If you've ever believed that people can disagree passionately about politics and still respect and care for each other as friends, the friendship of Justice Antonin Scalia and Justice Ruth Bader Ginsburg was a comfort and an inspiration.

He was the Supreme Court's most outspoken conservative; she is its most outspoken liberal. But their friendship became famous, not just because of its odd-couple unexpectedness but because their mutual respect and affection for each other was obviously genuine.

They and their families spent New Year's Eve together every year. They rode together on an elephant in India (Scalia joked that Ginsburg betrayed her feminism by sitting behind him), and Scalia watched Ginsburg go parasailing in the south of France ("She's so light, you would think she would never come down. I would not do that").

So it's no surprise that of all the tributes to Justice Scalia, who died Saturday of an apparent heart attack at the age of 79, Justice Ginsburg's is uniquely moving. It's a tribute to Scalia as an interlocutor, a fellow opera lover — including a reference to the opera Scalia/Ginsburg: A (Gentle) Parody of Operatic Proportions, which debuted in 2015 — and a "best buddy."

Toward the end of the opera Scalia/Ginsburg, tenor Scalia and soprano Ginsburg sing a duet: 'We are different, we are one,' different in our interpretation of written texts, one in our reverence for the Constitution and the institution we serve. From our years together at the D.C. Circuit, we were best buddies. We disagreed now and then, but when I wrote for the Court and received a Scalia dissent, the opinion ultimately released was notably better than my initial circulation. Justice Scalia nailed all the weak spots—the 'applesauce' and 'argle bargle'—and gave me just what I needed to strengthen the majority opinion. He was a jurist of captivating brilliance and wit, with a rare talent to make even the most sober judge laugh. The press referred to his 'energetic fervor,' 'astringent intellect,' 'peppery prose,' 'acumen,' and 'affability,' all apt descriptions. He was eminently quotable, his pungent opinions so clearly stated that his words never slipped from the reader’s grasp. Justice Scalia once described as the peak of his days on the bench an evening at the Opera Ball when he joined two Washington National Opera tenors at the piano for a medley of songs. He called it the famous Three Tenors performance. He was, indeed, a magnificent performer. It was my great good fortune to have known him as working colleague and treasured friend.

It's easy to mourn the lack of civility in contemporary American politics; politicians on both sides talk glowingly about the time when Ronald Reagan could invite Democratic House Speaker Tip O'Neill to the White House for a drink to work out a conflict. It's just as easy to say that civility is for people who don't have the courage of their convictions — that if people genuinely disagree about what is best for America, they shouldn't have to put that aside for the sake of small talk.

What makes Ginsburg's statement remarkable is that it shows how superficial both sides of the civility argument are.

The respect that Ginsburg's statement shows for Scalia's intellect — that she could trust him to point out the flaws in her arguments — also reveals a respect for her own, to know the difference between a genuine agreement of principle and an error that needed to be corrected. But more importantly, the statement shows that it's okay for people in politics to spend time cultivating other interests — like opera — and that those can be a genuine basis for friendship in their own right.

Arguably, that's easier for appointed judges than it is for elected officials. It's still rare. And it's still worth celebrating.

It's not just atypical in contemporary American politics for people to be both ideological adversaries and close personal friends. It's atypical for contemporary American political figures to even be close personal friends with each other. Justices Scalia and Ginsburg showed just how much everyone else was missing. That won't be as significant to Scalia's legacy as his jurisprudence, but maybe it should.

VIDEO: President Obama on the passing of Justice Scalia