We’re closing in on the fifth anniversary of the last time Supreme Court Justice Clarence Thomas asked a question during oral arguments. To mark the occasion, New York Times Supreme Court correspondent Adam Liptak looks at the legal debate Thomas’ silence has sparked:

He asked no questions, for instance, in a 2007 case about high school students’ First Amendment rights. In a concurrence, he said he would have overturned the key precedent to rule that “the Constitution does not afford students a right to free speech in public schools.”

Neither side had advanced that position. The basis for and implications of his concurrence were not explored at the arguments, because, by asking no questions, Justice Thomas did not tip his hand.

No other justice joined Justice Thomas’s opinion. “If Justice Thomas holds a strong view of the law in a case, he should offer it,” David A. Karp, a veteran journalist and third-year law student, wrote in the Florida Law Review in 2009. “Litigants could then counter it, or try to do so. It is not enough that Justice Thomas merely attend oral argument if he does not participate in argument meaningfully.”

During last’s year fourth anniversary celebration I noted that while Thomas’ silence on the bench may be regrettable, there’s no question he’s taking a very active part in the justices’ internal debates—and that, after all, is where the Court's decisions are ultimately made. As the legal journalist Jan Crawford Greenburg wrote in The Wall Street Journal in 2007:

An extensive documentary record shows that Justice Thomas has been a significant force in shaping the direction and decisions of the court for the past 15 years.

Immediately upon his arrival at the court, Justice Thomas was savaged by court-watchers as Antonin Scalia's dutiful apprentice, blindly following his mentor's lead. It's a grossly inaccurate portrayal, imbued with politically incorrect innuendo, as documents and notes from Justice Thomas's very first days on the court conclusively show. Far from being a Scalia lackey, the rookie jurist made clear to the other justices that he was willing to be the solo dissenter, sending a strong signal that he would not moderate his opinions for the sake of comity. By his second week on the bench, he was staking out bold positions in the private conferences where justices vote on cases. If either justice changed his mind to side with the other that year, it was Justice Scalia joining Justice Thomas, not the other way around.

For more on Thomas' jurisprudence, go here. To find out why Reason named him one of our “35 Heroes of Freedom,” go here.