Even most eloquent speakers can fail commencement duty. (Signs of Summer).

WITH the passing of Memorial Day weekend, a dark gaseous cloud has begun to lift from the American continent. The cloud starts to form every year in late April and thickens in the first weekends of May, until by mid-month the fumes endanger anyone within 20 miles of a college campus.

The source is easily traceable: it is the college commencement address.

Not everyone finds commencement addresses unwholesome, of course. The people who deliver them, for instance, seem to enjoy them much more than the people who are forced to listen. Then there are such specialists as Peter J. Smith, who was so taken with the genre that two years ago he published a collection called "Onward!"

"The commencement speech differs from any other type of speech," Smith writes. "They instruct. They reflect. They exhort. They persuade. They reassure. And they inspire."

Smith's language here is almost as inflated as the typical commencement speech, but he's right about one thing. Even when they fail, as they usually do, to reassure, persuade or inspire, commencement addresses can tell us something about the spirit of the age.

I asked Aram Bakshian, the editor of American Speaker newsletter and a speechwriter to U.S. Presidents Nixon, Ford and Reagan, why the average speech is so insufferable--turgid on the one hand or painfully cute on the other.

Bakshian's answer was simple. Commencement speakers tend to forget the most elementary rules of speechifying.

"Keep it short," Bakshian said. "Use local references so the audience knows you know something about the school you're addressing.

"But above all, remember: This is about them, not about you."

This last must be the hardest rule to remember. Something happens to people when they are invited to address commencements. They may be giants of commerce, statesman or the lesser lights of politics, generous donors to alumni funds or stars of half-forgotten sitcoms. But put an honorary diploma in their hands and they rear up like great billowing smokestacks, releasing plumes of platitudes.

"The greatest of your accomplishments are still before you. Go forth and seek them, give flight to your dreams, take hold the reins of destiny." (And don't forget to mix the metaphors!)

I'm quoting from Sen. Daniel Inouye--an otherwise admirable public servant who had the misfortune to exhale this commencement address in 1992--but it's not fair to pick on him alone. Similar banalities gum up almost every commencement speech of the past 40 years.

"Success can be a trap," the playwright Nell Simon told graduates of Williams College 20 years ago. "This country and our culture glorifies and deifies the goddess Success. Do not listen to that kind of thinking."

You hear less and less of this at commencement ceremonies these days, perhaps because graduates have noticed the flaw in logic. If the speakers themselves had taken time to smell the roses and avoid overwork and place family before all else, they never would have gotten rich or famous enough to be asked to be commencement speakers.

So the banality has evolved. The most widely reprinted commencement address of recent years was delivered in 1999 by the novelist and columnist Anna Quindlen.

"Begin with a clean slate," Quindlen told Mount Holyoke College graduates. "Then look, every day, at the choices you are making, and when you ask yourself why you are making them, find this answer: for me, for me."

Trite, sure: but has there ever been a purer expression of the worldview of the Baby Boomer elite?

Andrew Ferguson is a columnist for Bloomberg News.