Symbolist art thus strove to represent something other than self-evident physical reality. It was romantic up to a point; it was often allegorical; it was dream-like or fantastic when it wished, and it occasionally reached into those remote areas delineated by Freud in his exploration of the unconscious. Its antecedents may be sought among figures such as Fuseli, Goya or William Blake. But the roots of Symbolism are also to be sought in the fertile soil of Romanticism - the Romanticism of Novalis, E.T.A. Hoffman and Jean Paul rather than Alfred de Musset or Victor Hugo. The solipsistic stance so central to Symbolist art is to some extent prefigured in Romanticism. The movements are nevertheless distinct. Rooted in the Protestant mentality of Germany, Romanticism implied a fervent, mystical bond with Nature seen as the created word of God.

  Symbolism, on the other hand, born of the Catholic mentality of France, Belgium, Austria and parts of Germany, no longer showed the same veneration for nature. "Nature, as he [des Esseintes] used to say, had had her day; the disgraceful uniformity of her landscapes and skies had finally worn out the patient appreciation of the refined. In the last analysis, how platitudinous she is, like a specialist confined to a particular domain; how petty-minded, like a shopkeeper stocking one article to the exclusion of any other; what a monotonous storehouse of meadows and trees, what a banal purveyor of seas and mountains! Besides, there is not a single one of her supposedly subtle and grandiose inventions that it is beyond the means of human genius to create; no Fontainebleau forest, no moonlight that cannot be reproduced by a decor bathed in electric lighting; no waterfall that hydraulic engineering cannot imitate to perfection; no rock that papier-mache cannot counterfeit; no flower that fine taffeta and delicately coloured paper cannot match! No doubt about it, this sempiternal chatterbox has by now wearied the indulgent admiration of all true artists, and the time has surely come for artifice to take her place whenever possible."

  These words were given to his idiosyncratic brainchild by Joris-Karl Huysmans in 1893, almost exactly a century ago. In Against Nature, the caustic art critic and brilliant novelist enshrined some of the more striking features of Symbolist art. No longer was nature to be studied in the attempt to decipher its divine message. Instead, the artist sought subjects uncanny enough to emancipate imagination from the familiar world and give a voice to neurosis, a form to anxiety, a face, unsettling as it might be, to the profoundest dreams. And not the dreams of an individual, but of the community as a whole, the dreams of a culture whose structure was riddled with subterranean fissures. The whispering collapses distantly audible throughout the edifice offered a discreet foretaste of the world's end. "Decadence" was the great issue of the Symbolist age, "decadence" the term that des Esseintes chose to characterize it.

  Decadence meant the rejection of "progress" as a misunderstanding of the true nature of things. Everyone else was climbing onto the bandwagon of progress; the decadent chose to stay behind. Turning in on himself, he rejected the exoteric culture of science and sought consolation in esoteric pursuits. It was the combination of this attitude with the dictates of fashion that made the dandy the Symbolist figure par excellence: the "prince of an imaginary realm" in Disraeli's words. And it was the need for a purely imaginary superiority that lay behind the somewhat hysterical arrogance of that supreme dandy, Count Robert de Montesquiou. Montesquiou was the model for both the comical figure of des Esseintes and the tragic Baron de Charlus in Proust's Remembrance of Things Past.

  We are thus faced with an insoluble paradox. For in "normal" times - in periods of lower social tension - far from being the secret garden of a few privileged souls, the underlying Symbolism of culture, which these lonely figures were so eager to preserve, constituted the common ground on which the cohesion of society as a whole was built.

  Art, from the very outset, had been laden with symbols. Only quite recently, as a result of a notorious misunderstanding of the Renaissance ideal of "imitation of nature", had it been assumed that it was the artist's business scrupulously to reproduce what he saw. Yet, if art is to hold our interest it must refer to something over and beyond itself and its manifest subject. At its best, even Impressionism captures a part of daily reality as elusive as the metaphysical: the fleeting moment of immediate experience. Impressionism is thus a kind of borderline case, contriving to be compatible with an age which, under the sway of Positivism, rejected as unreal that which could not be touched and measured.

  The high-strung idealism of so much Symbolist art led to its rejection in later years. The First World War was a devastating exposé of contemporary illusions, and in works such as Celine's Journey to the End of the Night a despairing conclusion was drawn. Almost at the same time came Freud's revelation of the hidden roots that sustained a certain kind of idealism: sublimation. Similarly, the critical apparatus elaborated by Marx and widely accepted by historians and thinkers has allowed us to comprehend how ideology uses mythopoeic representations to consecrate the existing hierarchy of power.

  It is easy enough to see why the naive complacency of much Symbolist art laid it open to criticism. But time has passed, ideas have changed, and we are now in a position to take a fresh view. The anthropologists of this century have shown how the symbolic foundation of culture is indispensable to the well-being of individuals and to the survival of society. It alone can signify values worth serving and provide each member of society with a clear perception of his or her individual and sexual identity. Such things are not within the purview of reason, but arise out of a preverbal, symbolic order which reason cannot afford to ignore. Nor has Symbolism ceased to exist. It remains active today in the work of poets and dramatists; an attentive ear will discover vestiges of it even in the essentially modern plays of Samuel Beckett. It is also spectacularly present in the cinema, in the baroque splendours of Fellini and Pasolini.

  Indeed, irony was never incompatible with Symbolism. Academic and sentimental works predominate, but French Symbolist poetry numbers amongst its exponents not merely Jules Laforgue, whom we have cited, but Alfred Jarry. Jarry's dandyism and whimsicality make him very much a Symbolist; in his oeuvre, we encounter a transition to the modernism of Duchamp.

  It was in fact among Symbolist artists that a notion of the absolute autonomy of art first appeared. The assertion had a particular resonance in a society which by and large expected art to be "edifying". Modernism took up this doctrine and required that art, like mathematics, be recognized as a separate realm, unrelated to the context in which it appeared. In several respects, then, a real continuity can be seen to exist between the art of that age and our own. If we fail to perceive this, it may be because we believe that Modernism marked a radical and definitive break with the past. But this is yet another myth: the founding myth of Modernism itself.