Monroe H. Freedman, a former law professor at George Washington University, was considered an authority on legal ethics — and a controversial one. (Gerald Martineau/The Washington Post)

Monroe H. Freedman, a law professor who was often credited with establishing the academic field of legal ethics, and whose controversial views once led a future chief justice to call for his disbarment, died Feb. 26 at his home in New York City. He was 86.

The cause was chronic lymphocytic lymphoma, said a granddaughter, Rebeca Izquierdo Lodhi.

Mr. Freedman became a nationally renowned expert on civil liberties while serving as a law professor at George Washington University from 1958 to 1973 and later at Hofstra University in Hempstead, N.Y.

He became even better known for his contributions to the emerging field of ethics, in which he addressed the sometimes conflicting responsibilities of a lawyer toward clients and toward the court.

“He was a towering figure in the legal academy and especially in legal ethics,” Georgetown University law professor Abbe Smith, who taught alongside Mr. Freedman and published books with him, said in an interview. “He was universally regarded as the founder of modern legal ethics as an academic field.”

Mr. Freedman wrote textbooks on the subject, and his landmark 1966 article, “The Three Hardest Questions,” remains a mainstay of the study of legal ethics to this day.

The article, which appeared in the Michigan Law Review, outlined three central obligations that every defense lawyer is bound to uphold: understanding all the facts of a case; preserving the confidentiality of a client; and being candid and forthcoming to the court.

There are times, however, when these legal principles can be in conflict, producing what Mr. Freedman called a “trilemma.”

The trust between a lawyer and client, he argued, is a fundamental cornerstone of the legal system and is essential to discovering the truth. But what is the lawyer’s responsibility if a client says he will not testify honestly on the witness stand?

Which legal obligation is more important — confidentiality or candor?

Mr. Freedman suggested that a defense lawyer’s primary duty is to be his client’s best advocate. The judicial system, after all, rests on the presumption that defendants are innocent unless the prosecution can prove otherwise. A defense attorney’s first responsibility, in other words, is to maintain the confidence of his client’s private discussions, not to declare the client guilty.

Lawyers have wrestled with such thorny questions for centuries, Smith said, but until Mr. Freedman’s groundbreaking study, “no one sat down and thought about these things and wrote them out.”

Mr. Freedman’s views provoked considerable debate, and he was sometimes accused of encouraging defendants to commit perjury. When he was removed from an ethics panel at George Washington University in 1966, he said the move was engineered by Warren E. Burger, then a federal appeals court judge in Washington. Burger, who became chief justice of the United States in 1969, went so far as to call for Mr. Freedman to be disbarred.

“What Monroe was writing was widely misunderstood to be in favor of perjury,” Smith said. “I think he should be known as one of the founders of client-centered lawyering. That’s what our adversarial system is about — about giving the client his day in court.”

Monroe Henry Freedman was born April 10, 1928, in Mount Vernon, N.Y. His father was a businessman.

After serving in the Navy, Mr. Freedman received three degrees from Harvard University: a bachelor’s degree in 1951, a law degree in 1954 and a master’s degree in law in 1956.

While teaching at GWU’s law school in the early 1960s, Mr. Freedman chaired the American Civil Liberties Union of the Nation’s Capital, advised civil rights groups and was an early champion of women’s rights. He was the volunteer counsel to the Mattachine Society, one of the country’s first gay-rights organizations.

In addition to clashing with Burger and others in the legal world, Mr. Freedman sometimes adopted other unpopular stances. He participated in antiwar protests during the Vietnam War, raised questions about the fairness of federal juries and even challenged civil rights leaders to expand their views of liberty beyond the issue of race.

“When a man fights for civil rights only when he is directly involved,” he said in a speech at Howard University in 1963, “his real concern is himself, and not the Constitution, the Bill of Rights or his fellow man. Negro civil-rights leaders, like everyone else, should be civil libertarians, regardless of race or color.”

In 1973, Mr. Freedman became the law school dean at Hofstra, only to resign four years later in a dispute with the university’s leadership. He remained on the faculty, however, and lectured widely throughout the country. He was the first executive director of the U.S. Holocaust Memorial Council, from 1980 to 1982.

From 2007 to 2012, he was a visiting professor at Georgetown University, where he and Smith taught a popular course in legal ethics. They published two books together, including “How Can You Represent Those People?” (2013).

Mr. Freedman’s wife since 1950, economist Audrey Willock Freedman, died in 1998. A son, Caleb Freedman, died in 1998; a daughter, Sarah Freedman-Izquierdo, died in 2014.

Survivors include two children, Alice Korngold and Judah Freedman, both of New York; a brother; a sister; seven grandchildren; and three great-grandchildren.

Mr. Freedman was willing to question authority at any level, including the quasi-mythic. In Legal Times magazine and the Alabama Law Review, he suggested that Atticus Finch — the upright lawyer in the fictional town of Maycomb, Ala., in Harper Lee’s “To Kill a Mockingbird” — was hardly a paragon of moral or legal virtue.

He noted that Finch defended Tom Robinson, a falsely accused African American, only after he was assigned to do so by a judge.

“Here is a man,” Mr. Freedman wrote, “who does not voluntarily use his legal training and skills — not once, ever — to make the slightest change in the pervasive social injustice of his own town.”

Mr. Freedman was widely assailed for criticizing Finch, but he didn’t back down. Basic “principles of right and wrong” have been obvious since the beginning of time, he wrote: “The apartheid that Atticus Finch practiced every day of his life — those things are wrong today, and they were wrong in Maycomb, Alabama, in the 1930s.”