Quite simply, Chicago is the architectural capital of the world. It is here that the great architects - Louis Sullivan, Frank Lloyd Wright, D. H. Burnham, Mies van der Rohe, and many others - left their mark on the city's skyline. Many of their structures are still standing: the Reliance Building, the Monadnock, the Tribune Tower, and many of Wright's houses.
New York may have more architectural specimens, says architect Wilbert R. Hasbrouck, but they are not as visible nor as geographically concentrated as in downtown Chicago.
If this city has been the leader in times past, where is it going in the future? There are many answers.
''Nowhere,'' says Carl W. Condit, professor emeritus of art history and urban affairs at Northwestern University. ''I have the feeling architects are really unsure of themselves. It's a faceless kind of architecture with odd shapes.''
''Poppycock,'' responds Bruce Graham, a partner with Skidmore, Owings & Merrill. The same criticisms were made of Sullivan and van der Rohe in their day. Chicago will remain a leader in architecture precisely because it pays little attention to critics or ephemeral fashions, he says. Rather, good architecture is a continuum of innovations backed by what Mr. Graham calls ''structural sanity.'' For example, architects are paying increased attention to the use of space, he says.
There is also more concern about interior detail, a sense of human scale, and variety, adds C. William Brubaker, executive vice-president of Perkins & Will.
Meanwhile, says Mr. Hasbrouck, old buildings are being restored as never before - partly because of favorable tax credits since 1981. His firm has been involved with more than 20 major projects in Chicago and is currently restoring the famous Rookery and the Reliance.
Another catalyst for innovation will likely be the run-up to the world's fair to be held here in 1992, says Kim Goluska, an associate with Skidmore. The famous Chicago world's fair in 1893 helped spur innovative building in a decade known as one of the most creative in architectural history.