From Disneyland to Byzantium, that's the way author Jerzy Kosinski sees Washington. Once "poor and innocent," it's now, he says, a town "obsessed by betrayal, by the usurpation of power, by camouflage, the corruption of the spirit."

He loves it.

He said so this weekend, after a champagne toast in a Georgetown dining room, and again yesterday, over coddled eggs in his suite at the Four Seasons Hotel. By the window was a single peach rose; a rose that faced a town still asleep.

"What I meant," he continues, "is that finally, Washington caught up. Byzantine is not awful -- it's great. I think it becomes very exciting. Washington, in the last years, became far closer to the nature of my fiction." w

Which is fiction of war, of death, of torture. In "The Painted Bird," published in 1966, a peasant pries the eyes of another out with a spoon, then stomps them under his boot. In a series of essays on "Steps," a novel that won the National Book Award, Kosinski writes that hell "is the inability to escape from others who prove and prove again that you are as they see you."

Yesterday, above Pennsylvania Avenue, he seemed spry. The day was sharp and sunny and Kosinski's hell, for the moment, had vaporized with the steam from the streets.

"I used to come here often, and you expected to meet Disney characters. I'm not kidding. Senators looking so incredibly pure."

Not these days.

He's asked about the eight congressmen reportedly linked over the weekend to an FBI bribery probe. "Of course it's deplorable," he says. "But at the same time, power corrupts. Why should Washington be excluded from folly? Maybe if you don't take the money now and run, it will be gone in three weeks."

Byzantium, that splendid and devious Mediterranean empire, is now set aside with the coffee and croissants. The time has come for Kosinski to speak, frenetically, about his reason for making the trip down from New York. And about the reason for the toast from Sen. Claiborne Pell (D-R.I.), and the reason for the dinner from Washington hostess Ina Ginsburg. And the reason for the Sunday lunch, this one from Polly Kraft, and the reason for the cocktail reception and the dancing and the . . .

The commotion is all for last night's Washington premiere of "Being There," a movie based on Kosinski's novel about an attractive simpleton who does nothing but garden and watch television. In the beginning, he's transfixed by game shows, among others. By page 116, in the paperback version, he's still transfixed by game shows but is also being suggested for vice president. That's vice president of the United States.

"I don't abhor television," says Kosinski. "My issue is with those who watch it. Seven hours a day -- that's half of our waking time. Now what do we watch? We say we watch reality. But what is reality? We watch a box, at home."

A knock on the door. Reality comes in the form of a photographer with a Nikon around his neck, something that sends Kosinki immediately to a mirror.

He combs the wiry, black hair, regards the aquiline nose, checks the striped button-down with the embroidered "JK" on its breast. Kiki von Frauhofer, cosmetics marketing expert and European baroness who has lived with him for 15 years, once said he looks like a camel. Or a seagull.

He sits obediently for the picture, and after awhile doesn't notice the camera clicks. That's because he has begun afresh on Washington, a town, he says, with superb elements of unsanity.

Not sanity or insanity, but a state that is neither nor. The character of Chauncey Gardiner, television watcher in "Being There," is unsane, as determined by the Journal of the American Medical Association. The doctors called it "the line of demarcation between mental health and mental illness." Kosinski calls it Washington.

"Watergate, for instance, would quality as unsane. There are a lot of things there that a normal person wouldn't do -- like recording yourself.

"And the public tragedy of Martha Mitchell, at the time, struck me as unsane. This quoting her all the time. The woman was not well."

But then again, unsanity certainly keeps the blood flowing. "There is the unpredictability of encounter, of intrigue," he says. "It creates a high degree of social voltage. You have figures of drama here." At this point, the name of Treasury Secretary G. William Miller comes up, along with a reference to allegations that Miller, while chairman of Textron Inc., was aware of an improper $600,000 entertainment fund.

"I mean $600,000 for entertainment," says Kosinski, and he laughts with great relish. "You can see the belly dancers -- right?"

Not last night, you couldn't. At least not at Desiree, the Four Seasons nightclub where everyone collected for the after-premiere supper.

Nonetheless, there were more than a few Byzantine elements: an incredible buffet that even those veterans of incredible buffets marveled at, flashing neon lights for dancing, and lots of Washington characters who talked about the latest Washington intrigue -- the FBI "sting" operation and the eight congressmen.

And don't forget the hugh trays of jumbo shrimp that were carted out regularly and dumped into bowls filled with ice. Some people even grabbed for them mid-route.

Among the guests at the premiere and supper, which benefited the American Film Institute, were Jean Firstenberg, new director of AFI; George Stevens, AFI board chairman; Rep. John Brademas (D-Ind.); columnist Jack Anderson; Gerald Rafshoon and Gretchen Posten of the White House, and the usual crop of socialites.

Kosinski held court near the bar, signing autographs and at times even getting into apparent intellectual discussions with fans. This is unusual at Washington parties.

"This is my reward, my bribe," he said, gesturing toward the dim room filled with black tuxedos and thin, elegant women. "I live in a 1 1/2 room apartment in New York. You think I ride in a big limousine when I travel alone?"