Supreme Court Justice William H. Rehnquist, in a television interview to be aired Saturday, says the court's recent rulings are not "an unfortunate chipping away of civil liberties," as some critics have charged.

The Constitution requires some civil-liberties claims to be upheld, Rehnquist said, but that does not mean that the court is required to decide "unthinkingly" in favor of anyone who makes such claims. To do so would "be a recipe for anarchy," he said.

Rehnquist and Justice Harry A. Blackmun were interviewed in September for an hour-long ABC documentary on the court.

The justices' comments are in line with what they have said in opinions, articles and speeches to lawyers. But their willingness to be interviewed is a significant break with the traditional reticence of Supreme Court justices, particularly toward television cameras.

In addition, it is the first time that Rehnquist, on the court since 1972, has agreed to a televised interview. He is the third of the present justices to appear before the cameras; Blackmun did it in 1982, and Chief Justice Warren E. Burger has done so on three occasions, most recently this year.

ABC asked all nine justices to appear but only Blackmun and Rehnquist agreed.

The documentary's producers said Rehnquist agreed on the condition that he be allowed to edit his comments. ABC showed him the portions that it intended to broadcast, and he declined to exercise that option.

Both justices were interviewed by Harvard law Prof. Arthur Miller. Rehnquist indicated that he would not have agreed to the interview had he been questioned by a reporter, according to producer Ann Garfield Black. Blackmun set no conditions on his interview.

The documentary focuses on the court's handling of criminal law, school prayer and right-to-life issues.

Blackmun and Justices Thurgood Marshall and John Paul Stevens, members of the moderate-to-liberal wing, criticized the conservative majority in speeches last summer, leading to speculation about high tension at the court.

For the most part, Blackmun and Rehnquist limit their ABC comments to generalized observations about the court.

Blackmun said he assumes that a "pendulum swing" is inevitable as some of the court's older members -- five justices are over 75 -- leave, but added that he hopes it will be a gradual shift. "Abrupt changes in legal philosophy would be hard on the nation," he said.

"It's very much a cyclical thing," Rehnquist agreed. "I think the Burger court has decided some cases against claims of civil liberties that perhaps the Warren court might have decided the other way, though there's no way of telling that." Earl Warren preceded Burger as chief justice.

Asked whether the justices were capable of "handling such fundamental issues" as treatment for severely handicapped infants and the right to die, Rehnquist said:

"There probably is no very good reason for suspecting that we're more capable of handling that kind of issue than any other nine people you might get a hold of. But we happen to hold the commissions, and . . . have the cases thrust upon us."