I used to believe that the world was essentially divided into twotypes of people: those who were broadly tolerant and those who feltthreatened by differences. If only the forces of tolerance couldwin out over the forces of intolerance, I reasoned, the world mightfinally know some measure of peace.

But there was a problem with my theory, and it was never clearerthan in a conversation I once had with a Pakistani friend who toldme that he loathed people, like President Bush, who insisted ondividing the world into "us" and "them." My friend, of course, wastaking an innocent stand against intolerance and did not realizethat, in so doing, he was in fact dividing the world into "us" and"them," falling straight into the camp of people he loathed.

This is a political version of a famous paradox formulated byBertrand Russell in 1901, which shook the logical foundations ofmathematics. Any person who claims to be tolerant naturally defineshimself in opposition to those who are intolerant. But that makeshim intolerant of certain people--which invalidates his claim to betolerant.

The political lesson of Russell's paradox is that there is no suchthing as unqualified tolerance. Ultimately, one must be able toexpound intolerance of certain groups or ideologies withoutsurrendering the moral high ground normally linked to tolerance andinclusivity. One should, in fact, condemn and resist politicaldoctrines that advocate the murder of innocents, that undermine thebasic norms of civilization, or that seek to make pluralismimpossible. There can be no moral equivalence between those whoseek--however clumsily--to build a more liberal, tolerant world andthose who advocate the annihilation of other faiths, cultures, orstates.

Which brings me to my son, Daniel Pearl. Thanks to the release of AMighty Heart, the movie based on Mariane Pearl's book of the sametitle, Danny's legacy is once again receiving attention. Of course,no movie could ever capture exactly what made Danny special--hishumor, his integrity, his love of humanity--or why he was admiredby so many. For journalists, Danny represents the courage andnobility inherent in their profession. For Americans, Danny is asymbol of one of our very best national instincts: the desire toextend a warm hand of friendship and dialogue to faraway lands andpeoples. And for anyone who is proud of their heritage or faith,Danny's last words, "I am Jewish," showed that it is possible tofind dignity in one's identity even in the darkest of moments.Traces of these ideas are certainly evident in A Mighty Heart, andI hope viewers will leave the theater inspired by them.

At the same time, I am worried that A Mighty Heart falls into a trapBertrand Russell would have recognized: the trap of moralequivalence, of seeking to extend the logic of tolerance a step toofar. You can see hints of this in the film's comparison of Danny'sabduction to Guantanamo--it opens with pictures from theprison--and its comparison of Al Qaeda militants to CIA agents. Youcan also see it in the comments of the movie's director, MichaelWinterbottom, who wrote on The Washington Post's website that AMighty Heart and his previous film, The Road to Guantanamo, "arevery similar. Both are stories about people who are victims ofincreasing violence on both sides. There are extremists on bothsides who want to ratchet up the levels of violence and hundreds ofthousands of people have died because of this."

Drawing a comparison between Danny's murder and the detainment ofsuspects in Guantanamo is precisely what the killers wanted, asexpressed in both their e-mails and the murder video. ObviouslyWinterbottom did not mean to echo their sentiments, and certainlynot to justify their demands or actions. Still, I am concerned thataspects of his movie will play into the hands of professionalobscurers of moral clarity.

Indeed, following an advance screening of A Mighty Heart, a panelistrepresenting the Council on American-Islamic Relations reportedlysaid, "We need to end the culture of bombs, torture, occupation,and violence. This is the message to take from the film." Themessage that angry youngsters are hearing is unfortunate: All formsof violence are equally evil; therefore, as long as one persists,others should not be ruled out. This is precisely the logic used byMohammed Siddiqui Khan, one of the London suicide bombers, in his2005 videotape on Al Jazeera. "Your democratically electedgovernments," he told Westerners, "continuously perpetuateatrocities against my people. ... [W]e will not stop this fight."

Danny's tragedy demands an end to this logic. There can be nocomparison between those who take pride in the killing of anunarmed journalist and those who vow to end such acts--no ifs,ands, or buts. Moral relativism died with Daniel Pearl, in Karachi,on January 31, 2002.

There was a time when drawing moral symmetries between two sides ofevery conflict was a mark of original thinking. Today, with Westernintellectuals overextending two-sidedness to reckless absurdities,it reflects nothing but lazy conformity. What is needed now is forintellectuals, filmmakers, and the rest of us to resist thisdangerous trend and draw legitimate distinctions where suchdistinctions are warranted.

My son Danny had the courage to examine all sides. He was a genuinelistener and a champion of dialogue. Yet he also had principles andred lines. He was tolerant, but not mindlessly so. I hope viewerswill remember this when they see A Mighty Heart.

By Judea Pearl; Judea Pearl is president of the Daniel PearlFoundation, an organization committed to interfaith dialogue, andco-editor of I am Jewish: Personal Reflections Inspired by the LastWords of Da