But Joseph Ellis is something else. He's a liar. In fact, thanks to investigative reporting by The Boston Globe, we now know that he's been telling some real whoppers for years now. The story is fascinating both in its own right and for what it reveals about how you impress people in our current political climate.

Ellis, you see, has been teaching a popular course on the Vietnam War and American culture in which he's been regaling students with tales of his Army experiences in 'Nam, and how the horrors he saw there turned him into an antiwar protester upon his return to Yale grad school. But it's all bogus. As the Globe reported June 18, Ellis was never in Vietnam; he spent the war on the East Coast, and his main military experience consisted of a few years on the history faculty at West Point.

Once the truth got out, Ellis 'fessed up. But he did it in that apology-which-isn't-really-an-apology style perfected by Bill Clinton. He issued a statement declaring that "even in the best of lives, mistakes are made" and expressed his "regret" over "having let stand and later confirming the assumption that I went to Vietnam."

Ah, so that's how it happened. People just somehow started assuming things, and he just didn't get around to correcting them, until he sorta kinda wound up confirming them. Oh well, doesn't matter all that much. Happens to the best of us.

So, apparently, does the age-old problem of keeping your stories straight. In two Globe interviews in the past few years, Ellis has said he was in Vietnam for a year early in the war (1965-66) as a platoon leader and paratrooper with the 101st Airborne Division. But in a class last year he said he was part of an infantry unit near My Lai just before the well-publicized massacre there in 1968.

In all his tall tales, Ellis achieved the desired impact on his wide-eyed students. "I think back to that course and recall how the war was a test of his manhood," recalled one senior, Erich Carey. "He had gone, taken the test of manhood, and passed it." Another senior, Peter Juran (in the Globe's paraphrase), "recalled Ellis talking about how he had served honorably in Vietnam out of a sense of duty."

Oh, and then there were all the colorful details. Ellis, said Carey, "told us about a fellow, a strong jock, a college football player, who was drafted and came to Vietnam. They were out in the field, and this guy was reading Emily Dickinson poems that brought him to tears."

With such a knack for what the Globe politely called "resumé embroidery," it comes as no surprise that Ellis hasn't confined this practice to 'Nam stories. Last year he told a Globe reporter that he scored the winning touchdown in the last high school football game of his senior year (the high school yearbook shows he wasn't on the team, which incidentally lost its last two games that season). He also may have at least exaggerated claims of his record as a civil-rights worker (those claims have inflated over the years), so you can't help but wonder when he tells yet more colorful tales of Mississippi police pounding on his door at night.

All this naturally raises questions about Ellis' accuracy as a historian. Interestingly, fellow academics who've delivered pro forma disavowals of his lies have gone out of their way to insist they're not questioning his professional work. But why not? If someone lies flagrantly and repeatedly in one area of life, it's silly to presume he practices rigorous honesty in another.

And as it happens, some of his most famous claims are hardly beyond question. Take the Jefferson story. In 1998, Ellis co-authored a Nature magazine article with a geneticist unambiguously titled "Jefferson Fathered Slave's Last Child," and basing its claim on a longtime rumor plus genetic similarities between descendants of Hemings and Jefferson. Ellis made much of the point, writing in U.S. News & World Report that the evidence proved the claim "beyond any reasonable doubt" and dismissing critics as "a few die-hard Jefferson worshippers."

I doubted the claim at the time, and not because I worship Jefferson (I regard many of his political ideas as wise, but his deist theology as abysmal). My first suspicions began with the all-too-convenient timing. Bill Clinton was in the midst of his Monica Lewinsky scandal, and the media quickly played up the angle that this just showed that, hey, great presidents do this sort of thing all the time. (Ellis himself, in U.S. News, wrote that Clinton "called one of the most respected character witnesses in all of U.S. history.")

My doubts were soon buttressed by an article in Chronicles: A Magazine of American Culture (where I had once worked). Among many other things it turned out that Jefferson and the part-white Hemings had relatives in common; she was half-sister to Jefferson's first wife. As for his side of the family, there were more likely candidates for fatherhood than Thomas; at least eight other men lived near the plantation, including promiscuous brother Randall, who liked to party with the slaves. Earlier this year, a commission of 13 academics issued a 535-page report on the Ellis claim, declaring their reactions "range from serious skepticism about the charge to a conviction that it is almost certainly false."

Now did Ellis set out to lie in this case? Though he's given us no reason to believe he's above it, I don't necessarily think so. But I also think his political biases played a role — probably a big one — in his conclusion. And I think that falsehood is what you get when people adopt the postmodern notion that what really matters isn't truth, but power — the value of a story in swaying an audience.

That's the growing worldview at most colleges, so it comes as no surprise that some academics are trying to excuse or mitigate Ellis' offenses. Sarah Lawrence College Professor Nicolaus Mills, after spending most of a New York Newsday commentary arguing for academic honesty, undermines most of his essay when he closes by saying he hopes Ellis doesn't heed calls to resign (he hasn't, so far) or have his career spoiled (the jury's still out). You see, "what he was searching for in making up stories about being in Vietnam was what many of us have long desired-a way of making autobiography as relevant to teaching as the life of the mind."

This isn't forgiveness; it's rationalization. It's also nonsense, and once you start down that road, there's no end to the absurdity. Of course, absurdity that's most common in academia has spilled out into the larger society. We see ample evidence of it every day, epitomized in the recent remarks of Dan Rather, who — in the course of arguing that Bill Clinton is a man of character — said "you can be an honest person and lie about any number of things." (Rather may be writing some of Ellis' dialogue: Confronted by a reporter about his lies, Ellis pronounced himself "an honorable man.")

Somehow I'm reminded of a passage Lewis Carroll wrote in Through the Looking-Glass: " 'When I use a word,' Humpty Dumpty said in a rather scornful tone, 'it means just what I choose it to mean — neither more nor less.' " Carroll was a great satirist in the 19th century, but his imagination might be wasted today. In the age of Ellis, Rather and Clinton, there may be no satire equal to the inanities that pass the lips of professors, anchormen and presidents.