Supreme Court Justice Clarence Thomas is famously quiet in the court. But he made his first comments in a decade on Feb. 29. (Claritza Jimenez/The Washington Post)

Supreme Court Justice Clarence Thomas is famously quiet in the court. But he made his first comments in a decade on Feb. 29. (Claritza Jimenez/The Washington Post)

The late justice Byron White is credited with the observation that the addition of a new justice to the Supreme Court creates a completely new body that is different in dynamics and practice from its predecessor.

Last week showed that the same can be true of a loss.

With Justice Antonin Scalia’s chair empty and draped in mourning black — the court’s booming conservative voice silenced — the Supreme Court, now with only eight members, seemed transformed in substance and style.

Start with the obvious: On Feb. 29, Justice Clarence Thomas shocked the courtroom by asking a question during oral arguments, the first time he had done so in 10 years. He was defending gun rights, taking up the slack on an issue that he and his closest ally, Scalia, had declared was being treated too cavalierly by the other justices.

[Thomas asks first question during oral arguments in a decade]

During Wednesday’s hearing on Texas’s abortion restrictions, it was the court’s four liberals who filled the space that Scalia left.

They dominated the session the way Scalia used to do when he cared passionately about a subject. Justices Sonia Sotomayor and Ruth Bader Ginsburg all but commandeered the proceeding, ignoring Chief Justice John G. Roberts Jr.’s efforts to bring the interrogation to an end.

[Liberal justices unite in arguments over Texas abortion restrictions]

That was a change in style, and there’s more to say about it. But there were also indications that without Scalia to shore up the court’s conservative wing, a shift in the court’s jurisprudence is underway as well.

Dow Chemical, for instance, announced that it would settle a nearly $1 billion antitrust judgment instead of pursuing its plans to take the fight to the high court.

“Growing political uncertainties due to recent events with the Supreme Court and increased likelihood for unfavorable outcomes for business involved in class-action suits have changed Dow’s risk assessment of the situation,” the company said.

[Dow Chemical settles suit because of Supreme Court uncertainty]

Those changed circumstances were apparent in another of the court’s decisions last week.

A month after granting an apparently unprecedented stay to temporarily freeze the Obama administration’s signature regulation on climate change, the court denied a similar request to block a different air-pollution rule.

Roberts rejected a request from Michigan and other Republican-led states to stay the Mercury and Air Toxic Standards rule. The regulation was adopted by the Environmental Protection Agency three years ago to tighten restrictions on a class of harmful pollutants that are byproducts of burning coal.

On Feb. 8, just five days before Scalia’s death and with him in the majority, the court voted 5 to 4 to freeze implementation of the Clean Power Plan, the Obama administration’s main avenue to address climate change by limiting greenhouse-gas pollutants. The move was highly unusual because no lower court had ruled on the plan’s legality.

Last week’s request had different circumstances, but it must have been clear to Roberts that there would not be five votes to issue a stay. He denied the request without even referring it to the full court.

[Supreme Court backs EPA this time in emissions case]

And on Friday night, the court overruled a panel of the U.S. Court of Appeals for the 5th Circuit and delayed a Louisiana law that would have forced all but one of the state’s abortion clinics to close. Because the action came just after the justices were to have met to discuss the Texas case, abortion rights providers took that as a positive sign.

It seems likely that the clinics might have been given the reprieve even if Scalia were voting; the Texas clinics received a similar accommodation last summer. But without Scalia, Thomas was the only justice to register an objection.

As Dow’s lawyers noted, there is too much uncertainty about the court to make many predictions about its future. The standoff between Obama and Senate Republicans about a replacement for Scalia could mean an eight-member court for at least a year. A flurry of 4-to-4 decisions might blunt the court’s influence and postpone controversial decisions.

But in Wednesday’s abortion-case hearing, it was hard not to sense a different court.

[Read the transcript of arguments in Whole Woman’s Health v. Hellerstedt]

Thomas asked no questions, and Justice Anthony M. Kennedy appeared to be the undecided man in the middle. So it fell on only two justices — Roberts and Justice Samuel A. Alito Jr. — to make the conservative case for upholding the challenged Texas provisions.

Texas says concern for patient health led to the requirements that clinic doctors have admitting privileges at nearby hospitals and that the clinics meet the high standards of surgical centers. The clinics argued that the requirements are medically unnecessary and in some cases impossible to satisfy and that they are a pretext for closing clinics.

Roberts and Alito made time-consuming and technical legal points about whether the case is in the proper form for the court to decide and whether the record contained evidence to support the contention that the law would require 75 percent of the state’s clinics to close.

The liberals were more aggressive. Ginsburg came to the aid of Stephanie Toti, the attorney representing the Center for Reproductive Rights. The court had taken up so much of her time, Ginsburg said, that she hadn’t really been able to get to the heart of her argument.

“Can she have some time to address the merits?” Ginsburg asked Roberts. He agreed to an extension.

It was the only time they bothered to ask.

When it was Texas Solicitor General Scott A. Keller’s turn at the microphone, Justices Stephen G. Breyer and Elena Kagan joined Sotomayor and Ginsburg in a pummeling. Sotomayor was particularly blunt.

“According to you, the slightest health improvement is enough to impose on hundreds of thousands of women — even assuming I accept your argument, which I don’t, necessarily, because it’s being challenged — but the slightest benefit is enough to burden the lives of a million women,” Sotomayor said. “That’s your point?”

Later, after Keller’s argument time had expired, Sotomayor and Ginsburg continued their questioning, an extremely rare event at a court that lives by rules. Sotomayor spoke six more times; Ginsburg spoke four more.

At one point, Kennedy leaned over to Roberts and said something the courtroom could not hear. But the court transcript later supplied the comment.

“Sonia is off,” Kennedy said.

That can be taken two ways. But in the context of the day, it seems the most likely interpretation is “off and running.”