So now we know. Based on a tip from an anonymous law professor and richly detailed literary sleuthing by Joseph Bottum in the October 4, 2004, issue of the Weekly Standard, Laurence Tribe is a plagiarist.

For his 1985 book, "God Save This Honorable Court," the prominent liberal Harvard Law School professor now acknowledges that he lifted direct passages and paraphrased others, all without proper attribution, from the 1974 book, "Justices and Presidents," by Henry Abraham, a now-retired law professor of the University of Virginia.

Bad thing, plagiarism. Arguably the worst offense any writer can commit. As Daniel J. Hemel and Lauren A.E. Schuker wrote in the Harvard Crimson this week, "Harvard’s Writing with Sources manual, which is distributed to all undergraduates when they enter as freshmen, offers a crystal-clear definition of plagiarism: ‘passing off a source’s information, ideas, or words as your own by omitting to cite them; an act of lying, cheating, and stealing.’"

Tribe apparently got outed because only several weeks earlier he publicly defended another Harvard Law School professor, Charles J. Ogletree, nabbed on the same charges, which offended the law professor who blew the whistle. Perversely, Tribe is now being defended by another of his Harvard Law School colleagues, Alan Dershowitz, who last year got stuck to the plagiarism tar baby for a while himself. A year before that, it was Harvard Overseer and historian Doris Kearns Goodwin who got caught for stepping over the line in her book, "The Fitzgeralds and the Kennedys."

Plagiarism is an act that, when exposed, may produce interesting explanations, but no acceptable excuse. Plagiarism is its own self-contained evidence, sort of like a thief writing his name on the swag bag. Plagiarism is like obscenity, you know it when you see it.

Plagiarism is not an inadvertent sentence or phrase here or there, not the coincidental similarities of numerous reports on the same subject, not "quoting" an obviously famous phrase for emphasis or humor or literary effect, not the occasional, isolated brain slip of writing something previously read and then stuck in the mind as one’s own. Those things happen all the time and most writers are chagrined even if they only privately realize they got too close to someone else’s work. Plagiarism is measured in chunks and patterns, by detailed analysis.

Professor Tribe is now in the process of doing the right thing, after getting caught doing the wrong thing, the prototypical path of repentance, genuine or otherwise. What’s even more interesting, however, are the three separate defenses being mounted by Professor Dershowitz on behalf of his colleague. Reported by the Harvard Crimson and the Associated Press, they are perhaps more revealing of the mindset at Harvard Law School than Professor Tribe’s plagiarism.

The first Dershowitz line (from AP) is that Joseph Bottum’s Weekly Standard article is "a political attack on the liberal scholar." It’s not; go read it. It’s an exhaustive piece of literary detective work. Professor Tribe is who he is politically, and that’s intriguing when all the dots are connected. But he’s also a plagiarist, shot, skinned and deboned by Mr. Bottum’s work.

Sometimes mentioned as a potential nominee to the Supreme Court, Professor Tribe is now unlikely to achieve that honor, not because he’s a liberal, but because he’s a plagiarist. The very same reason that U.S. Senator Joseph Biden withdrew as a candidate for President in 1987, after plagiarizing the speech of a British politician.

Professor Dershowitz’s second defense is that Henry Abraham knew about Professor Tribe’s plagiarism for 20 years and said nothing. "If he had a gripe, he should have written to Larry 20 years ago," Dershowitz told the Harvard Crimson.

Really, professor? Professor Abraham’s gentlemanly silence makes "an act of lying, cheating, and stealing" a lesser offense to what degree? In your learned legal opinion, of course.

Professor Dershowitz’s third defense, also revealed in the Harvard Crimson, is that standards for attribution in the legal profession are "murkier" than for other fields. That’s an interesting thought. We’ve never seen it written anywhere. Does it apply only to law professors or students as well? How about when lawyers with their murky standards decide to publish popular books against the much more clearly defined standards of mere writers? Did you mean to say "practices" rather than standards? We’d agree with that in a Cambridge minute and could fill a book with examples.

Well, never mind, Professor Dershowitz thinks Harvard should now establish stricter guidelines "so that scholars could avoid ideologically motivated charges of plagiarism in the future," again according to the Harvard Crimson, emphasis added.

With that logic, why bother with all the extra work? Just annotate Harvard’s Writing with Sources manual. After "lying, cheating, and stealing," add "except by liberal Harvard Law School professors who are caught by conservatives." The only problem we see with that is politicians and journalists demanding their own exceptions once they discover their own "murkier" standards.

Full Disclosure: The Center for Individual Freedom has been involved in legal cases in which Professor Tribe has also been involved as counsel. Depending upon the case, Professor Tribe has argued either in support of or in opposition to the positions taken by the Center. Terry Eastland, publisher of the Weekly Standard, is a Director of the Center for Individual Freedom Foundation.