(FORTUNE Magazine) – Before Stephen Covey had formed even one habit, a still greater motivator had penned a magnum opus. Think & Grow Rich, by Napoleon Hill, appeared in 1937 and has never since been out of print. With over ten million copies sold, it qualifies as the best-selling business/self-improvement title of all time. Yet no one has told the story of its authorship--no one, that is, until Hill's associate Michael Ritt and writer Kirk Landers in their iconoclastic book, A Lifetime of Riches: The Biography of Napoleon Hill (Dutton, $24.95).

Hill himself gave a bowdlerized account of his book's origin: He claimed that when working as a 25-year-old reporter in 1908, he was sent to interview Andrew Carnegie. The steel magnate turned the tables on Hill, asking him questions that have intrigued self-helpers ever since: Might not the lives of great men be connected by a common thread? Might not Ford, Edison, Firestone, Bell, and others share certain winning habits? And could these, perhaps, be synthesized into a science that anybody with gumption could learn?

Carnegie challenged Hill to undertake such a study, offering him letters of introduction to the famous. Three decades later, out popped Hill's findings: Think & Grow Rich.

What happened in the interim? Did Hill himself think and grow rich--or just thoughtful? Personal details matter. Nobody, after all, is going to believe How to Win a Bullfight once he discovers the author got gored in nine matches out of ten. Hill maintained that business success and domestic bliss awaited anyone whose purpose was definite, whose plan was clear, whose personality was pleasing, and whose persistence was adamant.

Fans who want to preserve their good opinion of him should therefor think extra thoughtfully before opening A Lifetime of Riches. It's not just the book's florid, often melodramatic style. The authors depict a man whose genius, most of the time, was for failure, who left behind a string of broken businesses, and who treated his first wife and their children shabbily.

No one ever sought success more desperately than Hill. In an attempt to make a living while writing his book, he floated some 30 ventures--all grandiose, almost all doomed. His most inspired? A scheme called the Intra-Wall Institute, which peddled correspondence courses to the incarcerated. Financial security eluded him until he was well into his 60s. All the while, he lectured on success.

His personal relations fared no better. Associates found him boastful, pompous, sharp-tongued. Yet in his own mind he was never at fault. Always it was "enemies," "jealous associates," or "gangsters" who thwarted him. At 42 and broke, he decided in 1925 that he had finally "hit bottom"--which, in Hillspeak, meant he considered getting an ordinary job.

Had he done so, the news would have been just so much nectar to his first wife, Florence. She married him in 1910, little dreaming he would postpone their honeymoon until 1919 (for financial reasons, he said), pawn her engagement ring, borrow her money, live in fine hotels while she lived with relatives, or sire a son born entirely without ears.

None of these unhappy discoveries can change the fact that millions of readers continue to draw inspiration from Think & Grow Rich. Its appeal is evergreen, and Hill, before he died in 1970 at age 87 (net worth: about $1 million), claimed that by writing it he had made more millionaires than Carnegie. But then, he claimed a lot of things.

He claimed to have been an attorney, and wasn't. He claimed to have helped President Wilson negotiate Germany's surrender in the First World War and to have helped F.D.R. pen fireside chats. The proof? Lacking. Charges of fraud hounded Hill at least twice during his career. In light of these facts, it would be nice to say with complete certainty that he really did interview Ford, Bell, Edison, Rockefeller, Luther Burbank, and all the rest. Where are the notes? Nowhere to be found. They were destroyed, said Hill, in a tragic warehouse fire.

-- Alan Farnham