Walter Gropius's Bauhaus, a school and dormitory complex built in Dessau, Germany, in 1925-26, is one of the great paradigms of modernist building - and it says a lot about the culture of its time. With its sheets of unadorned glass and metal and its abstract geometry of cubic forms, it meant to impose an image of revolutionary authority by erasing all reference to previous historical styles. Ironically, however, this process of historical erasure (known as the international style) created a new symptom of authority's decay. It allowed no reference to the ancient sense of habitat, to a regional center, to a sense of the dwelling as a part of human origin. Because this architecture's facade was indifferent to its surroundings, it could and was meant to be used anywhere, everywhere. It was truly placeless.
Postmodernism revolts against modernist architecture's anti-historicism. ''In a certain sense,'' as Paolo Portoghesi writes in ''Postmodern: The Architecture of the Postindustrial Society'' (New York, Rizzoli International Publications, 156 pp., $25 paperback), ''these are the years of 'refound time.' '' How different the austere forms of Gropius's Bauhaus are from Philip Johnson's new, towering AT&T building in New York. The latter building is lush with historical allusions - seen in its great covered plaza, its huge semicircular arch, its row of columns running across the structure's upper stories, and its notorious pediment, which rejects the flat top of modernist skyscrapers for a form that looks more like a Chippendale highboy than anything else.
Johnson, who was once a major practitioner of the international style, joins such colleagues as Michael Graves, Charles Moore, and Robert A. M. Stern as a spokesman for this architecture that combines historical styles in a single facade - a multiplicitous image of pastiche, an eclecticism that we have come to know as the significant practice of postmodern production. But the practice of pastiche converts historical distinctions into a series of equivocal mannerisms that, by denying historical difference, manifests modernism's latent fear of decentered authority and celebrates a kind of mimicry: the collage of copies, the distance from origins, the play of historical surfaces.
Postmodern architecture's ''refound time'' suggests how utterly removed from unified authority our society has become. For historical eclecticism actually reveals an inability to locate ourselves historically. Moreover, this failure discovers a historical moment of its own, perhaps the first truly decentered historical epoch, advertising its sense of multiplicity - our epoch of ambivalence.
I am interested particularly in the postmodern facade, though the interiors of these buildings enforce the same eclecticism. The facade is in fact a tableau very much akin to Twyla Tharp's dances in the visual culture of our time.
Here is the will to consume every possible image and, in turn, to display it. Here the cornucopia of the image flows out in a triumph of re-presentation that controls the rage of information, not by restricting its quantity but by diluting its quality, by distancing us.
Like the video monitor and the television screen, the facades of pastiche are all about reproductions that replace originals, about images that reassemble quotations from reality for their instantaneous effects and dispersal. All information is reduced - that is, freed from its historical complexity - without offering an alternative center of authority. It is free, at last, to reach an ecstasy of amnesia, to become a commodity consumed and tossed away because it's merely a surface floating past - a past that has lost its depth and weight.
This is the extraordinary paradox of the postmodern building: Its imagery does not float away. It is here before us, monumentally solid. Portoghesi's international anthology illustrates the works of postmodern architects in lavish detail. His lengthy polemical essay argues, not surprisingly, for a society with many centers - a polycentric society populated by the buildings of pastiche.
There can be no totalitarianism, he asserts, in such a world. But we must now ask if his ''refound time,'' his decentered or polycentric imagery, is not finally a collapse of historical understanding and to what effect? To live in these buildings, to work in them, to grow up in their sight (site) - have we abnegated the past by displaying it as a pastiched surface, as a commodity?
And what then of the crisis of authority? Our notions of authority may well have to change, but where does postmodern architecture leave us? The placelessness of the international style hasn't finally been replaced. It has only been transferred to the facades of these new buildings, which are covered with the collage of historical ambivalence, of historical placelessness.
This new placelessness looms.