Among some members of Washington's political establishment, the last-minute remarks of departing presidential aide Peter Bourne about the use of "recreational drugs" by White House aides have created a kind of belated identity crisis.

"You know, it's hard to believe." said a former antiwar activist turned senator's aide, sitting before a coffee table holding the latest issue of the New Yorker, a formidable law dictionary and a small glass bottle of cocaine. "When they talk about official Wahsington using drugs, they're talking about people like me.

"It's really weird to wake up one day and realize that all of a sudden you are the 'them' that 'we' were always marching against."

It should have come, he said, as no surprise: "What did they expect? These are the people who have been smoking (marijuana) since the '60s. But you're not seeing a drug problem. We're not talking about people who are stoned out of their minds in the office or on pills 24 hours a day. These are people who know what they're doing, who know how to weigh the negative against the positive. These are people who read Consumer Reports."

Whatever the final fall-out from Dr. Peter Bourne's resignation as President Carter's health and drug control adviser, his departure has opened a window on a phenomenon largely ignored since marijuana stopped making headlines. Attention has suddenly been focused on the increasingly large part of the American population, especially in Washington, for whom the slogan "Better Living Through Chemistry" has been a double entendre for over a decade.

"The first time I smoked a joint it was a political statement," said one Justice Department lawyer, who, like most of those interviewed for this story, asked to be quoted anonymously for fear of jeopardizing their jobs or offending their friends. "It was the way you declared an allegiance to an ideology that was antiwar, antiestablishment, anti-all the things your parents were in favor of. Now, even my parents have tried it."

Now, there are car salesmen in Fairfax County who feel their sales performance is improved by the ephemeral self-confidence cocaine brings. Electronics experts in Marlow Heights contend that marijuana sharpens their concentration during the delicate but often boring business of wiring circuits. A former American University student recalls the Saturday night ritual of walking dormitory roommates up and down the halls to counter the effects of one Quaalude tablet too many; her own experience with drugs began with the Valium in her father's medicine cabinet.

Now, a Vietnam veteran can look back and explain how war can blast away any inhibitions a man might have about using drugs to chase fear and fatigue and, sometimes, any feeling at all. A recent addition to the job market talks of how marijuana coats the sense of alienation he feels in his new job, where all anyone seems to care about is passing the buck and protecting his own. And a source close to the Central Intelligence Agency contends that in the 1960s, if "the agency wanted to hire the best people they could find right out of college and turned them down for smoking grass now and then, they wouldn't have been able to hire anyone."

It is, of course, difficult to gauge accurately the prevalence of marijuana and cocaine use on Capitol Hill, inside the White House, or in the federal departments and their agencies. The experts and the statistics indicate that it would be more abnormal if there were not widespread familiarity with marijuana and a nodding acquaintance with cocaine among young professionals and bureaucrats.

But whatever the prevalence of marijuana's smoky haze and cocaine's fine white powder, "recreational" drug use exists in a sort of social shadow - considered commonplace in some the circles in Washington's geometry of power, politics and the press - and completely outlandish in others.

A senior journalist at this newspaper, for instance, compares cocaine to heroin. A colleague, 20 years his junior, compares it to coffee. For many of those caught up in the controversy over private use of illegal substances, it is a story of differences - between generations, between attitudes and perceptions, between Washington and the world beyond. It is a story, as well, of distance - and, in some very important ways, the lack of it - between some members of the press and the present occupants of the seats of power.

In part, said Robert Carr, senior consultant for the foundation-funded Drug Abuse Council, the recognition and the rumors of who is smoking what in and out of the halls of power are "simply an indication that you have crossed a generational line in government. A lot of the people working in this administration are young. Many of them are veterans of the civil rights movement, the antiwar movement. If they didn't smoke marijuana, they had a tolerance for those around them who did. They went to law school, they became professionals, they came to Washington. They weren't screaming, pillaging, shouting crazies. They were just normal people doing a job like everybody else."

"In the end," said Carr, "it becomes a question of values. There's no way to exclude them. Those who use marijuana and cocaine are practically indistinguishable from their nonusing peers."

Those who use marijuana and cocaine and work in the White House, however, have to contend with a new presidential edict that makes it clear that their business and pleasure are mutually exclusive.

"Everyone I know is taking this very seriously," said one young White House aide. "Everybody's talking about how you suddenly realize 'my God, you really do represent the White House.' When I go to Topeka, I'm the closest thing to the president most of them are going to see."

"I chose this life for myself," she said. "I knew this job would mean some changes. I wear dresses now and make-up, something I never did in the movement. I guess I can stop smoking grass in public too."

By in public, she means with "anyone I haven't known for five years." It does not mean that she will not smoke on weekends with her husband in their house in the suburbs or on week nights when there is a particularly difficult speech to think out. It just means that one has to be more careful.

On Capitol Hill, said the senator's aide who uses cocaine, there have been a number of little chats between administrative assistants to various congressmen and senators and their staffs. "They're very nice about it," he said. "They say, 'remember, what happened at the White House could happen here, so be careful.' I'll tell you one effect this is going to have," he said. "No one's going to be writing checks for their coke anymore. From now on, it's going to be strictly cash."

Whatever the financial arrangements, the official White House reaction and the splashy press coverage has shattered what had been, in many users eyes, a certain tacit approval of the discreet and private use of illegal and forbidden fruits.

"I think people were lulled into a false sense of security," said one agency official. "You'd hear all this gossip about how the FBI was turning up this information about regular marijuana use [in the course of routine job security clearance checks] and no one was being asked about it. It seemed as if there had been a decision to ignore it."

The fixed gaze in the other direction was buttressed, in many observers' eyes, by Carter's active campaign courting of rock and roll stars whose performances aided his fundraising efforts during the early days of his run for the presidency. His appearance at two picnics sponsored by Capricorn Records, where rock stars and their motley retinues openly smoked marijuana, seems now to some aides to stand in sharp contrast to the stern warnings recently handed down concerning the use of illegal drugs by White House aides.

The cascade of press coverage also seemed to some junior members of Washington's establishment to violate what one of them called "the Queensberry rules" that seemed to them to have been developed between the politicos and the press during the Carter campaign.

"There were only two unwritten rules on the campaign," said a former campaign worker transplanted now to the White House. "If you were married, you weren't supposed to (philander), and you didn't smoke grass with reporters. But, hell, that's where most of us got our grass."

There were a number of journalists attending the party thrown by the National Organization for the Reform of Marijuana Laws (NORML) last December where Dr. Bourne was alleged to have used cocaine. At least one reporter was a source for the front page allegations, while others say now that they do not consider the use of illegal drugs by a White House official a news story. "Unless it was proved to me that it had a demonstrable effect on the way he did his job," said one reporter who attended the party as a guest, "it's just not a story. It's their private life."

"I'll tell you one thing," said the proprietor of a trendy local restaurant, a man who occasionally finds himself privy to the secrets of men in high places and is now their self-appointed Cerberus, guarding them from the informational marketplace. "You won't be seeing many reporters at parties any more. Who can afford that kind of thing? You have a tank of nitrous [oxide] in the bedroom, two grams [of cocaine] in the living room and an ounce [of marijuana] in the kitchen - who's going to take any chances?

"Maybe," he added, "maybe it's all for the best. Maybe we all got too close."

It is, perhaps, indicative of the maze of issues raised by Bourne's departure that a number of people agreed to talk to this reporter because she has had experience with the very substances under discussion here. For the same reason, there were those who reacted with anger to queries by reporters with whom they were friendly. It seemed to them a betrayal of trust.

"How could you?" said one White House aide. "Its a different world outside Washington. They'll think that a bunch of wild-eyed freaks on acid are running the country. They'll say, 'No wonder the government's screwed up." It'll destroy credibility for our programs. They won't understand how hard we work."

"It's really too bad all this had to happen," said another reporter. "Sometimes, it seems like drugs are the only common ground everybody had left."

But it was a common ground with a tricky terrain, one which made the rules difficult to discern. While the camaraderie made it possible for NORML leader Keith Stroup to be invited to the White House and gave him an access impossible during the Nixon and Ford administrations, it also armed him with a certain amount of ammunition.

To some extent, it was merely coincidence that brought to light Stroup's six-month-old threat to publicize White House drug use if Bourne did not back down from what Stroup considered an attempt to oust him from NORML - an article in New Times magazine to that effect was on its way to the printer when the Bourne story broke.But the timing only heightened the sense of schizophrenia that many government officials, journalists and other interested parties were beginning to feel as the line between their personal lives and public responsibility became increasingly blurred.

Ironically, Peter Bourne's presence at NORML's sixth annual conference coincided with a crescendo in cocaine's popularity among Washington's young professionals, although some observers contend that this is merely another example of the city's eternal provincialism compared to the sophisticated seas of New York, San Francisco and Los Angeles.

Nevertheless, said one delegate to the NORML conference, it was indicative of the drug's increasing popularity that several large-scale cocaine dealers set up informal hospitality suites at the Hyatt Regency Hotel where tired participants could drop by for some quick refreshment. "I've never seen anything like it," said the delegate. "There's always been a little bit of coke around at the conferences, but never anything like this."

There is little wonder, said several observers, why cocaine would be so popular in certain circles. "It's the perfect workaholic drug," said a researcher at the National Institutes of health. "It doesn't slow you down, like marijuana. It lets you be ambitious with a buzz on."

And, he continued, "for a town that dwells so much on who's in and who's out, there's nothing like seeing whether or not you're invited into the bathroom for a toot to tell you whether you rate."

And to some, the obvious status appeal of the drug can be annoying. "I like doing the drug occasionally after hours," said one drug abuse expert. "But it gets a little, well, ostentatious when your colleagues invite you into their offices and make a big deal out of locking the door and drawing a couple of lines." It is, after all, only some people who can afford a status symbol that costs between $80 and $120 a gram.

For some of those who can afford to buy it regularly and in quantity, it is as much a concession to sound business sense as to the pleasure principle. "In my business," said one bar owner, "having good drugs around is a big asset. It puts you in with the avantgarde, social hip part of Washington. I think fully 75 per cent of the people who do coke do it because its chic. A lot of what's around is so watered down, there isn't enough coke to get high on.Me, I like it okay, but, personally, I prefer dinner for two at the Lion d'Or. It costs about the same and I find it more relaxing."