By Jill Laster

Charles Muscatine, a renowned Chaucer scholar who was fired by the University of California at Berkeley in 1950 for refusing to sign a loyalty oath, has died at age 89.

Mr. Muscatine, a professor and a champion of undergraduate-curriculum reform, died March 12 in Oakland of a lung infection.

His 1957 work, Chaucer and the French Tradition, is still considered one of the hallmarks in his field. "Before Charles, people tended to talk about the themes and ideas of Chaucer's poetry or the humor or whatever, but he really emphasized the poetic craft," said C. David Benson, a former student of Mr. Muscatine's, now a professor of English and medieval studies at the University of Connecticut.

Mr. Muscatine received his undergraduate, master's, and doctoral degrees from Yale University and served in the U.S. Navy during World War II. He took part in the D-Day landing at Omaha Beach. In 1948 he joined Berkeley's English department as a specialist in medieval literature. The next year, with the nation gripped by anti-Communist sentiment, Berkeley began requiring faculty members to sign loyalty oaths to the California Constitution and deny affiliation with any organization calling for the overthrow of the U.S. government.

Mr. Muscatine, an assistant professor at the time, and 30 other faculty members refused to sign and were fired in the summer of 1950.

"My main feeling about it had to do with its feeling to me totally unconstitutional, un-American," Mr. Muscatine said in a 2000 interview kept by Berkeley's University History Series at the Regional Oral History Office. "I was and maybe still am very idealistic about the role of professors in society, and so it just seemed to me to be an insult to the gown."

He came back to Berkeley in 1954, after the Supreme Court of California declared the oath unconstitutional, and became a full professor in 1960.

Mr. Muscatine was a strong advocate for students' academic freedom during the Berkeley Free Speech Movement, from 1964 to 1966.

Friends and colleagues described him as someone with an unending commitment to his students' personal and academic growth. He was the lead author, in 1966, of what became known as the Muscatine Report, which called for small, student-led courses and emphasized the need to strengthen undergraduate education at a research university.

University officials chose not to follow the recommendations in his report, so in 1974, Mr. Muscatine and two fellow professors started Strawberry Creek College, officially the Collegiate Seminar Program. The program, which lasted for six years, pushed graduate students and professors to create small classes for lower-division students.

Berkeley has since reduced class size and focused more on undergraduate education, "and Muscatine was really at the forefront of the campaign to emphasize those kinds of issues," said Richard Hutson, a professor emeritus of English at Berkeley.

Michaela Paasche Grudin, a professor emerita of English at Lewis & Clark College, said Mr. Muscatine, who retired in 1991, always took a strong personal interest in students, inviting them to dinner or taking them on skiing trips. Ms. Grudin, one of his former students, developed a lifelong friendship with Mr. Muscatine, who she says was interested in her family as well as in her scholarly work.

As a professor, Mr. Muscatine taught freshman-level composition courses because "it was in those courses you could really change a person's whole attitude, not only about their studies but about life," Ms. Grudin said. In the last year of Mr. Muscatine's life, she said, he met regularly with a man who had only a middle-school education for tutoring sessions at the library.

"People would call him from all walks of life and all ages, and more than anyone I knew, it was young people who were still very interested in being with him," Ms. Grudin said.

Mr. Benson called his former professor "the least pompous famous person I've ever known," excited both about scholarship and his students. Other friends recalled Mr. Muscatine's warmth and quick wit.

His daughter, Lissa Muscatine, chief speechwriter for Secretary of State Hillary Rodham Clinton, said that while her father held high academic standards for his children, he maintained a kind demeanor and a sense of humor, which endeared him to many people.

"Students were influenced by him, scholars were influenced by him, political advocates were influenced by him—and that certainly comes through in all the e-mails and letters that I've gotten," she said. What also comes through is "this overwhelming affection for him," she added.

A memorial service for Mr. Muscatine is being planned.