When a fellow judge sends him a draft opinion for review, said a former appeals court clerk, Antonin Scalia "will send back a memo praising the opinion, and then say, 'I will join if you make the following 19 changes.' "

That number might be exaggerated, but his liberal colleague on the appeals court here, Judge Abner J. Mikva, said, "He understands the doctrine of collegiality and has in fact found middle ground, and I think he's good at it." However, Mikva said, once Scalia has decided a certain way, "there's no shaking him loose."

By all accounts, Scalia, President Reagan's choice for the Supreme Court, has been convinced for years of the correctness of his positions and has not been shy about saying so.

"When Nino Scalia had done the work on the issue and had come to a conclusion, that really was it," former deputy attorney general Edward C. Schmults recalled of Scalia's work as head of the Justice Department's Office of Legal Counsel in the Ford administration. "He didn't change his mind because a Cabinet secretary or even the president would have liked a different result."

Even at Harvard Law School in the late 1950s, where Scalia was far more conservative than his liberal classmates of the Warren Court era, "If you didn't feel like having a good debate about something, you'd better avoid him," said Philip B. Heymann, who now teaches law there.

"He was less enthralled with the liberal aura of the times than the rest of us," said Daniel K. Mayers, Scalia's fellow officer on the Harvard Law Review and now a partner at Wilmer, Cutler & Pickering here. "I remember him saying 25 years ago over a beer that he just had grave doubts that government could do much to change the plight of disadvantaged people."

Scalia, 50, never changed. The times did.

Today, Scalia's conservative views -- refined and expounded over nearly three decades as a lawyer, teacher and judge -- appear perfectly attuned to the era of Ronald Reagan. Those views and the contacts and reputation for excellence he gained while serving in the Nixon and Ford administrations have now led him to what he described Tuesday as "the culmination of a dream" -- a nomination to the Supreme Court.

"There's a touch of lightning with all of them," University of Virginia Law Prof. A.E. Dick Howard said of Supreme Court appointments through history. But Scalia "had positioned himself over the years, if not for the court, for something like it."

Reagan's choice to fill the seat of Justice William H. Rehnquist, chief justice-designate, emerges in discussions with his family, friends and colleagues as a man of many talents and many paradoxes.

He is a serious, respected scholar who delights in arguing arcane points of administrative law, his specialty, or broad issues of political philosophy. He is also a gregarious, back-slapping host who enjoys sitting down at the piano after a cocktail party and leading a group in belting out tunes from the 1940s and 1950s. He is, Mikva said, "not what you think of as a typical conservative Supreme Court justice who scowls at the world."

Although his family had strong ties to the Democratic Party, Scalia was a staunch conservative from an early age. Despite being the first Italian-American nominated to the Supreme Court, the son of an immigrant, he is, in the view of some, insensitive to the hardships faced by other minorities.

Even those who disagree with Scalia's conservative views say his ready wit and informal manner make working with him a delight. Yet he has a quick temper at times and can be as intolerant of error in others as he is of his own. "He'd catch a mistake that we had made," said former clerk Paul Cassell, and, "he'd say 'Well, it's hard to get it right.' He wanted everything perfect."

Last year, Scalia's clerks had a calligrapher inscribe a plaque with the familiar refrain that had become something of a standing joke among them: "It's hard to get it right."

Most of all, said federal appeals court Judge Frank Easterbrook, for years Scalia's conservative colleague at the University of Chicago Law School, Scalia is one of "very few people who want to become judges for the purpose of diminishing the power of judges."

Scalia was born March 11, 1936, in Trenton, N.J., the only child of S. Eugene Scalia and Catherine Panaro Scalia. From his father, Antonin Scalia inherited a tradition of scholarship; from his mother's family, political acumen and an interest in law.

His father was a deeply religious Roman Catholic who emigrated to New York from Italy as a young man. He was a professor of Romance languages at Brooklyn College and an authority on Dante.

"Even on his deathbed he was reciting 'Elegy Written in a Country Chuchyard,' by Thomas Gray," said his sister-in-law, Eva Panaro.

Antonin Scalia's mother was a first-generation Italian-American, an elementary school teacher. Her father was a Trenton, N.J., tailor who saw that his seven children went to college. He "spoke broken English, but he liked the law very much," said his son, Anthony Panaro. "He had a lawyer friend, and he would go to the courthouse and sit there all day and listen to the case he was pleading."

Another of Judge Scalia's uncles, Vincent Panaro, was an assemblyman in the 1960s and the first Democrat elected mayor of Ewing Township, outside Trenton, where the Panaros still live side-by-side in a cluster of houses they refer to as "the family homestead." Vincent Panaro later became the county prosecutor, and Eugene Scalia once called him a role model for his son, Antonin.

Scalia's parents died within three weeks of each other this winter.

The Scalias lived at the Panaro family homestead until Antonin was ready to enter grade school. The family then moved to Elmhurst, N.Y., then a predominantly Irish and Italian middle-class neighborhood in Queens. Antonin Scalia attended a Jesuit school in lower Manhattan, Xavier Military Academy. The Scalias returned to Ewing Township when Antonin completed high school and left for college.

Those who knew Scalia as a young man said his intellectual abilities dwarfed those of everyone around him. "People just competed for second, he was so superior academically," said high school friend William Stern.

When Xavier put on Shakespeare's "Macbeth," Scalia had the lead role. John Gallagher played Lady Macbeth in the all-male production, and remembers vividly his agony at having to wear a gown for a dress rehearsal.

"I was embarrassed and taking a ribbing from my classmates," Gallagher said. Scalia, who Gallagher viewed as "kind of an awesome figure," recognized Gallagher's discomfort and pulled him aside. "He said, 'Look, I know you're going through a tough time, but don't let them see it's bothering you -- they'll just do it more. And think of the part; it's really a masculine part because she's so domineering.' "

Scalia finished first in his class and was valedictorian. Then he attended Georgetown University and was first in his class and valedictorian.

"He had a European education -- a classical education," said Richard Coleman, a Los Angeles attorney who developed what was to become a lifelong friendship with Scalia while at Georgetown. Coleman said he thinks Scalia's training, which included six years of Latin and five years of Greek, gave him "a long-range viewpoint," one that allows him to see contemporary issues in a far-reaching historical and philosophical context.

"He's an intellectual and a traditionalist," said William Stern, a friend from high school who served as chairman of Democrat Mario M. Cuomo's 1982 New York gubernatorial campaign. "So many people associated with the right over the years have been haters. Nino is not a hater."

Scalia graduated magna cum laude from Harvard in the spring of 1960. That fall, he married Maureen McCarthy, who had just graduated from Radcliffe. "I think she told me that, at the time, their parents regarded it as a mixed marriage -- she's an Irish Catholic and he's an Italian Catholic," said Rex E. Lee, former solicitor general, a friend of Scalia's.

For the next six years, Scalia practiced law with a prestigious Cleveland firm, now called Jones, Day, Reavis & Pogue, then moved into academia, teaching at the University of Virginia for three years.

In 1971, he joined the Nixon administration as general counsel in the new Office of Telecommunications Policy; by the next year, he had been promoted to chairman of the Administrative Conference of the United States, an interagency group that studies issues affecting regulatory agencies. In 1974, Scalia served as assistant attorney general in charge of the Office of Legal Counsel, grappling with such subjects as the ownership of Richard M. Nixon's presidental papers and the permissible intelligence-gathering activities of the Central Intelligence Agency and Federal Bureau of Investigation.

Scalia left public office in 1977, spending a year as a visiting scholar at the American Enterprise Institute (AEI). He then returned to teaching at the University of Chicago, whose law school has attracted a number of conservative scholars and where the Scalias settled their large family into an old fraternity house. They now have nine children, ages 5 to 24.

Scalia also stayed in close touch with the Washington and legal establishments, serving as chairman of the American Bar Association's Administrative Law Section along with editing and writing for the AEI's Regulation magazine.

By the time Reagan took office, Scalia "had really become quite a well-known figure," said Jonathan Rose, who at the start of the Reagan administration served as head of the Justice Department's Office of Legal Policy, which screened potential judges.

Scalia came close to being appointed solicitor general during Reagan's first term. Then, in 1982, he was tapped for a judgeship on the U.S. Circuit Court of Appeals here. Swearing him into office was Rehnquist.

The appellate court here is regularly described as second in importance only to the Supreme Court. The circuit court here is also a court in transition, as two decades of domination by liberal judges give way to a new conservative majority.

For a body that is undergoing a fundamental shift in the balance of power and politics, the court has, so far, remained surprisingly congenial. Many of those familiar with the inner workings of the court give Scalia a share of credit for that collegiality.

"He's one of the easiest judges to visit with," said Mikva. "He'll come try something out with you in person rather than over the phone."

If Scalia's dealings with his colleagues on the appeals court are any indication, he is apt to be an adept advocate of his views at the high court as well, if nominated and confirmed. Many observers credit him with helping pull Judge Ruth Bader Ginsburg, a former Columbia Law School professor who many had expected to align with the court's liberal wing, further to the right.

Scalia blends charm and an initial willingness to debate with a near-complete inflexibility once he has staked out a position.

That attitude prompted clerks for some of the more liberal judges last year, partly out of exasperation, partly out of grudging admiration, to dub Scalia "The Ninopath," referring to what they saw as an almost pathological unwillingness to bend.

Undergirding Scalia's judicial philosophy is a vision of a limited role for the courts.

"Where do rights exist, and where do they not exist? That is another judgment that the courts have been increasingly willing to arrogate to themselves," Scalia said during a 1978 debate at the American Enterprise Institute.

"In the abortion situation, for example, what right exists -- the right of the woman who wants an abortion to have one, or the right of the unborn child not to be aborted?" he asked. Courts, Scalia added, "have gone too far. They have found rights where society never believed they existed." He cited, in addition to abortion, cases striking down death penalties and requiring busing to remedy segregation. With busing, Scalia said, "It was not necessary for the courts to step in and say what must be done, especially in the teeth of an apparent societal determination that the costs are too high in terms of other values of the society."

Part of Scalia's judicial philosophy appears influenced by his background.

"My father came to this country when he was a teen-ager," Scalia wrote in a 1979 law review article attacking affirmative action. "Not only had he never profited from the sweat of any black man's brow, I don't think he had ever seen a black man.

"To compare the racial debt" of ethnic group members "with that of those who plied the slave trade, and who maintained a formal caste system for many years thereafter, is to confuse a mountain with a molehill. . . ," Scalia wrote. "Yet curiously enough, we find that in the system of restorative justice established by the Justice Lewis F. Powells and the Justice Byron R. Whites, it is precisely these groups that do most of the restoring."

Scalia mockingly set forth "a modest proposal, which I call R.J.H.S. -- the Restorative Justice Handicapping system. . . . Under my system each individual in society would be assigned at birth Restorative Justice Handicapping Points, determined on the basis of his or her ancestry. Obviously, the highest number of points must go to what we may loosely call the Aryans -- the Powells, the Whites, the Justice Potter Stewarts, the Chief Justice Warren E. Burgers, and in fact (curiously enough), the entire composition of the present Supreme Court, with the exception of Justice Thurgood Marshall. . . .

"It will, to be sure, be difficult drawing precise lines and establishing the correct number of handicapping points," Scalia wrote, "but having reviewed the Supreme Court's jurisprudence on abortion, I am convinced that our justices would not shrink from the task."

On the bench, Scalia has put his conservative principles into action. He consistently applies technical legal doctrines that limit access to the courts, defers to executive branch authority and adopts a narrow reading of constitutional provisions.

For example, Scalia disagreed in the court's 1983 decision upholding the right of protesters from the Community for Creative Nonviolence to sleep in Lafayette Square as protected speech. Scalia said the reason he wrote a separate dissent was "flatly to deny that sleeping is or ever can be speech for First Amendment purposes. That this should seem a bold assertion is a commentary upon how far judicial and scholarly discussion of this basic constitutional guarantee has strayed from common and common-sense understanding."

The Supreme Court later overturned the appeals court decision, but did not go as far as Scalia in its definition of what constitutes protected speech.

"He's going to be a superb justice," Judge Easterbrook said. "The man is incredibly intelligent, he has a firm sense of the meaning of the constitution and the role of judges in the legal system, and he adheres to his own sense of that."

Staff writer Benjamin Weiser and staff researcher Michael Slevin contributed to this report.