n June 10, 1935, Robert Smith, a physician from Akron, Ohio, took his last drink. He and William Wilson, better known as Dr. Bob and Bill W., had no idea that the date would later mark the beginning of what some consider one of the most important movements in the 20th century: Alcoholics Anonymous. Wilson later wrote an account of their philosophy ó that only an alcoholic could help another alcoholic quit drinking ó and the lives of other alcoholics that is referred to as the Big Book, the movement's bible.

Now Sotheby's is planning to auction what it says is Wilson's master copy of the working draft of "Alcoholics Anonymous," the Big Book's disarmingly straightforward official title. Its value has been estimated by the auction house as $300,000 to $500,000. The sale, scheduled for Friday, has created excited speculation among collectors and scholars about who will buy it, and a debate about its value and rightful place.

Given the enormous impact of a book that in its fourth printing alone has reached more than 19 million people, some believe that Sotheby's is offering a priceless historical document. That status, some argue, means that it should be placed in an archive accessible to scholars and ordinary people rather than on the auction block.

"I think these things really belong to the fellowship of A.A.," said Eileen Giuliani, executive director of the Stepping Stones Foundation, which maintains the home and the documents of Wilson and his wife, Lois Wilson, as a museum in Bedford Hills, N.Y. "Documents like this belong in archives."

Bill Pittman, a historian who has written extensively about the history of A.A., said he, too, was concerned that the manuscript's sale would make it inaccessible to scholars. He said the Sotheby catalog incorrectly stated that Wilson's annotations were among the multitude of annotations on the typewritten manuscript. Mr. Pittman said he viewed the manuscript last year when the owner took it to a rare-book dealer.

But Selby Kiffer, a senior vice president at Sotheby's, said the manuscript did indeed contain Wilson's annotations. He said experts had spent weeks going through the 161-page manuscript, which contains thousands of annotations by many people.

In either case, the absence of Wilson's annotations does not reduce the document's value, said Mr. Pittman, the director of historical information at the Hazelden Foundation in Center City, Minn. Although Wilson was the primary author, there were many drafts and many comments from a wide variety of people involved in the project, he said. The book authorship is stated as "the story of how many thousands of men and women have recovered from alcoholism."

"It's the most important piece of A.A. history to be sold, ever," said Mr. Pittman, who worked for several years at the A.A. archive in New York City. He said the margin notes and last-minute changes before the master copy went off to the printer provided valuable insights into how the Big Book evolved. Still, he said, he thought the document was overpriced. "I think someone should buy it and give it back to A.A. and let researchers like myself look at it," Mr. Pittman said. "I don't want someone to buy it and sell each individual page."

Ms. Giuliani said, she too, thought the manuscript's price put it out of the reach of serious researchers and was out of line with what A.A. material usually cost.

In many ways the argument about Bill W.'s manuscript is familiar, occurring whenever price tags are attached to valuable historical items. The first edition of "Alcoholics Anonymous" was published in April 1939, and only the personal stories attached to the basic text have changed over the years.

The 1938 document being auctioned was consigned to Sotheby's by an A.A. member, Joseph B. (He asked that only the initial of his last name be used.) His aunt was also an A.A. member, who knew Wilson personally, he said, and she gave Mr. B. the manuscript back in 2001. The 1978 inscription on the manuscript is from Wilson's wife, who died in 1988, to a "Barry" (who some historians say is the writer Barry Leach, who wrote a biography of Lois Wilson).

Along with the manuscript, Sotheby's is offering a second-edition Big Book that Wilson inscribed in 1958 to "Grace," Mr. B.'s aunt, and four LP albums of A.A. lectures.

Mr. B. said his efforts to find interest in the document within Alcoholics Anonymous "ran into a lot of brick walls, a lot of dead ends." So, he said, he turned to Sotheby's to establish its provenance and find a buyer. "Not being a rich man, there was some money to be made, but that was not my main reason," Mr. B. said. "It's beyond words for me." As an alcoholic in recovery since 1976, he said that Wilson "saved my life." He found it thrilling, he added, to imagine Wilson cobbling together the Big Book. "I hope it ends up in a proper setting, an academic setting," he continued. "I think Sotheby's can provide that venue."

Early drafts of the Big Book went out to dozens of people, from alcoholics to psychologists, who sprinkled the margins with their ideas, feelings and experiences. As the manuscript being auctioned by Sotheby's shows, the book was a vigorous exercise in group-think, with a jumble of different handwriting crossing out words, circling phrases, excising passages.

The first chapter tells Bill W.'s story. Wilson was born in East Dorset, Vt., in 1895 and died of emphysema in 1971. He met Dr. Bob, the co-founder of A.A., during a 1935 business trip to Akron. Desperate for a drink, he contacted a local minister who put him in touch with Dr. Bob, a general practitioner and an alcoholic with a failing practice. The two talked for hours, and the idea of a fellowship of alcoholics helping alcoholics was born.

The Big Book was published four years later, but the first sales were slow. It took took off only after a March 1, 1941, article in The Saturday Evening Post about Alcoholics Anonymous and its "freed slaves of drink," as the writer Jack Alexander put it.

"What really matters for us is the final version of the Big Book,' which helped millions of people to recover," said Judit Santon, the archivist at the General Service Office of A.A. in New York City, home to the largest A.A. archive in the world with half a million pieces of personal correspondence and primary documentation.

Much of the interest in the manuscript has come from "traditional book and manuscript dealers," Mr. Kiffer of Sotheby's said. As far as anyone knows, he added, the highest price tag for a single A.A.-related item has been for first-edition copies of the Big Book, signed by Wilson, which have gone for as much as $25,000.

A thriving market exists for Alcoholics Anonymous items, in the same way that people collect Elvis Presley or Civil War memorabilia, said David C. Lewis, a physician and founder of the Center for Alcohol and Addiction Studies at Brown University. Social historians or any collector of Americana, as well as members of 12-step programs would also find the manuscript intriguing, Dr. Lewis said.

"It's basically priceless," he said of the document being sold by Sotheby's. Susan Cheever, the author of "My Name Is Bill" (Simon & Schuster, 2004), a biography of Wilson, agreed. "This is one of the 10 or 20 most important books written in the 20th century, probably the most important nonfiction book," she said. "This guy, with `Dr. Bob,' figured out how to save alcoholics. They changed the way we think about human nature."