BOOK REVIEW / BIOGRAPHY : Shedding Light on the Dark Side of a Celebrated Author : REMEMBER LAUGHTER: A Life of James Thurber <i> by Neil A. Grauer</i> ; University of Nebraska Press $20, 255 pages

Timed to coincide with the 100th anniversary of James Thurber’s birth, “Remember Laughter,” a succinct biography, is a gift package of mixed messages. Drawing heavily on the memories of friends, New Yorker colleagues and particularly Thurber’s daughter Rosemary, the book balances an admiring assessment of the delightful wit, the unforgettable drawings and the enduring classics against disturbing recollections of Thurber’s mercurial personality.

The result is an ambivalent biography that verges upon the revisionist when discussing the man himself while remaining respectful about most of his work. Still, by the time you have finished Neil A. Grauer’s book, you may find yourself not only deconstructing the stories but also regarding the cartoons from a new perspective. There was a dark side to Thurber, and what once appeared altogether whimsical and beguiling becomes ominous and far more complex than it seemed at first glance.

Thurber thought of his work as tragicomedy, believing that “humor and pathos, tears and laughter are, in the highest expression of the human character and achievement, inseparable.” Like many other humorists, he longed to be taken seriously and often deplored the fact that humorous writing tends to be ephemeral while pomposity and pretension endure.

As Grauer points out, Thurber’s fantasy “was not always a sanctuary for the soul; sometimes it served as an exterminator. In “The Whip-poor will,” “A Friend to Alexander” and other stories, fantasy kills. And Walter Mitty’s final daydream is of his own execution.

Although Thurber had been celebrated in England, where his quirky humor found instant acceptance, “The Years With Ross” was not received with pleasure by the British critics. Dame Rebecca West was particularly affronted, remarking that “buffoonery was in the eye of the beholder.”

When “The Years With Ross” appeared in the late 1950s, Thurber’s personality had already begun to show disturbing signs of change. After he was awarded several honorary degrees and a number of literary accolades, Thurber became so convinced of his own importance that he told literary critic Edmund Wilson he thought he deserved the Nobel Prize. By then, he was drinking excessively, talking compulsively and boring even his most ardent admirers with endlessly repeated anecdotes.

“He was a tortured man, no doubt about it,” his New Yorker editor, Roger Angell, says. By 1960, Thurber’s always poor vision had deteriorated badly, his quixotic wit had soured into wide-ranging anger, and his general health was poor. Increasingly frequent drinking bouts only exacerbated his depression, and many of his friends believed that the mental and physical decline was irreversible.

Happily, they were wrong, if only temporarily. Haila Stoddard, a well-known actress and loyal fan, had the delightful idea of adapting her favorite Thurber pieces for the stage. The result was “The Thurber Carnival,” a succes d’estime though not a box-office smash to match Thurber’s earlier play, “The Male Animal.”

The respite from anguish was pathetically short-lived. Within a few months of the show’s closing, Thurber suffered a cerebral hemorrhage, the first of many. The mood swings became more exaggerated, and his behavior grew increasingly abusive.

Although he continued to write, the magic light touch was gone, replaced by tedious word games, curmudgeonly attacks on virtually everything, and ponderous attempts at satire. The New Yorker rejected these late efforts, and Thurber became convinced that he was the victim of a conspiracy. Elliott Nugent, his collaborator on “The Male Animal,” remembers Thurber telling him that “people are not funny; they are vicious and horrible--and so is life.”

But for the three decades before blindness and ill-health embittered him, Thurber enchanted millions. Their children and grandchildren still delight in his fables and stories --”The 13 Clocks,” “The Wonderful O,” “The Last Flower” and “Many Moons.” Walter Mitty dreams on, as much a part of our heritage as Huckleberry Finn and Tom Sawyer, and even the captions for the cartoons have entered the vernacular, guaranteeing Thurber the lasting fame he thought had eluded him.