From Purdue University president Mitch Daniels's May 12 commencement address (Wall Street Journal, Notable and Quotable, May 19):

The last few Mays, I've found myself issuing the same caution to each departing class.  I've pointed out that ... they are now aristocrats ... a new aristocracy of a knowledge economy, with membership conferred by unusual cognitive skills, augmented by a superior education, like Purdue's.

Because members of this hierarchy tend to work, dwell, and socialize with each other, marry each other, and have children just like each other's children, they unintentionally segregate from their "less blessed, less well educated fellow citizens."

Daniels urges graduates to resist this tendency.  "It's a shame to go through life with a narrow range of human interactions, and all one can learn from those who are different."

But, he warns, there is a more worrisome dimension to this self-segregation.

It's no longer just a matter of Americans not knowing and understanding each other.  We've seen these clusters deepen, and harden, until separation has led to anger, misunderstanding turned into hostility.

When individuals form tribes for survival and respond violently to the presence of outsiders, anthropologists call this phenomenon "tribalism."

Ambrose Bierce's 1913 "Ashes of the Beacon: An Historical Monograph Written in 4930" portrays a world where self-segregation descends into tribalism and anarchy.

Of the many causes that conspired to bring about the lamentable failure of "self-government" in ancient America the most general and comprehensive was, of course, the impractical nature of the system itself.

To us today it is clear that the word "self-government" involves a contradiction, for government means control by something other than the thing to be controlled.  When the thing governed is the same as the thing governing there is no government, though for a time there may be ... a considerable degree of forbearance, giving a misleading appearance of public order.

When men perceive that nothing is restraining them but their consent to be restrained, then at last there is nothing to obstruct the free play of that selfishness which is the dominant characteristic and fundamental motive of human nature and human action respectively.  Politics ... becomes a struggle of interests, and its methods are frankly serviceable to personal and class advantage.  Patriotism and respect for the law pass like a tale that is told.

Anarchy, no longer disguised as 'government by consent,' reveals his hidden hand.

The result?

In the end, "all the horrors incident to intestinal wars ... had so exhausted ... the surviving protagonists of legitimate government that they could make no further head against the inevitable, and were glad indeed ... to accept life on any terms that they could obtain" from the "gracious sovereign."

Daniels references one essayist who wrote, "Tribalism is the default human experience[.] ... The notion of living alongside people who do not look like us and treating them as our fellows was meaningless for most of human history."

Does today's identity politics augur an American dystopia?