NEW YORK -- Justin Kaplan, an author and cultural historian with a taste for troublemaking who wrote a definitive, Pulitzer Prize-winning biography of Mark Twain and spiced the popular canon as general editor of Bartlett's Familiar Quotations, died Sunday night at age 88.

Kaplan had been suffering for years from Parkinson's disease, his wife, author Anne Bernays, said Tuesday. He died at Mount Auburn Hospital in Cambridge, Mass.

A longtime professor at Harvard University, Kaplan wrote several acclaimed biographies, notably "Mr. Clemens and Mark Twain." Released in 1966, it was immediately praised as a landmark in Twain scholarship, a stylish and acute account of the rowdy Missouri native and Western humorist who attempted, imperfectly, to fit in with the Eastern elite. Simply using Twain as a pen name, Kaplan observed, signified a life divided against itself.

"He was bound to be tormented by the distinction and the split, always invidious, between performing humorist and man of letters, and he had no way of reconciling the two," Kaplan wrote. "S.L. Clemens of Hartford dreaded to meet the obligations of Mark Twain, the travelling lecturer."

"Mr. Clemens and Mark Twain" won the National Book Award and the Pulitzer. It has been praised by such authors and Twain fans as E.L. Doctorow and Tom Wolfe and remains the standard for Twain biographers. Reviewing the book in The New York Times, Thomas Lask wrote that "Not in years has there been a biography in which the complexities of human character have been exposed with such perceptiveness, with such a grasp of their contradictory nature, with such ability to keep each strand clear and yet make it contribute to the overall fabric."

The book's effect was so strong, Lask concluded, that something of Twain's "ache of living has been rubbed off" on the reader, too.

Kaplan also wrote books about Walt Whitman and journalist Lincoln Steffens. His other works included a collaboration with Bernays, "The Language of Names," and, most recently, "When the Astors Owned New York."

In the 1980s, he was hired as general editor of Bartlett's Familiar Quotations, and, with something of Twain's spunk, set out to enliven what he believed a stuffy institution. He included quotes with four-letter words, noting that people wouldn't be able to talk without them. He added women and minorities, worked in rock lyrics and celebrities such as Jerry Seinfeld ("Everybody lies about sex. People lie during sex. If it weren't for lies, there'd be no sex") and even found room for children's television character Cookie Monster ("Me want cookie").

The most notable quote may have been from Kaplan, not in the book, but in a newspaper interview, when he acknowledged, "I'm not going to disguise the fact that I despise Ronald Reagan." Conservatives complained the new Bartlett's, published in 1993, contained only three quotes from the former president and omitted his famous Cold War command, "Mr. Gorbachev, tear down this wall."

Kaplan later agreed he was "carried away by prejudice" and included more Reagan quotes in the next edition, released in 2003.

The son of a successful shirt manufacturer, Kaplan was born in New York City in 1925. He was a gifted and avid student who advanced so quickly that he entered Harvard at age 16. He was fascinated by words and language and by his early 20s had edited translations of Plato and Aristotle.

He was an editor at Harry Abrams, an ambitious publisher of art books, when in 1953 he met Bernays, daughter of public relations pioneer Edward L. Bernays and writer Doris E. Fleischman and great niece of Sigmund Freud. In "Back Then," a joint memoir by Kaplan and Bernays released in 2002, the two referred to themselves as "children of privilege" who went to progressive schools and were "grounded in a classical approach to education -- a lot of memorizing and Shakespeare, an exhaustive approach to history, literature, and the sciences."

Kaplan and Bernays were married in 1954 (they eventually had three daughters) and soon after he was invited by Max Schuster, co-founder of Simon & Schuster, to help acquire "better books," to seek out younger authors and to "deal diplomatically" with such established names as Bertrand Russell and "Zorba the Greek" author Nikos Kazantzakis.

"It was fun to work at Simon & Schuster," Kaplan later wrote, "not surprising to see editors staying long after hours to talk books, trade industry gossip, and joke over office bottles of Scotch and gin. In the days before it was absorbed into a conglomerate the house was like a summer camp for intellectually hyperactive children."

But by the late 1950s, he had become more cynical. He recalled taking on a memoir by former Soviet ambassador Joseph E. Davies, author of the bestselling "Mission to Moscow." The book was essentially an embarrassing tribute to dictators the ambassador had known. When Davies died shortly before publication, Kaplan learned that his family had known he was mentally incompetent, but let him sign a deal anyway, wanting the money from his advance.

The final push came in 1959 when Kaplan saw Hal Holbrook's celebrated stage performance of Twain. Kaplan became fascinated with Twain, read everything he could by and about him and wrote a 10-page proposal, accepted by Simon & Schuster for a $5,000 advance. Needing distance from the "adrenaline-intoxicated style" of New York, he and his family moved to Cambridge, where he remained for the rest of his life.

In lieu of flowers, Bernays asked that donations be sent to the Michael J. Fox Foundation for Parkinson's Research.