Chief Justice John G. Roberts Jr. closed out the Supreme Court’s term on Friday with a warning to justices to cut out the carping, saying that the increasingly harsh language they’re using in their opinions to attack each other’s rulings is hurting the court.

He issued the admonition in the court’s final decision of the year, a 6-3 ruling halting President Biden’s student loan forgiveness program. That ruling prompted a fierce dissent from the three Democrat-appointed justices, who said the high court was breaking all the norms of how the judiciary should operate.

Chief Justice Roberts said that went too far.

“It has become a disturbing feature of some recent opinions to criticize the decisions with which they disagree as going beyond the proper role of the judiciary,” he wrote.

But far from an exotic exercise of judicial power, he said the court used “traditional tools of judicial decisionmaking” to reach its ruling.

“Reasonable minds may disagree with our analysis — in fact, at least three do,” he wrote, pointing to the dissenters. “We do not mistake this plainly heartfelt disagreement for disparagement. It is important that the public not be misled either. Any such misperception would be harmful to this institution and our country.”

The caution comes at the end of a tumultuous term for the court, which has been battling allegations of ethical lapses and polls showing plummeting confidence in the court’s impartiality.

It also comes after a couple of years of monumental decisions that overturned the Roe v. Wade decision that established a national right to abortion, struck down some state gun control laws and ruled against affirmative action policies used by many of the country’s most prominent universities.

Friday brought two more major rulings.

In one, the court said LGBT individuals cannot force creative businesses to serve them when it would mean the businesses would have to express statements that run contrary to what they believe.

In the other ruling, Mr. Biden’s student loan forgiveness program — a major wish-list item for the political left — was erased.

Justice Elena Kagan, dissenting in that ruling, said the Republican-appointed justices were turning the court into a super-legislature, taking up a case they should have rejected in the first place and using it to settle policy disputes between the White House and Congress.

“So in a case not a case, the majority overrides the combined judgment of the Legislative and Executive Branches, with the consequence of eliminating loan forgiveness for 43 million Americans,” she wrote.