The democratically elected government of Poland recently passed a bill that both attacks free speech and tries to conceal the complicity of some ethnic Poles in the Holocaust. “It would be illegal — and punishable by up to three years in prison — to claim Poland was complicit in the Nazi atrocities committed on Polish soil during World War II,” NPR reported.

Professor Robert George, one of America’s most respected conservative intellectuals and a Princeton icon, published an open letter declaring his opposition to the bill. “I wish to express my concern about proposed legislation that could restrict or have the effect of discouraging historical scholarship and freedom of speech concerning the Shoah and the death camps that the Third Reich placed on Polish soil,” he wrote.

It is fantastic that Professor George supports free speech and open discourse—his track record on that subject speaks for itself—and he is correct that this law’s criminalization of speech should be loudly condemned; however, it is not enough to defend free speech by itself. Open discourse is useless unless we also demand a recognition of facts. Professor George should have taken the opportunity in his letter to correct the ahistorical account of the Holocaust that the Polish government has implied. “Millions of non-Jewish Poles and others were murdered along with Polish Jews and Jews of other nationalities in the Shoah,” Professor George wrote in the letter, using a Hebrew term for the Holocaust. “It is to the credit and glory of Poland and the Polish people that so many Poles are among the rescuers and resisters who are honored as ‘Righteous among the Gentiles’ at Yad Vashem.”

It is correct that a tragic number of ethnic Poles died at the hands of the Germans. It is also correct that Yad Vashem, the Holocaust museum in Israel, recognizes 6,706 ethnic Poles who aided Jews during the Holocaust, more than in any other country. On the other hand, more Jews were murdered in Poland than any other country during the Holocaust, and there is significant evidence that the ethnic Polish population actively participated in the murder of Jews, particularly in the years between the German invasion and the construction of death camps. For example, a Princeton historian, Jan T. Gross, has written a book about the 1941 massacre of roughly 1,600 Jews in the Polish village of Jedwabne. According to Gross’ evidence, which he clearly lays out in his book Neighbors, the atrocity was not committed by German occupiers, but by the Jews’ Polish neighbors. Jedwabne is but one example of the well-documented participation by ethnic Poles in the slaughter of Jews during the Holocaust. Many scholarly estimates say that tens or hundreds of thousands of Poles actively participated in murdering Jews. This was not caused by German coercion—there was a long tradition of anti-Semitism in Poland, and the Polish population did not require much goading to kill their Jewish neighbors and expropriate their property. The suffering of Poles suffering neither precludes nor excuses complicity in genocide.

It seemed in certain parts of the letter that Professor George did not, in fact, recognize the extent of the crimes that were committed by ethnic Poles: “I understand and, of course, share the legitimate concern of your government not to have Poland and the Polish people, who so nobly resisted the Nazis and who suffered so greatly under their tyranny, falsely accused of crimes they did not commit.” This refers specifically to the death camps, which Poles did not play a significant role in operating. I worry that Professor George focuses too much on the death camps and does not recognize that the massacres committed by ethnic Poles are part of the same genocide as camps.

After Professor George posted the letter on his Twitter feed, I responded with a similar argument (albeit only in five tweets), and we discussed it a little. (Nobody should dispute that Professor George wholly supports open discourse.)

“It’s great that Professor George supports free speech and opposes this law,” I wrote at the start of the thread. “But it seems in the piece like he is almost accepting the false version of events put forward by the Polish government, that practically no ethnic Poles helped murder Jews during the Holocaust.”

“That is not true and I neither say nor suggest anything of the kind,” Professor George responded. “While there were Polish rescuers, and many, many Polish victims, there were also, as I expressly remind the Prime Minister, Poles involved in anti-Semitic acts, denunciations, and even the operation of camps.”

Professor George, to his credit, acknowledged in his letter that Poles were not totally innocent: “I’m sure you will agree, however, that it is also important for the truth to be told about the willing complicity of some non-Jews, including some who were Polish, in anti-Semitic acts, denunciations, and even the operation of the death camps.” Professor George’s language is too soft to accurately describe the history. “Some non-Jews, including some who were Polish,” feels like a pretty narrow category, especially when compared to “so many Poles” who helped Jews. The history is a little murky, but most experts agree that tens of thousands of Poles were involved with parts of the German-occupied Polish state that murdered Jews, and that there were plenty of other incidents of ethnic Polish civilians massacring Jews. “Anti-Semitic acts” seems to be a euphemism for “massacres,” and Professor George’s language seems to minimize the complicity of many ethnic Poles in the Holocaust. This is dangerous—in addition to restricting free speech, the purpose of Poland’s Holocaust law is to promote state propaganda in academic and popular discourse about the Holocaust. As an academic, Professor George should have strongly advocated for the truth of the matter in addition to free speech.

In a second tweet, Professor George reminded me of his support for free speech in Poland with a quote from his letter about the sanctity of “robust discussion and debate.” I do not object to Professor George’s love for free speech as a principle liberal virtue. In fact, I agree with it wholeheartedly, and government interference with speech should almost never be tolerated. My worry is that, in this instance, Professor George argued for free speech and forgot the need to advocate for truth. To have any useful effect, open discourse requires a fundamental devotion to truth. Of course, there are many situations in which the facts of the matter are disputed. Practically speaking, though, this is not the case with Polish involvement in the Holocaust. Although some people and the official apparatus of the Polish government continue to deny it, the scholarly opinion is generally that ethnic Poles participated in and committed tens or hundreds of thousands of murders of Jews.

One might also say that regulating speech is a far greater threat to discourse than lying, so we should not object to falsehoods. It is true that governments should not have the ability to suppress speech that they decide is false, but there is a difference between government censorship and a moral requirement for truth enforced by the people. (The French president, Emmanuel Macron, has suggested such a project to allow his government to decide what is fact and fiction in political reporting, and it embodies the central problems of government restrictions on speech in Western Europe.) If governments must be kept away from deciding what is true and false, the responsibility falls upon the people who are having debates. In this case, Professor George had a prime opportunity to set the record straight and return the Polish government’s debate over the Holocaust to the realm of reality. I think he should have seized the chance and made a stronger defense of truth in addition to free speech in his letter to the Polish prime minister.

Professor George has actually made a similar argument before about the importance of truth in debate. As he wrote last year in the opening line of a letter he published with Professor Cornel West, “the pursuit of knowledge and the maintenance of a free and democratic society require the cultivation and practice of the virtues of intellectual humility, openness of mind, and, above all, love of truth.” It is clear that Professor George supports truth as a value, but he might have done a better job fulfilling that value in this instance.