Frederick Crews, a literary critic and a leading skeptic in the contentious scholarly debate over the achievements and legacy of Sigmund Freud, died on Friday in Oakland, Calif. He was 91.

His wife, Elizabeth Crews, on Monday confirmed the death.

Mr. Crews, a professor emeritus of English at the University of California, Berkeley, was the author of more than a dozen books. Most recently, he wrote “Freud: The Making of an Illusion,” a deeply researched evisceration of Freud’s reputation and therapeutic insights that drew wide critical attention when it came out in 2017.

He was a longtime contributor to The New York Review of Books, where his essays and reviews explored the works Melville, Twain and Flannery O’Connor, among other authors. He also examined broader subjects like recovered memory therapy, the Rorschach test, alien abduction cases and, particularly, psychoanalysis, which he considered a pseudoscience, as well as the scourge of what he called Freudolatry.

As a young professor at Berkeley, Mr. Crews made a splash in 1963 with “The Pooh Perplex,” a best-selling collection of satirical essays lampooning popular schools of literary criticism of the time; they carried titles like “A Bourgeois Writer’s Proletarian Fables” and “A.A. Milne’s Honey-Balloon-Pit-Gun-Tail-Bathtubcomplex.”

Writing in The New York Times Book Review, Gerald Gardner called it a “virtuoso performance” and “a withering attack on the pretensions and excesses of academic criticism.” (In 2001, Professor Crews published “Postmodern Pooh,” a fresh takedown of lit-crit theories.)

Professor Crews regarded himself as “a scientifically chastened ex-Freudian,” as he put it in a letter to the science journalist John Horgan. He began his career with “a good deal of faith in the Freudian description of the human mind,” he explained in a 1999 interview with PBS NewsHour. Several early works, including a 1966 critical study, “The Sins of the Fathers: Hawthorne’s Psychological Themes,” focused on Freudian analysis of classic literary texts.

But he gradually began to question the merits of Freudian theory, revealing his skepticism in a 1975 essay collection, “Out of My System: Psychoanalysis, Ideology, and Critical Method.” He brought it into full light in later works, notably a 1986 essay collection, “Skeptical Engagements,” and a long essay in The New York Review of Books in 1993 titled “The Unknown Freud.”

Essentially, Professor Crews came to regard Freud as a charlatan. In a debate with the psychoanalyst and author Susie Orbach in 2017, published in The Guardian, he maintained that Freud had “contradicted, discomfited and harangued his patients in the hope of breaking their ‘resistance’ to ideas of his own — ideas that he presumptuously declared to be lurking within the patients’ own unconscious minds.” In the process, he said, Freud created a myth about himself and his findings that failed to live up to empirical scrutiny.

His polemical broadsides vaulted him to the forefront of a group of revisionist skeptics loosely known as the Freud bashers.

“Freud: The Making of an Illusion” was his most ambitious attempt to debunk the myth of Freud as a pioneering genius, drawing on decades of research in scrutinizing Freud’s early career. Writing in The New York Times Book Review in 2017, George Prochnik found the book to be provocative if exhaustingly relentless: “Here we have Freud the liar, cheat, incestuous child molester, woman hater, money-worshiper, chronic plagiarizer and all-around nasty nut job. This Freud doesn’t really develop, he just builds a rap sheet.”

Frederick Campbell Crews was born on Feb. 20, 1933, in Philadelphia to Maurice and Ruby (Gaudet) Crews. His father was a patent lawyer.

Frederick attended Yale University and received his Ph.D. from Princeton in 1958 with a dissertation on E.M. Forster. He joined the faculty at Berkeley in 1958 and taught there until his retirement in 1994. In the mid-1960s, he became involved in the antiwar movement, serving as a co-chairman of Berkeley’s Faculty Peace Committee, “but when even moderate Republicans joined the antiwar cause around 1970, I felt that my activism wasn’t needed anymore,” he told an interviewer in 2006.

In addition to his essays and critical works, Professor Crews wrote “The Random House Handbook,” a popular composition and style manual first published in 1974, and edited several anthologies and style guides. He was a member of the American Academy of Arts and Sciences.

He married Elizabeth Peterson, a photographer who is known as Betty, in 1959. In addition to her, he is survived by a sister, Frances James; two daughters, Gretchen Detre and Ingrid Crews; four grandchildren; and one great-granddaughter. He and his wife had lived in Berkeley for many decades.

Professor Crews started writing for The New York Review of Books in 1964, beginning with a review of three works of fiction, including a story collection by John Cheever. His essays over the decades covered a lot of territory, literary and otherwise, and while his writing was invariably erudite and carefully argued, it was often mercurial, by turns sarcastic, penetrating, acerbic and witty.

One unlikely cause that he devoted himself to in recent years was to assert the innocence of Jerry Sandusky, the former Penn State assistant football coach who was convicted in 2012 of sexually abusing young boys and is now in prison.

“I joined the small group of skeptics who have concluded that America’s paramount sexual villain is nothing of the sort,” Professor Crews wrote in one article in 2021, adding, “believe it or not, there isn’t a shred of credible evidence that he ever molested anyone.”

Professor Crews linked the charges against Mr. Sandusky to another of his notable targets, the recovered memory movement, which took hold in the 1990s and which he saw as stemming from the excesses of psychoanalytic theory. His two-part essay, “The Revenge of the Repressed,” which appeared in 1994, was included in his collection “Follies of the Wise,” a finalist for the 2006 National Book Critics Circle Award.

“Thanks to the ministrations of therapists who believe that a whole range of adult symptoms can probably be best explained by the repression of childhood sexual abuse,” he wrote in The Times in 1997, “these people emerge from therapy drastically alienated not only from their families but also from their own selves. In all but the tiniest minority of cases, these accusations are false.”

Professor Crews’s work “was and remains an invaluable weapon, wielded on behalf of sanity and science, against the forces of ignorance, self-interest and moral panic,” Carol Tavris, a social psychologist and another longtime critic of recovered memory therapy, said in an email.

His recovered memory essay prompted a series of no-holds-barred exchanges with readers that spilled over into multiple issues of the magazine. Professor Crews was often at his most full-throated in The Review’s letters to the editor column, where intellectual debates can border on trench warfare.

He proved to be a merciless adversary over the decades, especially for Freud supporters, and in the process helped elevate the letters column into something of an art form.

In 1965, in his first response to a letter in The Review, he crossed swords with the writer Elizabeth Hardwick, who objected to the “patronizing tone” of his review of an essay collection by Edmund Wilson. “Elizabeth Hardwick’s letter rests on such a crude misconstruction of my printed statements, to say nothing of my imagined political loyalties, that I see nothing to be gained from quarreling with her,” he wrote. “Perhaps she might simply reread my essay — unhysterically.”

Professor Crews was rarely that succinct. Another review of several books on U.F.O.s and alien abduction in 1998 set off an exchange with four readers that, at almost 5,000 words, was just as lively as the original review.

Despite his long crusade against Freud, Professor Crews recognized the vast cultural impact of psychoanalysis. “No one disputes the enormous extent of Freud’s influence,” he said in the 2017 debate with Dr. Orbach. “The question before us is whether we ought, on balance, to be grateful for it.”

The poet Robert Pinsky, a former Berkeley colleague, recalled Professor Crews as “a kind, funny man whose love of a good fight never diluted the kindness or the ability to laugh at anything — including himself.

“One of his great pleasures in life was skepticism,” Professor Pinsky said. “With vivid glee, he told me about recataloging and organizing the library in the summer camp where he was tennis instructor. That athletic, intellectual young man took pleasure in cataloging the Bible under fiction.”

Alex Traub contributed reporting.