New Yorkers are accustomed to all sorts of strange outbursts and opinions, but it is hard to recall any as bizarre as those expressed by Ward Churchill, a professor of ethnic studies at the University of Colorado. After he was invited to speak at Hamilton College in upstate New York, someone noticed an essay he had written three years ago in which he sneered at the victims of the World Trade Center attacks, comparing them to Nazi official Adolf Eichmann. In the same essay, he urged that Bill Clinton, Madeline Albright, George H.W. Bush, Colin Powell, and Henry Kissinger be hanged as war criminals.

Mr. Churchill, who describes himself as a Keetoowah Band Cherokee and a leading activist of the American Indian Movement, argued that those who died in the World Trade Center were aiding the American economy, which made them complicit in our nation's alleged crimes against the Iraqis, the Palestinians, American Indians, and everyone else who had ever been "oppressed" by America. He did not make exceptions for rescue workers, restaurant personnel, or foreign staff. In his eyes, they were all equally guilty of serving our greedy capitalist society (the same society, it should be noted, that pays Mr. Churchill's salary at the University of Colorado).

The revelation of Mr. Churchill's vicious comments about the September 11 victims unleashed a rapid-fire series of events. First, the president of Hamilton College, Joan Hinde Stewart, staunchly defended the college's invitation to Mr. Churchill to discuss American Indian activism, as an exercise of academic freedom. A day later, the president canceled the event because of fear of violence on campus.

At first glance, the issue appears to be a straightforward test of free speech. Should Mr. Churchill have the right to express his opinion that the victims of September 11 deserved to die because of their willing participation in the American empire?

But the plot thickens. After Hamilton College canceled Mr. Churchill's appearance, the American Indian Movement's Grand Governing Council issued a press release stating that he "has fraudulently represented himself as an Indian." The leaders of the American Indian Movement say that Mr. Churchill "has been masquerading as an Indian for years behind his dark glasses and beaded headband." Furthermore, they denounced Mr. Churchill's "loathsome remarks" and "hateful attitude."

Suppose that the leaders of the American Indian Movement are right and Mr. Churchill is a phony. Does he still have the right to express his loathsome opinions? In my view, he does. It is one of the glories of our civilization (Mr. Churchill to the contrary) that anyone can say anything so long as they don't yell the equivalent of "fire" in a crowded theater.

The real issue is: How did a man with such hateful views win tenure at the University of Colorado? This question goes to the heart of the academic enterprise. Does a university have a responsibility to make certain that the men and women who are hired and promoted on its faculty are well qualified, base their academic work on evidence and reason, and express themselves with civility?

Much as the university claims to defend free speech without regard to its content, there are clearly limits and boundaries. It is hard to imagine any great university hiring a historian who dressed in Nazi garb and wrote an obsequious biography of Adolf Hitler. It is hard to imagine a great university granting tenure to someone who advocated the forced sterilization of certain races or of people with below average intelligence. It is impossible to imagine a university biology department hiring a professor who endorsed the literal truth of the Biblical story of Creation and denied evolution.

When I went to college in the late 1950s, the professors in every department strived to expose students to debates and issues. We students seldom knew our professors' own opinions, because they didn't express them. We never knew whom they intended to vote for or even what party they belonged to. They insisted that we think but they never told us what to think. Today, however, many academics believe that they have a right and even a duty to proselytize for their political opinions. Since the Vietnam War, academics have become accustomed to signing political petitions, endorsing candidates, and advocating their views forcefully in class.

Rather than operating in accord with the principle of academic freedom, the university today excludes right-wing extremists, while left-wing extremists are likely to be hired, promoted, and eventually tenured. Both ends of the ideological spectrum should be judged by the same standards of scholarship.

This is the atmosphere in which a man with such crackpot ideas as Mr. Churchill is not only a tenured professor, but chairman of the ethnic studies department (though he resigned when the controversy erupted).This is the same atmosphere in which a distinguished university, Columbia, finds itself charged with political bias in its Middle Eastern studies department.

Of course, Mr. Churchill should be free to speak his mind. I would like to see him address an audience of New York City police officers and firefighters or the families of September 11 victims. He is of little consequence and in a few weeks or months will be forgotten.

But what will remain as a problem for our society is the political atmosphere on many American campuses, where zealots like Mr. Churchill are hired and tenured, ever after free to inflict their one-sided rants on their hapless students.

Fortunately, extremist professors are still a rarity in American higher education. They usually turn up in departments of ethnic studies, gender studies, and other departments devoted solely to grievance groups.