ARTS / As if Hitler never existed: The Deutsche Romantik festival has everything: music, art, literature . . . but there's a sinister omission.

How uplifting, how improving, how unimpeachably good for us it has all been made to sound. Deutsche Romantik on the South Bank is 'a major arts festival encompassing music, the visual arts, literature, film and performance, which celebrates one of Europe's great artistic movements and examines its continuing impact on the culture and identity of the German nation today'.

What on earth could possibly be wrong with that? Surely it is the South Bank's purpose to act as torchbearer for the bright flame of human creativity, wherever it has burned; surely, as Lord Weidenfeld suggests in his introduction to the catalogue of 'The Romantic Spirit in German Art 1790-1990', which opens next week at the Hayward Gallery, this is 'a project that is timely and relevant for all of us who wish to learn more about this interesting chapter in Europe's cultural history'. Surely we should hope, with the South Bank's Chief Executive, Nicholas Snowman, that 'the public will be surprised and startled, as well as entertained, as we enter the forest of German Romanticism'.

But the forest of German Romanticism is much, much darker than anyone at the South Bank Centre seems prepared to concede. All that anodyne, politely liberal language of cultural uplift - that talk of 'interesting chapters in history', of art's potential to shock (but only mildly), to 'surprise' or to 'startle' - seems, in these circumstances, almost comically misplaced. It is the language of concealment. The fact which almost everyone involved with Deutsche Romantik wants to avoid facing is that 'culture', especially a sense of 'national culture', can be a dangerous and even an atrocious thing. The most poisonous fruits of German Romanticism - Hitler, Nazism - demonstrate this with an appalling clarity.

Yet the links between Nazism and Romanticism are precisely what the South Bank's 'arts festival' (a term which itself suggests a rather simple-minded, lazily 'festive' attitude to the arts) assiduously seeks to suppress. Deutsche Romantik is sabotaged by its own timid reluctance to confront the single most fateful and momentous aspect of the history which it claims to be investigating - the way in which the literary and pictorial and musical ideals of the first Romantics would culminate, more than a century later, in the twisted, Volkisch, but none the less clearly Romantic notions of Hitler and his cronies.

The earliest German Romantics were fascinated by the notion of purification and developed a kind of metaphysics of destruction. Friedrich Schlegel, one of the first writers to use the term 'Romantic' in the modern sense, believed that 'only in the exhilaration of annihilation is the sense of divine creation revealed'. The same apocalyptic imagination can be sensed behind the paintings of Friedrich, who endlessly depicted the same confrontation between Man and Void, dreaming of a world purified almost to the point of abstraction; and behind the German Romantic exaltation of music as the perfect art form, pure because entirely without material aspect (music, as Schopenhauer remarked, can express everything except substance).

Now although it is possible simply to 'celebrate' such ideas and forms of art for their original, innocent purity of intention, it is certainly not very enlightening. This particular strain of Romanticism would mutate into one of the most virulent strains of Nazism - its evangelical, apocalyptic desire to 'purify' the world of unclean elements, to make it as actually 'clean' and 'German' a place as the mythical landscape into which Caspar David Friedrich's Wanderer gazes.

The great and troubling question which Deutsche Romantik begs - the great enigma of German history - is how such a mutation could occur. Part of the answer may lie in the fact that German Romanticism (unlike its left-leaning counterparts abroad) always contained the seeds of a violent and militant jingoism: Schlegel, and indeed most of his contemporaries, were deeply conservative patriots for whom a Romantic taste in art became just one expression of German nationalism.

But Deutsche Romantik chooses to treat such thorny issues in such a token, cursory manner that it might just as well have left them untouched. The Hayward exhibition, intended to chart the progress of 'the Romantic spirit' in German culture from its origins to the present day, treats the Nazis' special brand of Romanticism with a brevity that amounts to a confession of nervousness.

Likewise, the balance of the festival's programme of musical events declares (with considerable eccentricity) that Schumann was the archetypally Romantic German composer, when it was truly Wagner. Schumann was more of a romantic in the lower-case, sentimental sense, but Wagner was a Romantic in the upper-case, philosophical sense: the artist-as-god, creating and presiding over his own created world with a proud and absolutist imperiousness. The notion that Wagner was himself a proto-Nazi is a once-voguish cliche that has long since been seen through. But his aesthetic megalomania, the extremes to which he took the Romantic cult of free self- expression and the theatrical persuasiveness of his notion of the gesamtkunstwerk, the total work of art, uniting visual spectacle and music, light and the human voice - all these aspects of Wagner would, in ways that he could never have foreseen, exert a profound influence on Hitler's political beliefs and techniques.

Rather than trace such disturbing connections, however, Deutsche Romantik - like the Royal Academy's 1985 survey of German 20th-century art, which included no Nazi-approved art whatever - prefers a head-in-the-sand approach. There will be a 'Wagner Day' but, we are told, its 'chief excitement will be the first opportunity most of us ever will have had to hear four Wagner works on the instruments of the time'.

Most so-called 'arts festivals' on specific themes are merely opportunistic rag-bags. This is not to say (by any means) that this one's miscellany of German Romantic art, concerts, readings, films and all the rest is something to be avoided. But it is to say that Deutsche Romantik is thoroughly misconceived: it is actively constructed around a vast absence, an enormous hole of forgetting and historical distortion. Of course, as the organisers may care to argue in their defence, German Romanticism produced many, many things that were not Nazism - but Nazism was the biggest and most dreadful thing that it did produce. Any history which pretends otherwise is a lie.

Hitler was not some peripheral distorter of German Romantic ideas. He was, in many respects, their most extreme interpreter: the ultimate, because the maddest, of all the German Romantics. It is often said, because he dropped out of art school, that he was a failed artist who turned to politics, but Hitler was a monster precisely because he always remained, at heart, more of an artist than a politician. He managed to accomplish as much evil as he did because he brought, into the real political world, the megalomania and the purifying zeal of the artist as conceived by German Romanticism. Wagner dictated events absolutely within his theatre at Bayreuth; Hitler's theatre was Germany itself. Where Friedrich purified the world in paint, Hitler attempted to purify it in practice: the Final Solution was the appalling translation, into genetics, of that idealising strain within German Romantic aesthetics that dreamed of total purity. Where almost all the German Romantics dreamed of changing the world, Hitler went about the job of doing so - and not in the spirit of Machiavellian pragmatism that we associate with politicians, but in the radical Romantic artist's spirit of nutty but single-minded fanaticism.

The notion that pure evil might have anything to do with art runs directly counter to one of the most common but also most foolish modern beliefs - namely that artists and the arts are necessarily Good Things, that 'culture' is necessarily a positive force. This peculiar idea - Plato, who excluded artists from his ideal Republic, certainly did not share it - might be termed the fallacy of the therapeutic theory of art. If the troubled history of German Romanticism has a moral, it is that art is not always good for you. Perhaps Goethe, the most famous of all the German Romantics, should be allowed the last word on the subject. Romanticism, in his succinct definition, was 'sickness'.

Deutsche Romantik runs 29 Sept to 24 Nov. Details: 071-928 8800

(Photograph omitted)