U.S. Circuit Court Judge David L. Bazelon, whose legal opinions have influenced the thinking of a generation of lawyers and educators, announced yesterday that he will assume the semi-retired status of a senior judge on June 30.

Controversial and outspoken during almost 30 years as an appellate court judge-15 of those years spent as the chief judge of the U.S. Court of Appeals here-Bazelon is widely known as a liberal, activist judge. His career has spanned the terms of seven presidents-beginning with Harry Truman-and during his tenure as chief judge, the Court of Appeals here was generally regarded to be second in importance and influence only to the Supreme Court.

In a letter to President Carter released yesterday, Bazelon said that "resolving to step back a bit from a 30-year labor of love is necessarily difficult." But he did so, Bazelon said, knowing that Carter "will select as my replacement an individual with the vision and talent necessary to address the demanding challenges that will face our court in the years to come."

Harvard law professor Alan Dershowitz, once a clerk to the judge, said Bazelon's "enduring contribution" to the law "has been that he has pressed more questions on the system than any other judge . . . He has singled out the function of the Court of Appeals more than any other judge - to raise questions, open areas for discussion."

Bazelon, who will be 70 years old in September, came to the Court of Appeals in 1949 when he was 40, then the youngest man ever appointed to a federal judgeship. Within five years he had begun to provoke debate and controversy with his opinions. He has been a consistent advocate of safeguarding the rights of persons accused of crimes, of ensuring in practice as well as in theory that defendants were adequately represented in court and of bringing knowledge from other disciplines, particularly psychiatry, to bear on the criminal justice system.

Bazelon's effort to open up the legal system to more information, to prompt debate and to pose hard questions, is illustrated by his best known opinion involving the case of Monte Wayne Durham, a convicted burglar with a history of mental disturbance.

In that 1954 appellate court opinion, which propounded what came to be known as the "Durham Rule," Bazelon attempted to change the prevailing legal test for insanity. The old test held that a criminal could claim insanity as a defense only if it could be proven that the defendant could not distinguish between right and wrong or if the act was the product of an "irresistible impulse."

The "Durham Rule" said that a defendant should not be held criminally responsible if the crime was a product of a mental disease or defect.

But for Bazelon, the Durham case was not a chance to impose a new formula on American courts.Durham, Bazelon said in a recent interview, "was an effort to open the door to information-period. The door had been closed shut."

Bazelon hoped, with durham, that psychiatrists would be able, in the context of a criminal trial, to give juries some insight into what motivated a criminal.

The Durham case, Bazelon wrote in a concurring opinion when the Court of Appeals finally abandoned the Durham Rule in 1972, "fueled a long and instructive debate that uncovered a vast range of perplexing and previously hidden questions. And the decision helped to move the question of responsibility from the realm of esoterica into the forefront of the critical issues of the criminal law."

According to a former law clerk, Bazelon, who became chief judge of the Court of Appeals in 1962, believes that "most judges in America are janitors who sweep the dirt under the rug. He thinks it's critically important to surface the dirt under the rug."

"Any wiseacre can go around asking a lot of hard questions without knowing answers," Bazelon said last week. "But I honestly believe you're never goint to move in on anything unless you confront it."

The behavioral sciences, Bazelon said during the interview, had developed information suggesting that a person's genetic makeup or early childhood experiences might color his or her behavior. "In a moral society," Bazelon asked, "do you weigh that before you impose moral guilt or do you ignore it? I wanted people to confront and grapple with the problem. I don't know how to settle it."

"The Baz has wanted the courts to confront the issues," said Joel Klein, a former law clerk. "He has constantly played that role, raising issues others consciously avoided or never thought about."

"Bazelon, despite what people think, does not have a program to carry out," said law professor Dershowitz. "He keeps saying, 'I don't have the answers. I just know the problems.'"

Bazelon, according to Dershowitz, prodded lower court judges to produce more and better information during trials and sharpened issues for decision by the Supreme Court. "He sees his job as forcing the Supreme Court to confront these issues," Dershowitz said.

During the 1960s, Bazelon and Chief Justice Warren E. Burger, then a circuit judge on Bazelon's court, carried on a highly publicized and increasingly bitter public debate over the rights of criminal defendants. Although cordial to each other in public, the two men developed an animosity toward each other that became an open secret in legal circles.

In later years, Bazelon wryly claimed that he was responsible for Burger's elevation to the Supreme Court by President Nixon in 1969. "I was the foil," Bazelon said, with Burger's tough law-and-order opinions playing off Bazelon's demands for upholding constitutional safeguards.

Bazelon still maintains the postitions, in private and public, that indelibly marked him as a liberal judge. "You can't have criminal justice without social justice," he said recently. "That ties into everything."

"It is easy," Bazelon told a conference of prison officials in 1976, "to concede the inevitability of social injustice and find the serenity to accept it. The far harder task is to feel its intolerability and seek the strength to change it."

He has insisted, in a number of cases, that the Court of Appeals has an obligation to look at how effectively court-appointed lawyers represented their clients in criminal cases. "In most cases they give you a warm body," Bazelon said. "I'm not saying there isn't effective counsel, but in most cases, it's a sham."

During his 30 years on the bench, Bazelon has also been active on a variety of commissions, conferences and organizations concerned with social and psychological problems.

A stern, forbidding figure in court, Bazelon is warm and gregarious in private, expressing himself in colorful language, laced with Yiddish expressions and a seemingly endless supply of jokes and "stories" - some turned against himself - to make his point.

Although Bazelon could have remained as chief judge of the court until he turns 70 in September, he voluntarily relinquished the chief judgeship in March 1978 to allow his close friend and colleague Circuit Judge J. Skelly Wright a longer tenure as chief judge. Wright must step down from the chief judgeship in 1981, when he turns 70.

Bazelon, who could have remained a full-time circuit judge indefinitely, made clear that he intends to maintain his busy schedule. He said he intends to be an active senior judge giving "substantial service" to the court as well as continuing his interests outside the court.

Asked how he would like his period as a judge to be remembered, Bazelon pondered a moment before he replied. "For the effort to make people aware," he said. CAPTION: Picture, U.S. Circuit Judge David L. Bazelon: "You can't have criminal justice without social justice." By John McDonell-The Washington Post