Hey Dallas, get down and dirty!

Muss up your sidewalks. Clutter up those city plazas and parks. Take the big plunge: risk a few public benches. If a bag lady winds up sleeping on them, well, bubba, western civilization is still going to be here in the morning.

Don't get frazzled if a kid drops a hot dog wrapper on City Hall Plaza.

Lighten up on jaywalkers.

And while we're at it: how about some retailing downtown? How about some housing downtown? How about a real downtown?

The eminent city doctor, urbanologist William H. Whyte, has paid a house call here. He has been studying Dallas for seven years the way he studies all cities: clicking his people-counter at busy intersections; measuring the width of sidewalks, length of park benchs and height of building ledges; observing the ambulatory patterns of window-shoppers, office workers and city schmoozers.

His prescription, delivered in lectures at the Dallas Public Library this week, amounted to an impassioned plea to what is almost indisputably America's tidiest, uptightest, most self-conscious, most aspiring, most adolescent (in the sense that it is still figuring out what kind of city to be), most Calvinistic big city: let your hair down.

Whyte, a Pennsylvanian and New Yorker whose books include "The Organization Man" and "The Social Life of Small Urban Places," was warmly received by audiences of 200 or so on separate nights, and that in itself was taken by some as a measure of the city's progress.

"Dallas is ready to broaden its notions of what constitutes a downtown," said civic leader Gail Thomas, who helped organize the lectures. "Six years ago, Dallas wasn't ready to think about park benches, because it was afraid the races might have to sit together. That's changed."

Still, if downtown Dallas is to grasp Whyte's ideal -- to become a bustling, congested, lively, people place -- it will need a long reach. Like so many Sun Belt cities whose explosive growth came after suburban malls were well established, it is inhabited by office workers accustomed to a soulless, business-only, 9-to-5 downtown.

In preparation for his lectures, Whyte distributed questionnaires about the city, and the answers were revealing. Asked to identify the "center" of Dallas, fewer than one-third of 560 respondents named any downtown location. One-tenth said the city's center was on one freeway or another. The response from 44 was, in effect, "What center?" Six said it was North Park Mall -- which isn't even the best mall in town.

The respondents said in overwhelming numbers that they would like to see housing and retailing downtown. But there's something funny here: those in the know say there's no housing downtown because "the numbers don't work" -- meaning that no developer will risk it -- as if the "numbers" had nothing to do with lack of demand.

The respondents identified Thanksgiving Square, a one block mini-park in the middle of downtown, as their favorite outdoor spot. The park's gates are locked at 5 p.m. each day for insurance reasons, and a developer has just put up a new skyscraper across the street that blocks the park's sun for a few crucial hours each afternoon.

"I must say, you're too easy on your developers here," chided Whyte, who last year recommended that one of Dallas' huge, sleek, monumental -- but on the whole inhospitable -- public places, the concrete plaza of architect I.M. Pei's City Hall building, be warmed up with outdoor pavilions and food kiosks.

Nothing doing. "The reaction was, 'We don't want to profane this sacred place,' " he said.

Whyte said that even though progress is being made, he is amazed at the scarcity of places to sit downtown, a lack he attributed to the Southwest's outsized fear of "undesirables," or street people.

He said he thought that undesirables, like vendors or newspaper stands or anything else that clutters up downtown, were, in fact, desirable. This drew a lecture from a man in the audience who said street people were "also God's creatures . . . . We shouldn't talk about them like they are street furniture." His point missed, Whyte did not respond.

There are other explanations for Dallas's benchlessness. "A lot of people in Dallas think you can't sit, because sitting means you're not working," said Bill Marvel, architecture critic for the Dallas Times Herald, who recalled being shooed off a seat-height downtown building ledge by a security guard.

But attitudes may be changing. Skyscraper developers in Dallas have begun to include plazas in their "amenities packages." They have decided that it is good business, just as the city fathers have decided that building a downtown arts district is good business. This is a city that wants to be taken seriously, wants to be big league and, if art and plazas are the ticket, it will pay.

"I'll do anything you want to help the Dallas Symphony," is the famous quote from ex-mayor and civic booster R.L. Thornton, "Just don't make me go."

Say this for Dallas: when it gets a notion, there's no stopping it. Ten years ago it built the world's biggest airport, five years ago it started to latch onto the arts. Next, who knows, a little funkiness?

"I can see it now," said Whyte, who expresses admiration for the city's vitality. "They'll get together a Department of Funk, and they'll . . . . "