Lewis worked for 32 years as a columnist for the Times, taking up such causes as free speech, human rights and constitutional law. He won his first Pulitzer in 1955 as a reporter defending a Navy civilian falsely accused of being a communist sympathizer, and he won again in 1963 for reporting on the Supreme Court.
His acclaimed 1964 book, "Gideon's Trumpet," told the story of a petty thief whose fight for legal representation led to a landmark Supreme Court decision.
Lewis saw himself as a defender of decency, respect for law and reason against a tide of religious fundamentalism and extreme nationalism. His columns railed against the Vietnam War, Watergate, apartheid in South Africa and Israeli settlements in the West Bank and Gaza.
He wrote his final "Abroad at Home" column for The Times on Dec. 15, 2001, warning against the United States fearfully surrendering its civil liberties in the wake of the terrorist attacks three months earlier.
"The hard question is whether our commitment to law will survive the new sense of vulnerability that is with us all after Sept. 11," he wrote. "It is easy to tolerate dissent when we feel safe." Gail Collins, then the editorial page editor of the Times, said when Lewis resigned that he had been an inspiration.
"His fearlessness, the clarity of his writing and his commitment to human rights and civil liberties are legendary," Collins said. "And he's also one of the kindest people I have ever known." "Gideon's Trumpet" became a legal classic, telling the story of Clarence Earl Gideon, whose case resulted in the creation of the public defender systems across the nation. In Gideon v. Wainwright, the high court ruled that criminal defendants are entitled to a lawyer even if they cannot afford one.
Gideon's victory, Lewis wrote, "shows that even the poorest and least powerful of men -- a convict with not even a friend to visit him in prison -- can take his cause to the highest court in the land and bring about a fundamental change in the law." The best-selling book was later made into a television movie starring Henry Fonda.
"Generation after generation of students, the way they learned about the Supreme Court, was by reading 'Gideon's Trumpet,' " said Ronald K.L. Collins, a scholar at the University of Washington School of Law who put together a bibliography of Lewis' expansive writings on free speech.
Lewis was known for his skill at interpreting and writing clearly about the decisions of the Supreme Court led by Chief Justice Earl Warren in the 1950s and '60s.
"One cannot talk about the Warren court without talking about Anthony Lewis," Collins said.
Lewis joined the Times in 1948 and spent most of his career there, except a stint at the now-defunct Washington Daily News, where he worked from 1952 to 1955.
He was chief of the newspaper's London bureau from 1965 to 1972.