Victor Klemperer, a professor of Romance languages at Dresden University and one of the few Jews to live in Germany for the duration of the Nazi regime, knew well the power of words.

From 1933 to 1945, Klemperer kept a diary in which he recorded the agonizing details of everyday life under a dictatorship, alongside his analyses of Nazi propaganda.

That invaluable account, along with his 1947 book, LTI: Lingua Tertii Imperii” (“The Language of the Third Reich”), provide the text and inspiration for “Language Does Not Lie,” a fascinating and unusually complex documentary about the Third Reich and the Holocaust.

“Language Does Not Lie” has its U.S. television premiere at 9 p.m. Monday, Oct. 23 on the Sundance Channel.

Czech-born, French-based director Stan Neumann transposes Klemperer’s words and insights to film with a rare blend of austerity, lyricism and intellectual depth. He employs black-and-white recreations and rare archival footage to illustrate the period, using very little music or ambient sound as a sweetener. Klemperer’s diary entries (read in English) provide much of the soundtrack, accompanied by the thwack of typewriter keys — until the day when Jews are prohibited from owning machines, and the professor has to revert to a fountain pen.

“Language Does Not Lie” is an infinitely more restrained and subtle Holocaust film than we are accustomed to. However, its intellectual underpinnings notwithstanding, it never forgets that words have consequences, and that the words of the Nazis led directly to the deaths of millions.

“They broke all their promises, except those they made to the Jews,” states an actor who appears from time to time to recite a whispered joke or song that comprised the gallows humor of the day.

Klemperer’s wife wasn’t Jewish, which explains why the professor wasn’t deported to Auschwitz. But they certainly suffered, especially after he was expelled from the university in 1935. His diary became increasingly important, for it gave structure and purpose to his days, and served as a project for his analytical mind and a means of preserving his dignity.

The Nazis’ calculated use of archaic and invented words for propaganda purposes was Klemperer’s favorite subject. Viewers less inclined to academic commentary will find greater resonance in the evolution of Jewish persecution, as carefully delineated in his diary.

One shocking detail is that substitutes were listed for every transport. The ever-diligent Gestapo had learned to anticipate a certain number of suicides by Jews who had a sense of what lay in store, and took care to make sure those “openings” were filled by others.

From another standpoint, “Language Does Not Lie” can be seen as a kind of a dialogue between Klemperer and Joseph Goebbels, Hitler’s minister of propaganda. The film is peppered with Goebbels’ impassioned and deviously structured speeches, which sound even more maniacal in contrast to the clinical tone of Klemperer’s analysis.

Although Klemperer and his wife survived the war, the film does not have a happy ending, strictly speaking. After all, 6 million Jews were killed by Hitler’s henchmen. Yet without striving for a comfortable or uplifting resolution, “Language Does Not Lie” reminds us that one person at the right time and place can make an immeasurable difference.

Klemperer’s diary, and by extension the film, is a testament to the power of bearing witness. Initially, the title “Language Does Not Lie” seems to refer to the Nazis’ unambiguous plans to destroy the Jewish population of Europe. By the end, we realize that it refers to Klemperer’s writings, which are a permanent record of the Nazis’ crimes.

After Klemperer’s death in 1960, his wife donated the diary to a Dresden archive. It was subsequently discovered and edited by a former pupil, and published in Germany in 1995. Three years later, the first volume, “I Will Bear Witness: A Diary of the Nazi Years, 1933-1941,” was released in the United States to unanimous acclaim.

“Language Does Not Lie” airs 9 p.m. Monday, Oct. 23 and 9:30 a.m. Friday, Oct. 27 on the Sundance Channel.