THE KNOW-IT-ALL

One Man's Humble Quest to Become the Smartest Person in the World

By A.J. Jacobs.

Simon & Schuster. 386 pp. $25

When the first volume of the Encyclopedie was issued in the summer of 1751, many in the clergy and laity spurned it as they would the Devil's Bible. They reviled it as detrimental to the authority of church and king. Chiefly edited by Denis Diderot, the Encyclopedie championed Enlightenment ideals, such as reason and skeptical inquiry. In 1768, the Encyclopaedia Britannica followed suit with another less-than-magnificent launch. (In comparison with the 17 text volumes of the Encyclopedie, the first edition of Britannica eventually came in at three, with the first two devoted to the letters A and B, respectively.) Though perusing an encyclopedia has lost its rebellious chic, the suspicion that greets the consumption of facts hangs on. For as A.J. Jacobs highlights in his charming memoir about reading the Britannica -- and as Diderot's critics surely thought -- the quest for knowledge is seldom free of ulterior motives.

Midway through his thirties, Jacobs found himself lost in the woods of pop culture. A former writer for Entertainment Weekly who'd migrated to the editorial department of Esquire, Jacobs, by his own reckoning, had shed the intellectual leanings of his youth. While attending the Dalton School in New York, he grew enamored of the idea that he was "the smartest boy in the world" -- until life intervened in the form of a documentary on young Hasidic Jews. Upon learning that these boys, who were around the same age as he, studied 16 hours a day, his bubble burst, but not his vanity. Growing up as the son of a well-to-do attorney, Jacobs did not lack for an inferiority complex. Jacobs Sr. emerges in these pages as the benevolent rival and prankster from whom his son inherited the task of reading Britannica from A to Z.

As befits a know-it-all, Jacobs begins his book with a potentially annoying admission. A graduate of Brown University, Jacobs confesses that he hasn't "accomplished anything particularly impressive . . . unless you count my childhood collection of airsickness bags from every major airline." This from a man with a three-bedroom apartment on the Upper West Side who's been known to receive complimentary bottles of wine because of his day job. Of course making others eager to compare notes is a cherished ploy in the know-it-all's playbook. But perhaps his idea of what constitutes true accomplishment is more on track than what normally wins cool points, particularly when one considers such past beacons as Louis Braille, who "developed his writing system for the blind at age 15," or Isaac Asimov, who wrote some 500 books.

Jacobs Sr. abandoned his quest somewhere in the B's, but his son follows through. Organized alphabetically, "The Know-It-All" recounts his trek through the encyclopedia and its repercussions throughout his life. With a high quotient of humor, readers are showered with information on, among other things, the origins of canned laughter, the varieties of grease and tidbits about the famous -- e.g., in the 16th century, Ben Jonson eluded a murder rap by pleading that his knowledge of Latin entitled him to sacerdotal immunity; George Bernard Shaw once posed nude for an art photographer; it was a rusk biscuit and not a madeleine that prompted Proust's memories. Apart from Jacobs's selection of choice trivia culled from Britannica's 33,000 pages, it's his mapping of the abuses of knowledge that deserves mention.

In his struggle to keep pace with his cerebral family, Jacobs is made aware of how knowledge is used in the least disinterested ways. While the accomplishments of his father -- eminent within his field of jurisprudence, author of 24 books and record holder for the most footnotes in a legal article (4,824) -- are a silent goad, his brother-in-law Eric Schoenberg is the one with whom the writer conspicuously dukes it out. While Jacobs Sr. enjoys playing the fool, Eric, a high-flying career jumper, digs asserting his bona fides. From tennis to dropping perfect bons mots at dinner, he bests Jacobs and makes him feel like a dolt.

The qualities one finds especially nettlesome in others are often those that lie in oneself. Like Eric, Jacobs has a difficult time resisting the urge to preen. After slipping into Mensa on his SAT scores, he is stricken with the anxiety of a new transfer student. During a trivia contest at a Mensa meeting, he drapes unflattering attention on himself; fearing that his knowledge will go unrecognized, he bellows that Abelard is "AN 11TH-CENTURY CHRISTIAN THEOLOGIAN!" Bet you won't forget that.

Deprived of the friction that arises from personal interaction, it's a cinch to accommodate Jacobs's showiness. Prose allows him to rub in his Britannica knowledge with a skill that's often absent in his life. (One's apt to whistle in disbelief when his wife comes to him with a rash on her stomach and he likens it to "the Great Red Spot on the surface of Jupiter.") Fueled by candor, memoirs are an ideal forum for someone who wants to be appreciated, so it tidily works out that Jacobs's candor about his own catty behavior and the temptation to look smart is endearing. In his all-American effort to better himself, he hasn't renounced his love of entertainment. Plucked with care, the book's facts will provide enough anecdotes to perk up conversations and weather the season's social events. More substantially, "The Know-It-All" belongs to the category of literary expeditions whose chief reward is their nudging toward a fantastic, heretofore forbidding, work. One can daydream that Diderot would be pleased.