What does the cinema know that we don’t? What can it tell us about ourselves, our society?

Rüdiger Suchsland’s new film, “Hitler’s Hollywood – German Cinema in the Age of Propaganda: 1933-1945,” which opens April 11, asks these questions several times in differing forms. Indeed, one might truthfully say that the film exists for the express of purpose of asking these questions and to offer some tentative answers.

Suchsland’s previous film, “From Caligari to Hitler” (2014), took its title from the book by Siegfried Kracauer and used the Frankfurt School theoretician’s model as the framework for exploring the trajectory of Weimar cinema as it meandered its way from Expressionism to the Nazi inferno. The new film plunges headlong into the flames. After a giddy if unlikely musical duet between Sherlock Holmes and Dr. Watson (universally loved characters who can be found in a dizzying array of national cinemas, including that of the Third Reich), Suchsland steers us through some handsome color footage of the German bourgeoisie at play, noting dryly that “most Germans had adjusted themselves to the regime,” adding that “cinema offered an additional distraction” from the National Socialists sweeping away of political dissent, social outcasts and, especially, German Jews.

As Suchsland, himself a film critic and theorist by training, makes abundantly clear, the Nazi leadership was intoxicated by the power of cinema. They quickly consolidated their hold on the film industry, shutting down all production companies but UFA, which was taken over by Joseph Goebbels and the Ministry of Propaganda. From now on, German film would speak with one voice, in the unmistakable accent of Nazism.

The result, as the film attests with its generous choice of excerpts, was a remarkable uniformity of message, cutting across genre lines regardless of the frivolousness or gravity of subject matter. Pure propaganda films were relatively rare, but films that questioned the ruling ideology were even fewer, and the number of filmmakers who dared challenge the assumptions on which the Third Reich was founded numbered not even a handful.

As the film’s narration (read by actor Udo Kier with a nicely ironic tone) points out, Nazi cinema was not a cinema d’auteurs. The great German directors had been driven out as Jews (Ophuls) or had escaped as anti-Fascist refugees (Lang). The only significant exception was G.W. Pabst, who had barely missed out on emigration to the U.S. or France; as the extended clip from his weirdly haunted 1943 film “Paracelsus” indicates, he was one of the rare voices of condemnation, albeit heavily allegorized, challenging the murderous mystifications of Nazi ideology.

The remainder offered a dreamlike reverie haunted by the specter of impending death. Suchsland argues forcefully that the logical end of all the oneiric maunderings of Nazi cinema was “a mythical yearning for death.” Fixated on the Wagnerian (and pre-Wagnerian) obsession with “Liebestod” and “Götterdamerung,” German films of the period were drenched in a suicidal urge that could be read (sometimes with difficulty) as an omen of the downfall to come.

If that is what this cinema knew, it isn’t always clear that it could communicate that knowledge to the seemingly satisfied customers. Despite Suchsland’s copious use of clips from the films, it isn’t always apparent that the absurdly cheery musicals with their gauche, pseudo-jaunty-American songs are paving the way to Stalingrad and the Reichsbunker. Despite marshalling such exemplary explicators as Kracauer, Susan Sontag and Hannah Arendt, Suchsland is frequently left holding a bag whose uncertain contents may or may not conform to his overarching theory.

Part of the problem lies in his decision to treat the entire subject in a more or less strict chronology. As a result, he leaps awkwardly from films and filmmakers whose work supports his ideas — notable the odious Veit Harlan, of “Jew Süss” infamy — to films that seem to undercut it. Too often, “Hitler’s Hollywood” feels like the work of someone who has fallen madly in love with his research, who cannot bear to omit an interesting fact or an evocative film clip. As a result, we get such engaging digressions as a look at Ingrid Bergman’s one German film, a strange quasi-feminist item that ends, as such films always did under Dr. Goebbels supervision, with her dropping career for marriage. Elsewhere, Suchsland detours into the work of Helmut Kaütner, a younger filmmaker whose career would extend from the war into the late 1970s with convincing anti-Nazi credentials.

Nazi cinema existed in an irony-free zone in which an anti-British item like “Ohm Kruger” could earnestly denounce anti-Boer imperialism for its use of concentration camps and the wholesale genocidal butchering of civilian populations. On these blatantly propagandistic efforts, Suchsland is appropriately tough and smart, but these aren’t exactly hard targets to hit. It’s much more difficult to decide what the cinema knows when the messages are shrouded in bonhomie or melodramatic intimacies and here Suchsland is a bit more unsteady. As a result, while “Hitler’s Hollywood” is fascinating for its revelations of a relatively unknown cache of some thousand feature films, its message, though commendable, is a bit blurry.

Rüdiger Suchsland’s new film, “Hitler’s Hollywood – German Cinema in the Age of Propaganda: 1933-1945,” opens April 11 through April 17 at Film Forum (209 W. Houston St.; [212] 727-8110). For more information, go to filmforum.org.