Over some three hours of questioning by a Senate interrogator, Dr. Ford made a compelling case that he did. Her testimony was raw and powerful, frighteningly vivid, and in the view of many (including me), deep-in-the-gut credible. It was nearly impossible to watch Dr. Ford’s retelling of her experience that dark night—in which she alleged that a drunken Kavanaugh held her down against her will, groped her, and put his hand over her mouth to muffle her screams—without being moved by Dr. Ford’s sheer courage in telling it. It was hard to watch Dr. Ford’s terrified, but sober testimony and not think of the millions of other women and girls who have gone through a horror just like it.

In his own hours of testimony that followed Dr. Ford’s, Kavanaugh—who is now a judge on the U.S. Court of Appeals for the D.C. Circuit—vehemently, emotionally, and angrily denied that the incident occurred or that he’d ever sexually assaulted anyone.

Though Dr. Ford identified a second man who she says was there in the room with Kavanaugh—an alleged participant in and eyewitness to this crime—the Republican mandarins presiding over the Senate inexplicably did not demand his testimony as well. Nor, inexplicably, have they called for an FBI investigation that might uncover further evidence that could help corroborate or refute Dr. Ford’s accusation.

So as to that single essential question—Did Brett Kavanaugh sexually assault Christine Blasey?—we are left without a definitive conclusion. And if the Senate does vote to elevate Judge Kavanaugh to the U.S. Supreme Court, that question will continue to ring unanswered in the minds of millions of Americans, perhaps for decades.

But then, Thursday’s testimony provoked another question as well: Does Judge Kavanaugh have the temperament to be a Justice Kavanaugh, to sit on the highest court of the land?

And that question we can answer from the evidence provided.

“The most important predictors of success on the Supreme Court, are not academic brilliance, philosophical consistency, or methodological ambition,” wrote Jeffrey Rosen, a professor at the George Washington University Law School, the president and CEO of the National Constitution Center in Philadelphia, and one of America’s most distinguished scholars of the Supreme Court. “Instead, many of the most successful Supreme Court Justices are those who get along well with their colleagues, are able to compromise, and can set aside their own ideological agendas in the interest of preserving the institutional legitimacy of the Court. By contrast, the most brilliant and philosophically ambitious Justices have often alienated their colleagues and subverted the ideals they hoped to promote.”

Court scholars refer to this ability to find common ground—to persuade through collegial argument, not polemic—as “judicial temperament.”

John Marshall, who Rosen and many others consider to be “America’s greatest Chief Justice,” was the exemplar of this. “Marshall was modest, humble, and had no airs,” wrote Rosen. “He was famously mistaken for a servant in the Richmond market when a newcomer threw him a coin and hired the Chief Justice to carry his turkey home, which Marshall did without complaint.”

That personal and philosophical modesty was also reflected in the court’s opinions during the politically explosive era of the early 19th century, when the young American republic was charting its path forward. “Marshall embodied judicial restraint, defined neutrally as a reluctance to strike down very many laws, and almost all of his decisions were readily accepted by national majorities,” Rosen writes.

The Judge Kavanaugh whom the nation witnessed yesterday, however, seemed far from this paradigm. The man who offered sworn testimony on Thursday was belligerent and fiercely partisan, blaming the committee’s obvious requirement to fairly hear Dr. Ford’s accusation on a conspiratorial plot: “Revenge on behalf of the Clintons, and millions of dollars in money from outside left-wing opposition groups,” as Judge Kavanaugh alleged.

The man who testified yesterday sounded not like a Supreme Court justice, but rather like yet another Republican member on the Senate Judiciary Committee, engaging in not only verbal combat with Democratic senators, but also—quite remarkably—seeming to threaten potential retribution: “And as we all know,” he said, “in the United States political system of the early 2000s, what goes around comes around.”

Members of the U.S. House of Representatives serve two-year terms. Presidents serve four. Senators, six. As much as Americans decry the rancorous partisanship that now defines our federal governance, the Republic can survive it. Voters have the power, after all, to cast the entire crop of elected officials out if they so choose.

But those named to the Supreme Court serve a lifetime. We can’t afford to risk giving someone that authority to change American life when he may not have the self-restraint to control his own temper.