Attorney General William French Smith is under public fire for the first time in his life. Until his move to Washington last year, his had been a refined, aristocratic life spent in corporate board rooms and private clubs.

He is trying to deal with the new situation, open warfare on a public servant, philosophically, and quotes Harry Truman: "If you can't stand the heat, get out of the kitchen." Confronted with criticism of his private finances and professional competence, he says that he has done nothing improper and sniping from the White House, Capitol Hill and special interest groups "comes with the territory."

But people around him say he is hurt, angry and confused about the onslaught.

In spite of everything, Smith appears to have one of the most secure jobs in official Washington. He is a close friend of the president and served as Reagan's lawyer for 15 years. Reagan has dismissed the news stories, saying he has full confidence in his attorney general.

Aides say they see no likelihood that Smith would leave before the end of Reagan's term unless he believes he is damaging the president and decides to leave on his own.

But the controversy does raise questions about the man. Who is he? What has his impact been on the Justice Department? And what is behind the attacks?

The 64-year-old Smith is something of a hybrid. He is thought of as a Reagan Californian, but in fact he comes from a wealthy Boston family that traces its ancestry back to the Mayflower. He was born at the family's 30-room summer place in Wilton, N.H., a direct descendant of one of Harvard University's early presidents.

His father, president of a Boston-based telephone company, died when Smith was young; his mother eventually moved her son and two daughters to California where she had relatives. Smith went to the University of California at Los Angeles and then to Harvard Law School.

In 1946, he joined Gibson, Dunn and Crutcher, a Republican law firm that is the oldest and one of the largest in Los Angeles. He eventually met Ronald Reagan socially and became a member of the "kitchen cabinet" that has guided Reagan's political career for nearly two decades. But Smith has never been directly involved in politics himself.

Fred Dutton, who served with Smith on the University of California Board of Regents, observes, "Obviously, he has not handled Washington as well as he should have, but in California he was thought of as one of the more sophisticated, most intellectual personalities around Reagan."

Smith specialized in labor law on the side of management. "He was the main management expert on labor law matters in Southern California," Dutton said. "Before he became a senior partner, he was the management man keeping Los Angeles nonunion."

At the time of his appointment, Smith was one of three senior partners running the law firm and listed assets of several million dollars. He and his wife, Jean, a Stanford University Phi Beta Kappa graduate, lived in a comfortable San Marino home with a private tennis court.

One afternoon during vacation last August, Smith and his wife were relaxing in a suite at the Los Angeles Country Club, looking out over the golf course and the Santa Monica Mountains beyond. Outside the clubhouse, the impatiens and African violets were brilliant in the serene summer sun. Smith was clearly at home in the setting.

"Ideal," he said of his old West Coast life. "I had my tennis group, a couple of golf groups. It was just a very fine existence."

"Lotus-eating," said his wife. "I do think that he was perhaps too comfortable. You reach a point where whatever you're doing, no matter how pleasant, it's repetitive. Washington stirs up the brain cells."

"Going there was a major wrench," Smith said. "But after analyzing it back and forth, it was just something you had to do."

"He doesn't talk at dinner anymore," Jean Smith said. "Now he brings his papers and we sit in silence. I've taken to reading myself at meals. It's a beautiful family scene."

Although the couple now lives in a suite in the elegant Jefferson Hotel, life in Washington appears to be much more austere. They don't see their friends, the Reagans, as often as before. And Mrs. Smith said that her husband's obsession with the legal volumes he now brings home extends into the weekend when he sits in a robe, eating salads and reading.

In California, Smith was an avid downhill skier, golfer and tennis player. But because of his schedule, all that's left is the tennis, which he plays once a week with such people as FBI Director William H. Webster and Secretary of State Alexander M. Haig Jr. One of the few personal touches in his office is a tennis trophy on the mantle.

But by many accounts, the Smiths are one of the most popular and sociable couples in the Reagan Cabinet. "I see them everywhere," said Polly Fritchey, the Georgetown hostess and fund-raiser.

Jean Smith is active in volunteer work. She is chairman of the Opera Ball, serves on the boards of the symphony, the Red Cross and the Salvation Army, and is on the President's Commission for White House Fellowship.

But the Smiths' life style and obvious success on the Washington social circuit have led to charges--generally not for attribution--that the attorney general is "just a society lawyer."

"I've spent 30 years dealing with the Teamsters union and the Construction Workers union and a few others, and it's a little amazing to me," Smith said. "Anyone who said that hasn't done their homework because they obviously don't know what I'be been doing for most of my adult life. I've been called a lot of things, but the one thing I didn't expect to be called was a society lawyer."

Sen. Paul Laxalt (R-Nev.) has known Smith for years and said of the attorney general's move to Washington, "It's been a tremendous adjustment for him. He's never had any publicity or been in the spotlight."

Smith's close associates at Justice blame some of his problems on what they call his "New England reserve," his quiet, subtle manner. He is very private--not an easy person to get to know. His style, they say, is cool and professional. He is not given to emotional outbursts or back-slapping humor.

Trim, with carefully groomed silver hair and conservative, perfectly tailored suits, Smith is the very picture of a successful corporate lawyer. But his low-key approach causes him problems; aides say he not only is being denied credit for his own accomplishments, but also is being blamed for mistakes made by others in the administration because he is not one either to seek public recognition or to strike out at enemies.

One Justice Department insider said he believed that Smith and others in the administration had been burned because they came to Washington thinking the post-Watergate morality, in which the appearance of wrongdoing is as harmful as actual wrongdoing, was a thing of the past.

"I guess I would call it a kind of insensitivity," he said. "I don't like that word, but I can't think of another one."

Several examples of this "insensitivity" that someone more attuned to Washington political life would probably have avoided are these:

* Smith has ruffled feminist feathers by refusing to resign from two California clubs that do not allow women members.

* Just after his nomination he attended a party for Frank Sinatra, whose connections with organized crime figures caused Nevada gambling authorities to revoke his license on part of a Las Vegas hotel and casino. Smith later said he had not known about the organized-crime connections.

* Smith made headlines this month when word leaked that he had invested in two tax shelters--one allowing him to deduct $66,000 from his 1981 federal taxes after investing only $16,500 up front. There is nothing illegal about such an investment, although the Internal Revenue Service can fight the deduction.

Again, the sensitivity issue was raised.

"It was really embarrassing," said one department lawyer. "The ultimate conclusion is for the IRS to go to court to disallow the deduction. And who represents the IRS? We do. What Justice Department lawyer is going to want to go into court on a case that could go against the attorney general? He should have known better."

Smith announced Friday that he would limit his deductions in those investments to the amount he invested.

He also said that, to avoid the appearance of impropriety, he would return a $50,000 severance payment he received from a steel company of which had been a director. Persons moving from the private sector into government are prohibited from accepting certain kinds of salary supplements. He noted that a major law firm had assured him there was no ethical conflict.

Smith came to Washington knowing little about the kinds of law practiced in the Justice Department. He stunned Democrats and Republicans at his confirmation hearing by answering few of the questions. He conceded that he knew nothing about tax law, antitrust law and many of the other areas the department deals with. He would not even venture personal opinions on issues.

Perhaps as a result, there has been a widespread impression on Capitol Hill, even among Republicans, that Deputy Attorney General Edward C. Schmults is running the department.

But Schmults says, "That's absolutely false. There's one person running the Justice Department: Bill Smith. . . . I don't make a decision without making sure it's fine with him."

Associate Attorney General Rudolph W. Giuliani adds, "He is very much in charge. . . . His whole background is being a lawyer who managed a very large law firm."

Smith said, somewhat indignantly, "I've spent more time behind this desk than a good many of my predecessors. I'm very pleased with the way this department is run."

Major changes have taken place at the Justice Department under Smith. The two most noticeable are in the civil rights division, which has moved away from busing as a remedy for school desegregation and from quotas as an affirmative-action enforcement tool, and in the antitrust division, where big is no longer necessarily bad.

One of his proudest accomplishments is the selection of his staff. Even a lawyer who served as a top-level assistant to former attorney general Griffin Bell agreed that Smith had chosen an exceptionally capable staff. "They're conservative but they're very good," he said.

Bell added, "If you wanted someone to look after your affairs and your estate, he's the kind of person you'd get. And what's wrong with the government getting someone like that?

". . . When you get to the Washington scene," Bell continued, "they judge you about what you know about the nuances of politics. Well, a lot of people haven't lived in Washington all their lives. . . . He's the essence of a corporate lawyer. I like him. I think he's an excellent lawyer. He doesn't try to put on a lot of color."

But Smith has vocal detractors: in Congress, at the White House and among liberal and conservative groups.

Leaks from the White House staff questioning Smith's competence have been continuous.

Rivalry and bickering between the Justice Department and the White House staff have a long history. The situation for Smith was complicated even more by indications that White House chief of staff James A. Baker III and White House counselor Edwin Meese III would both like his job.

Smith said he believed many of the problems stemmed from his unwillingness to bend the law to suit the ideological agenda of some in the government.

"The Department of Justice, by virtue of its functions, is bound to have a certain tension, not only with the White House but also with other government agencies," he said. "We are in a position where we have to say no a lot. Certain people don't like that. . . . But we have to enforce the law. . . . That's one of our basic functions here."

In Congress, there have been widespread complaints that the department has been late providing positions on issues. conservatives were anxious, for example, for ideas from the department on bills to limit school busing for integration, to allow voluntary prayer in public schools and to limit the jurisdiction of federal courts.

House Republicans were also angered when Justice failed to respond last fall to repeated requests for a position on extending the Voting Rights Act. As a result, a much more liberal bill was adopted than the administration wanted.

One House Republican, complaining about that bill, said, "We never get a position until the last minute. By the time we get it, the war's almost over.

"He doesn't seem to know what the department does and doesn't seem to care. . . . I'm disappointed from the point of view of making policy. Nobody could understand Griffin Bell, but at least he was all over the Hill," he said.

One lobbyist for the New Right complains that Smith is not responsive to the conservatives who elected Reagan. Claiming that the department is ignoring conservative issues, he said, "He is surrounded by people who may be registered Republicans, but they're not conservatives or even Reagan Republicans. That department is populated with more country club, Elliott Richardson, Nelson Rockefeller Republicans than any other department in government."

But even many Republicans concede that Smith may not be the one to blame for slowness on voting rights and other major issues. The president said publicly that he wanted to devote the first year of his administration to the budget and tax agenda and perferred to postpone everything else to the second year.

Smith has been extremely active on Capitol Hill working for an overhaul of the immigration laws that appears to have excellent chances for passage. And he worked hard for passage of a comprehensive criminal code reform that is dead at least for this year.

He also has taken great interest in the issue of violent crime and drug abuse and was instrumental in combining the forces of the FBI and the Drug Enforcement Administration to fight narcotics trafficking.

Smith doesn't show his anger in public, but people close to him say that the attacks on his honesty and competance have been painful. "He's a man of such discretion, propriety and New England reserve that this is incredible to him," said Thomas P. DeCair, an aide.

Jean Smith conceded that the situation would be "upsetting to anybody. We are human beings. I vary from being angry, to wounded, to saying the heck with it. . . . He has not led what you would call a public life . . .never been exposed in the same sense."

Smith was making $325,000 a year in salary at Gibson, Dunn and Crutcher when he accepted Reagan's offer to become attorney general, a position that pays $69,630 annually.

After all the personal attacks and negative publicity, he was asked if he thought the move to Washington was worth the personal anguish that came with it.

"Sure, it's worth it," he said. "Good grief, this is an important public service. It's the kind of thing one both wants to and should do from time to time. It has been an interesting adjustment--for a lot of reasons. But it has a fascination that doesn't exist in private life."