The conference at Hamilton College in upstate New York was to have convened to discuss "The Limits to Dissent," but it was canceled. The limits, it seems, can be quite narrow. That's unfortunate, for when Americans hear and debate opinions, no matter how odious or illogical, democracy is strengthened.

The furor in this case was prompted by the scheduled appearance of Ward Churchill, chairman of the ethnic studies department at the University of Colorado in Boulder. Churchill, an activist who claims to be Native American, is a man whose reason appears to have been blinded by his anger at injustice.

He wrote a despicable essay shortly after the Sept. 11, 2001, attacks. In it, he called the "technocratic corps" working in the World Trade Center "little Eichmanns" who, like the Nazi architect of the plan to exterminate the Jews, helped America's financiers enslave the world's poor and starve Iraqi children. The terrorists? He called them "combat teams" and likened them to freedom fighters.

Inflammatory words? Yes. And free speech does not guarantee the right to shout "Fire" in church. But it does allow anyone to voice obnoxious opinions that make people burn with anger. Those who, on free speech grounds, defended the right of Nazis to parade through a Skokie, Ill., neighborhood that was home to Holocaust survivors were right. So are those who defend the right of military recruiters to make their case on campus and those who support Churchill's right to speak at colleges.

Few were aware of how extreme Churchill's views were until a Hamilton professor discovered his obscure 9/11 essay on the Internet and called attention to it. Though repulsed by its message, Hamilton's president, Joan Hinde Stewart, rejected calls to rescind Churchill's invitation.

But that was before Bill O'Reilly, a rightwing Fox TV shout show host, picked up the story. O'Reilly profiled Churchill as one of many professors who are defiling the minds of America's youth. As if O'Reilly weren't doing his part.

O'Reilly irresponsibly listed Stewart's name and address and asked listeners to contact her. Fearing for the safety of both Churchill and those at her school, Stewart canceled Churchill's speech.

The right thing to do would have been to hire extra security or to hold the panel via closed-circuit TV. Instead, the mob won. In short order, other colleges, including Wheaton in Massachusetts and Eastern Washington University, canceled Churchill speaking engagements.

Churchill stepped down as the chair of his department in hopes of defusing the situation. He remains a tenured professor, although Colorado's governor is trying to get him fired because he is a public employee.

And the Wall Street Journal, in an editorial, suggested that Hamilton alumni punish their alma mater for even thinking about inviting Churchill. The paper encouraged them to boycott the college's capital campaign.

So much for freedom of thought.

Universities, above all, should not be places where only the "right" ideas can be discussed. Controversial beliefs provoke thought and debate. Among those who understand that are the current and former students of Churchill who disagree with his views but support his right to voice them because he forced them think.

We're not arguing that money, especially public money, be spent to give every crank a forum. But the healthiest and most educational way to deal with offensive and even dangerous ideas is to air them and rigorously challenge them.

Those who sought to censor Churchill because they loathed his views taught students the wrong lesson.