Are dissenting opinions vanity or dishonesty?

Tony Mauro has an interview with Supreme Court Justice Samuel Alito:

Alito ... commented on Roberts' efforts to achieve greater unanimity on the Court, even at the expense of making broad rulings. Alito thinks there is merit in the idea, and says Roberts has already "worked to prevent fractured opinions." But Alito says Roberts has not made the pitch for unanimity to the justices as a group. For his part, Alito says, "I don't feel too strongly about writing separate opinions."

But he says Roberts' campaign points up a problem that any appellate judge "struggles with," namely, how far to go in compromising in the interest of unanimity and giving clear guidance, without crossing the line into endorsing "something you don't believe in."

Alito recalled that in his early days as a judge on the 3rd Circuit, he heard a judge -- whose name he can't recall -- lecture on the evils of writing dissents. "He said it was nothing but vanity, and that it didn't achieve anything. That's one side of it."

Aw, come on, who was it?

The other side, which Alito worries about, is the dishonesty of signing onto an opinion with which you disagree.

"I think of the analogy of someone coming to your door and asking you to sign a petition," says Alito. "You say no, you don't agree with it, and the person at your door says, ‘Sign it anyway.'"

So, dissenting opinions: vanity or dishonesty? I think it's somewhere in between. It's not really dishonest to sign on even though you disagree. Once a majority of the Justices have one opinion, it will be the precedent in future cases, and you'll cite it and follow it then. What difference does it make if you start following it before it issues? Should you always do that then? Should we agree with the unnamed Third Circuit judge who said that dissenting opinions were nothing but vanity? I'd say that is going too far, but reading dissenting opinions, you can encounter a lot of unseemly preening. Still, there is an important place for dissent:

Justice William J. Brennan, Jr., published an article in the January 1986 Hastings Law Journal, “In Defense of Dissents,” confessing that when he first came to the U.S. Supreme Court, he did not write a single dissent, although 42 of the 56 opinions he authored in 1985 were just that. So why dissent?

After all, the law is made by those who command the majority, not the outsiders. Even Justice Oliver Wendell Holmes, the "Great Dissenter" at one point opined that dissents are generally "useless" and "undesirable." Justice Potter Stewart labeled dissents "subversive literature."

But by the time he wrote the article Justice Brennan was a true believer in the power of dissent. In this way flaws are demonstrated in the majority’s legal analysis, thereby laying the basis for future corrective action. And a dissent holds the majority accountable for the rationale and consequences of its decision. "At the heart of that function is the critical recognition that vigorous debate improves the final product by forcing the prevailing side to deal with the hardest questions urged by the losing side."

Too much antagonism toward dissent -- in judicial opinions and elsewhere -- betrays a fear that one's arguments are flawed. But that doesn't apply to what Chief Justice Roberts has talked about, which is simply narrowing the scope of the decision to the point where it can eliminate the disagreement.