If President Carter is to be faulted for lowering his proclaimed standards in the appointment and prolonged defense of his retiring budget director, Bert Lance, he is entitled to some credit for observing the highest of standards in making two important judicial appointments during the past week.

The appointments are of lasting significance, not merely because the courts in question are junior only to the U.S. Supreme Court, but also because the quality of the appointees is a reassuring sign that Carter, in contrast with Richard Nixon, intends to promote the integrity and prestige of the U.S. judicial system.

Civil-rights leaders, and civil libertarians as well, are certain to hail the appointment of U.S. District Judge Leon Higginbotham Jr. of Philadelphia to the Third Circuit Court of Appeals. He succeeds the retired Francis L. Van Dusen.

While Higginbotham, who is black, is only 49 years old, he already has achieved a distinguished reputation as a jurist. He was made a district judge while still in his middle 30s. He is a graduate of Antioch and the Yale Law School and is regarded as moderate to liberal.

The appointment to the First Circuit Court of Appeals, which serves New England, went to U.S. District Judge Hugh Bownes of Bow, N.H., who is 57 and a graduate of Columbia University Law School. Before going on the bench in 1968, Judge Bownes was a noted trial lawyer.

He also served as mayor of Laconia, N.H., and as New Hampshire's Democratic national committeeman. During World War II he was a major in the Marine Corps, winning a Silver Star after being badly wounded in the Pacific. Like Higginbotham, he is perceived as a moderate-liberal, or the other way around.

Several days before the Bownes and Higginbotham appointments, there was one in the District of Columbia that also was hailed in the legal profession when the President named Louis Oberdorfer to the federal bench. Oberdorfer, a senior partner in the prestigious Washington law firm of Wilmer, Cutler and Pickering, is a Yale Law School product and a former law clerk of the late Supreme Court Justice Hugo Black.

Perhaps the most inspiriting thing about all these appointments is that they indicate that President Carter intends to make good on his pledge to consult the public as well as the politicians in choosing judges. Higginbotham, Bownes and Oberdorfer were all approved by special 11-man presidential panels composed of lawyers and nonlawyers, men and women, and representatives of minorities.

The promotion of Higginbotham has evoked special interest because his appointment puts him potentially in line for the Supreme Court seat now occupied by Justice Thurgood Marshall, the first black ever named to the highest court.

Marshall, who will be 70 next year, has been in chronically poor health in recent years, and many think he may resign while Carter is President to ensure that he will be replaced by another liberal. If Marshall does retire, the President will have no trouble finding another distinguished black as a replacement.

The possibilities include Solicitor General Wade Hampton McCree Jr., a former federal judge, and two remarkable women, U.S. District Judge Constance Motley of New York, and Patricia Harris, the Secretary of Housing and Urban Development.

It is no secret that Carter is eager to be the first President to put a woman on the Supreme Court, so if Marshall retires, the opportunity to name a woman who is also a black could be irresistible.

So many Supreme Court decisions in the last year or two have been decided on a 5-to-4 basis that even one Carter appointment could signficantly alter the personality of the court. Next year, five of the nine justices will be between 70 and 72 years old, so it seems likely that Carter, if he so chooses, could turn the court liberal again, especially if he serves two terms. In less than six years, Richard Nixon put four conservatives on the court. Former President Ford made one appointment, and he named a moderate, Justice John Paul Stevens.

Every President talks about putting a woman on the Supreme Court, but it is a good bet that Carter will be the first to do it. Further, if vacancies make it possible, it is also a strong probability that he will restore the traditional Jewish seat on the high court.

For more than half a century, from the appointment of the late great Louis Brandeis in 1916 to the Nixon-Ford administrations, there was always at least one Jewish justice on the court, and long experience proved it a sound tradition.

Presidents invariably pay lip service to a "balanced" court, but all of the nine current justices are males, and seven of them are WASPs. Carter is going to have the privilege of making the court more representative. If he makes the most of it, the country will be in his debt.