John H. Mason, 58; was appellate judge

John Homans Mason, a seventh-generation direct descendant of Abigail and John Adams and a justice of the Massachusetts Appeals Court, was in many ways the quintessential Bostonian.

"He was unpretentious, tousled, effusively polite, and disarmingly friendly," Judge Rudolph Kass, a colleague and friend, said in a statement. "His gentleness was wholly genuine but it disguised an acute and penetrating intelligence, as well as a toughness of mind and spirit when the occasion demanded."

Judge Mason died July 17 of esophagus cancer at Massachusetts General Hospital. He was 58.

In the Appeals Court, Judge Mason earned a reputation for thoroughness, never leaving any record unexamined. His first law clerk, Erik Tennen, recalls spotting Judge Mason in the court clerk's office hours after it closed, searching for documents.

A first-rate craftsman, Judge Mason wrote opinions rich in detail that consistently marched to persuasive conclusions, Kass said.

"In the inner consultations of the court, his intuitive civility and generosity of spirit, even when in opposition, made him a valuable and even loved member of the court," Kass said.

Born in Boston on Oct. 24, 1945, Judge Mason grew up five blocks from the State House, with the Public Garden as his play area. After graduating from Harvard College with honors in 1967, he enlisted in the Army and volunteered for duty in Vietnam.

Family members recall him saying he had no right to stay home while his friends were being shot at.

During the war Judge Mason served as an adviser to Vietnamese combat troops. Although he objected to the way the war was being waged, he felt the nation should not abandon the cause.

"We started the war; we escalated it; and we can't walk away from the people we got into it," he would say, according to family members.

He was awarded the Bronze Star and a Vietnamese medal of similar rank.

After his honorable discharge from the Army, Judge Mason attended the University of Pennsylvania Law School, where he served as editor in chief of the Law Review and graduated with honors in 1973. He then worked as a clerk for Judge Walter R. Mansfield of the United States Court of Appeals for the Second Circuit.

Judge Mason began practicing law with the Boston firm of Ropes & Gray in 1974 and was promoted to partner in 1982. Specializing in labor and employment law, litigation, and civil rights, he headed prominent cases, including Hazen Paper Co. v. Biggins in the US Supreme Court, which involved a claim of age discrimination in employment.

He leaves his wife of 18 years, Barbara; his stepdaughter, Abby; and his sister, Abigail Browne. Funeral arrangements are pending.