By Ron Powers

Free Press. 723 pp. $35

For someone who made such an enormous contribution to American literature, Mark Twain has been the subject of many books but few major biographies. Albert Bigelow Paine's dated but still valuable three-volume Mark Twain: A Biography (1912) was the only "authorized" one. Paine, Twain's literary executor, also cobbled together an autobiography in 1920 that must be approached cautiously. The best biography remains Justin Kaplan's magisterial Mr. Clemens and Mark Twain (1966). Now Ron Powers -- the author of Dangerous Water: A Biography of the Boy Who Became Mark Twain and the Shelby Foote of Ken Burns's 2002 Twain documentary -- has published Mark Twain: A Life, after 20 years of research.

Powers, like other recent biographers, challenges Kaplan and his Pulitzer Prize-winning book. He accuses anyone who dares interpret Twain "through the prism of Freudian psychoanalysis" of treating the man "as an interesting, if not terribly self-aware outpatient -- a walking case-book of neuroses, unconscious tendencies, masks, and alternate identities." Powers's purpose is to restore "the contours of an actual, textured human character," as well as "his voice, not to mention his humor" that "has gone missing from many of these analyses."

He relies on great chunks of Twain, mostly from letters and notebooks, that might have been more felicitously woven into the fabric of his narrative. Nevertheless, the vitality in these quotes invigorates the book.

Powers recounts again the famous story of the poor river-town boy who became, according to his friend William Dean Howells, "the Lincoln of our literature." Twain's literary reputation was what he and Robert Louis Stevenson called "submerged renown," one that was "down in the deep water; once a favorite there, always a favorite; once beloved, always beloved; once respected, always respected, honored, and believed in." Although he received honorary doctorates from Yale, Oxford and elsewhere, Twain never felt that he was taken seriously. "The world likes humor, but it treats it patronizingly," E.B. White observed. "It decorates its serious writers with laurel, and its wags with Brussels sprouts." Sully Prudhomme, Bjornstjerne Bjornson, Christian Theodor Mommsen and Selma Lagerlof all won the Nobel Prize for Literature, but not Twain. (Neither did Tolstoy, Proust nor Joyce.) Twain's work had to wait until the 1935 centenary of his birth for the lavish critical attention that he believed it deserved. He always had the public's attention.

As a Hannibal, Mo., native, Powers might have brought more insight into the town's most famous son. A firmer editorial hand might also have pruned away some of the flippancy, the repetitions and slang, as well as some of the factual leaps. How, for instance. does Powers know that Sam Clemens studied McGuffey's Readers, the famous 19th-century schoolbooks? Twain later recalled several other textbooks by name, as well as the Sunday school tracts he loathed, but nothing from William H. McGuffey. Louisa May Alcott may have shown up in McGuffey's Fourth Reader, but not when Clemens was a boy. (She was only three years older than him.) Powers makes other mistakes, too: Horatio Alger did not write the first American boys' adventure books; the Currier & Ives fortune came from stone lithography, not photo engraving; and the actress with whom Twain hobnobbed was Ellen (not Eileen) Terry.

At times, this biography resembles, as Powers calls The Innocents Abroad, "a grab bag of abrupt digression." Powers is best when he sticks to the specific details of Twain's long, troubled life. He is particularly good at reconstructing the courtship of Clemens and his future wife, Olivia Langdon. He skillfully retraces the complex publishing history of Twain's books, including the founding and failure of his own firm, which led to his bankruptcy. But Powers goes off-track with gratuitous information. For example, he discusses at length the most notorious hookers in Virginia City and Twain's brief acquaintance with the forgotten actress Ada Isaacs Mencken ("the spiritual godmother of Marilyn Monroe, Gypsy Rose Lee, and Madonna"). References to Frank Sinatra, Helen Gurley Brown, Starbucks, Groucho Marx and Margaret Dumont -- even the heavy-metal group Metallica -- seem similarly irrelevant. Twain led a wild and untidy life that demands a strong, steady guide to shape it into a coherent biography, but Powers tends to meander along with his subject's violently shifting moods.

Sadly, Powers's literary judgments are not always sound. His enthusiasm is admirable, but he goes overboard on the merits of the ribald burlesque "1601" ("a hysterical underground masterpiece") and presumptuously calls Huckleberry Finn "the first great jazz composition in American literature." Treating Twain at one point as America's Shakespeare and then as its first rock star diminishes Powers's credibility as a biographer, as well as Twain's enormous impact on his era. That largely self-educated Missouri boy, with all his faults, became the authentic voice of America, with all its faults, and he has never been silenced. Mark Twain: A Life is not the last word, but as long as Twain does the talking, it says a lot. *

Michael Patrick Hearn's many books include "The Annotated Huckleberry Finn." His latest is "From Silver to Steel: Russian Children's Book Illustration 1899-1939."