June 26, 1992 | In the view of filmmaker Peter Cohen, writer and director of The Architecture of Doom, the terrible phenomenon of Adolf Hitler and his Nazi nightmare must be understood in aesthetic, rather than political, terms. Through his engrossing documentary, Cohen persuasively argues that Hitler's zealously vicious campaign to ''purify the race'' was a natural extension of his desire for purity of art.

Hitler, described by narrator Bruno Ganz as ''a failed painter who dreamed of being an artist,'' comes across here as a sentimental madman obsessed with, and informed by, the grandiose mysticism of Wagner, the adventure-story hokum of novelist Karl May, and the middle-brow banalities of ostentatious kitsch.

Under his absolute control in Nazi Germany, modern art was reviled as ''degenerate,'' the avant-garde condemned as ''Bolshevik un-art and un-culture.'' Only the most romanticized renditions of racially pure and beautiful Aryans had any place of honor in the state-approved art museums.

The Architecture of Doom consists almost entirely of archival footage, newsreels and period photographs. And some of the most unsettling of its many unsettling images depict how Nazi-approved art experts used slide-show displays to note similarities between the faces of the deformed or insane with the images in modernistic portraits. That was their ''proof'' of the twisted, degenerate nature of modern art.

In the Nazi Germany that Cohen has re-created in his film, aesthetics equals morality equals state policy. Hitler wants to purge his beloved fatherland of the mentally deficient and the physically deformed, much the same way he seeks to rid his country's museums of bad art. He wants to create a new mythology of Wagneresque supermen -- and personally designs the Nazi insignia and uniforms. Along with Albert Speer, he designs monstrously immense buildings and stadiums as self-aggrandizing memorials. And in doing so, Hitler adheres to what Ganz describes as the Fuhrer's ''ruins principle'' -- the buildings are designed so that, after thousands of years, they will look every bit as impressive and immortal as the classical ruins of Athens and Rome.

The Jews? In Hitler's mind, anti-Semitism is not merely aesthetic, it is hygienic. Time and again in Nazi propaganda -- most notoriously, in the 1940 film The Eternal Jew -- Jews are vermin, lice, inhuman pestilence that threaten the health, well-being and racial purity of the good German people. Little wonder, then, that when the time comes to implement the Final Solution at Auschwitz, the mass murderers use an insecticide, Zyklon B, to annihilate their prisoners.

Thus, in the twisted minds of the instigators, the Holocaust is not a crime against humanity -- it is simply good housekeeping.

The Architecture of Doom is a provocative rethinking of the unthinkable, a fresh and fascinating attempt to comprehend the incomprehensible.