One of Adolf Hitler's ambitions was to create the greatest museum in the world. He established this museum in Linz, capital of the upper Austrian region where he was born; and in 1941 he told his retinue that the Linz gallery could now hold its own with the leading American galleries.
But such a gallery would have need of masterworks, and to obtain them Hitler systematically plundered museums in all parts of Europe. He began by taking over the works by Viennese Jews. In 1945 entire lists were found - lists of stolen items destined for the Linz museum.
At the close of the war an Italian, Rodolfo Siviero, went to Germany and successfully negotiated - over a difficult 30-year period - for the return of the masterpieces stolen from Italy. These works - some signed by Leonardo, Memling,
Rubens, Veronese, Tintoretto, Canaletto - are now on view at the Palazzo Vecchio here in Florence.
And in this display are also to be found some watercolors by Hitler, which serve as a kind of footnote: ''Those who can, do; those who can't, steal.''
Hitler fancied himself a Renaissance man. And whenever he touched upon the arts - especially the arts of painting and architecture - he was convinced that his genius would set the standard for the German people and the Third Reich, that his word would always be the last word, simply because it was the right word.
When seven of Hitler's watercolors were published in 1936, an announcement of this event in the ''Volkischer Beobachter'' affirmed that the German state had taken on, in the most natural way, an artistic form under Hitler'sdirection - a man who is ''an artist, the architect and the builder of the national-socialist state.''
The account continues: ''Today we know that it was not by chance that Adolf Hitler was not to be found among the many students enrolled in Vienna's Academy of Painting. He was destined to fulfill a higher role than that of a good painter or a good architect . . .. There exists an intimate and an unchallengeable link between the artistic works of the Fuhrer and his political Grand Opera. His artistry is also at the root of his development as a politician and as a statesman.''
While it was true that the Fuhrer's followers were prone to make and to accept such inflated pronouncements, the cold glare of hindsight reveals that Hitler was little more than a Sunday dilettante. An earlier critical estimate, in fact, called him a truculent dilettante; but Sergio Salvi, director of Florence's Center of Exhibitions, writes that ''Hitler wasn't totally a Sunday dilettante, but a little professional painter who worked from Monday through Saturday; his watercolors demonstrate that as a painter he could in no way be thought of as a truculent.'' His approach was ingenuous, sentimental, the work of an Austrian provincial who stood in admiration of the elegant cities of Vienna and Munich.
Hitler was no easel painter. His watercolors give the impression that he worked from post cards; and, as Salvi again observes, ''he copied them too well - hence badly.''
As an artist, Hitler's taste and ability never rose above the level of a decadent romanticism. The 20 paintings now on view at the Palazzo Vecchio in Florence reveal his interest in grand architecture, his preoccupation with realistic detail, and his total inability to depict the human figure with any sense of grace equal to the palaces.
Furthermore, his people are stilted, often awkward, and faulty in perspective.
Although this period of his production terminated in 1914, his immature notions of what constitutes great art were later, in the 1930s, to shape a Nazi orientation that emphasized the traditional, noncontroversial values of heroism, work, production - a kind of photographic neo-classicism that railed against the futurists, the cubists, and especially the dadaists.
In his autobiography, ''Mein Kampf,'' Hitler shot a blast at contemporary art. ''Sixty years ago,'' he wrote, ''an exposition of the so-called dadaistic 'experiences' would have been simply impossible, and the organizers would have been consigned to insane asylums.'' He then went on to say that the day was coming when this scandal would be over, for ''it is the duty of the state's government to prevent a people from being thrown into the arms of spiritual folly.''