians, Egyptians, and Jews. Even if Gruen doesn't wholly convince on every ground that Greeks and Romans operated like Obamas in togas, regularly reaching out to potential enemies, his careful readings of Aeschylus, Herodotus, Tacitus, and others introduce us to a kinder, gentler ancient world. His analysis confirms how even back then, tossing people into a category and then hating them en masse was a choice, not an evolutionary necessity.

Gruen doesn't deny the transhistorical phenomenon of "Us vs. Them" itself. "The denigration," he writes at the outset, "even demonization of the 'Other' in order to declare superiority or to construct a contrasting national identity is all too familiar." What bothers him is the degree to which analysis of "such self-fashioning through disparagement of alien societies" has become "a staple of academic analysis for more than three decades" (he respectfully mentions Edward Said's Orientalism and the progeny it sparked), rendering the factual phenomenon under examination too unquestioned.

As a result, Gruen reports, works of classical scholarship such as Fran?§ois Hartog's The Mirror of Herodotus (University of California Press, 1988) and Edith Hall's Inventing the Barbarian (Oxford University Press, 1989) leave us with the firm understanding that "negative images, misrepresentations, and stereotypes permitted ancients to invent the 'Other,' thereby justifying marginalization, subordination, and exclusion." A natural conclusion when it comes to "Us vs. Them," Gruen writes, is that "the ancients are thus to blame."

The concept of Projection suggests that the people who are really filled with Who? Whom? hatefulness are the post-modern academics who are always denouncing it in others.

Far from rejecting evidence for the standard view, Gruen helpfully sums it up: "Jewish writers excoriated Egyptians for zoolatry and shunned admixture with Canaanites, Ammonites, Moabites, and Philistines. ... The Romans scattered their biases widely with negative pronouncements on easterners and westerners alike. They dismissed Greeks as lightweights ...

The Romans conquered the Greeks and ruled them from 500 years, but they continued to take cultural direction from the Greeks. A better case could be made that the Romans were too in awe of the Greek cultural contributions, which slowed them down from coming up with more of their own.

Gruen's mission, however, is to unpack the contrary story, far less told: "that Greeks, Romans, and Jews (who provide us with almost all the relevant extant texts) had far more mixed, nuanced, and complex opinions about other peoples."

His examples span the ancient Mediterranean and beyond. In his opening chapters, he concentrates on four pieces of evidence-Aeschylus's Persae, Herodotus's treatment of the Persians, Xenophon's Cyropaedia, and our knowledge of Alexander's cooperation with the Persians-using them to reject the "prevailing scholarly consensus" that Greeks held a consistently negative image of Persians. ... Gruen says his aim is to show that "the descriptions and conceptualizations, far from establishing simplistic stereotypes, display subtle characterizations that resist reductive placement into negative (or, for that matter, positive) categories."

You could flip through Herodotus's Histories (which are a sort of sprawling travel book that eventually resolves into a history of the Greco-Persian Wars) for 20 minutes and come to the the same conclusion. The Greeks were really proud that they beat the Persians in 490-480 BC because the Persians were the top dogs. Herodotus's Greek audience was very interested in learning more about the rich and powerful Persians.

Perhaps, someday, revisionists scholars might sit down and carefully read, say,The Bell Curve and Human Accomplishment and notice their similar judicious nuance.

On the other hand, it's essential to remember that Herodotus's division between Oriental despotism and Occidental liberty was part of the Greatest Leap Forward in human thought. The confidence the Greeks gained from defeating the Persians at the beginning of the 5th Century, from the notion that they were not just different but better than the superpower of the era and that they should emphasize their differences, helped set off the most concentrated age of human accomplishment ever.

Rather, his point is that the ancients, like us, enjoyed options in how they categorized others, drew upon others, and defined them in the process of shaping their own cultures. They sometimes chose-more often than one realized before reading Gruen's book-to do so in a spirit of admiration and respect. Contrary to much received opinion, we have some classical role models in resisting "Us vs. Them."A simple line, in Obama's Tucson memorial speech, captured the existentialist antidote to that ugly psychological strain.

"We may not be able to stop all evil in the world," the president said, "but I know that how we treat one another is entirely up to us."

We also get to decide how we categorize one another. And who we include in "us." If we included everyone, what might follow from that?

Ignorance.

This is not a sophisticated point but it eludes philosophers when thinking about human beings — categorization is essential to knowledge, the solution to bad stereotypes are better stereotypes — but it's one that gets lost all the time when intellectuals try to think (or, more precisely, to not think) about race.