As Mr. Lewis wrote in The New York Review of Books in 2005, the First Amendment is fundamentally a prohibition on government censorship. Asking more of it, he wrote, “does not fit easily within the main use of the amendment.”

Mr. Lewis said judges were in a better position to balance the interests involved, and he spoke approvingly of a concurring opinion by Judge David S. Tatel of the United States Court of Appeals for the District of Columbia Circuit in the decision that sent a Times reporter, Judith Miller, to jail for 85 days in 2005. Judge Tatel said a special prosecutor’s need for information outweighed the public interest in allowing Ms. Miller to protect her source.

Mr. Lewis was similarly skeptical about what he considered unwarranted press intrusions into privacy. In a 2002 article in The Nova Law Review, Mr. Lewis criticized The Times and other news organizations for filing briefs supporting reporting that he considered tawdry.

In his final book, “Freedom for the Thought That We Hate: A Biography of the First Amendment,” published in 2008, Mr. Lewis wrote that he was inclined to relax some of the most stringent First Amendment protections “in an age when words have inspired acts of mass murder and terrorism.” In particular, he said he might reconsider the conventional view that there was only one justification for making incitement a crime: the likelihood of imminent violence.

Mr. Lewis wrote that there was “genuinely dangerous” speech that did not meet the imminence requirement. “I think we should be able to punish speech that urges terrorist violence to an audience, some of whose members are ready to act on the urging,” Mr. Lewis wrote. “That is imminence enough.”

Much as he loved and admired the press, Mr. Lewis considered the courts to be the bedrock institution of American freedom.

“His lifelong faith in judges dominates his legal thinking,” Mr. Frankel said. “No matter how mistaken or craven” a court might be, he added, Mr. Lewis saw the judiciary “as the ultimate safeguard of our democracy.”