Full disclosure: I was friends with Robert Stone for the last 15 years of his life. Long before I met him I was a great admirer of his fiction, especially his third novel, “A Flag for Sunrise.” Our paths crossed in Key West where we both spent winters. While the island still has a raffish reputation — a hangover from the time when Tom McGuane, Jim Harrison and Phil Caputo roistered around town — it had by 2000 settled into sedate middle age, and had become what novelist William Harrison puckishly referred to as a “matriarchal society,” as Alison Lurie, Annie Dillard, Ann Beattie and Judy Blume became the town’s more influential literary residents.

Bearded, baggy-eyed, habitually high on drugs or alcohol, Stone cut a curious figure at catered cocktail parties. He resembled an avatar of old Key West, a shrimper or deep-sea fisherman, a hell raiser temporarily ashore squandering his pay and his health. But he didn’t behave like an island brawler. His bruises and scars came from falling down or stumbling into plate glass doors, not from fighting. He seldom raised his voice — which was surprisingly patrician — and rarely cut short his autodidactic monologues. Although a college dropout with a GED high school degree, he possessed arcane knowledge of religion, art, literature and history. Stone’s most striking feature, however, was his hands — not big work-roughened mitts, but soft palms and the gentlest grip of any man I’ve ever met.

Because Stone knew I had been a friend of Graham Greene, whom he loathed, we danced around that subject. It was a shame, I thought, since Greene and Stone had so much in common — disorder and early sorrow, a weakness for drink and drugs, and an enduring interest in women, all tidily packaged in Catholic guilt.

In the biography “Child of Light,” Madison Smartt Bell captures every aspect of Stone’s contradictory nature, especially his work ethic. Each of Stone’s novels — from “Hall of Mirrors” (1966) through the National Book Award winning “Dog Soldiers” (1974) to his final book, “Death of the Black-Haired Girl” (2013) — was achieved despite the author’s crippling depressions, repeated bouts of ill health and unwise dependence on self-medication.

A prolific writer himself, with more than 20 books, including a biography of Haitian revolutionary leader Toussaint L’Ouverture, Bell was also a friend of Stone’s and occasionally a traveling companion. One of the best sections of this praiseworthy biography is the account of a trip he took with Stone to Haiti, along with one of Stone’s mistresses, who had to nursemaid the novelist when it appeared that he might die while traveling to a voodoo ritual.

Yet sympathetic as he is to his subject, Bell never softens his focus or smooths over Stone’s less admirable traits. A great deal of the credit for this candor goes to Stone’s partner, whom Michael Herr christened “the patron saint of writers’ wives.” Janice Stone served as her husband’s muse, first reader, typist, cook and caretaker, accountant, travel agent and life coach. Unlike so many literary marriages, theirs lasted 55 years, and after Stone’s death Janice remained her husband’s helpmate and his biographer’s enabler. Where other widows might protect a great man’s reputation (and perhaps their own financial interest) by destroying unflattering documents or restricting access to diaries and letters, Janice set nothing off the record. Along with accounts of Stone’s medications (recreational and otherwise), his stretches in rehab and his suicide attempt, Janice provided information about Stone’s sexual escapades and her own affairs, which he encouraged. They had married young, before the late 60s’ sexual liberation, and the Stones allowed each other astonishing leeway. Stone fathered a child with another woman, and even that didn’t alienate Janice.

Bell has a novelist’s gimlet eye for details, and the Stone archive offered him rich material. It revealed as much about the state of publishing in the 21st century as it did about Stone. By any objective standard, Stone was a successful author whose novels were critically acclaimed and received geometrically increasing advances. Paid $1,500 for his first novel, Stone finished his career with a million-dollar multi-book contract. As Bell reminisced in the New Yorker, “Stone’s life could be read as a fulfillment of the American dream of which his work was so critical.”

But he never escaped the damage he suffered during his Dickensian childhood. Raised by an unmarried schizophrenic mother in a series of squalid hotel rooms, Stone was never told anything more about his father than his mother’s unreliable report that the man was “a Greek, a Jew, or a Lebanese.” (A DNA test contained no information to support his mother’s claims.) When his mother became unfit to care for him, Stone was consigned for four years to a Catholic orphanage where the faith was literally pounded into him. By the time mother and son were reunited, Stone was essentially a street child, and by his early teens, a drunk and a drug user. A stint in the U.S. Navy introduced him to a “life more abundant,” although it also reinforced his appetite for intoxicants and women.

Not unreasonably, Bell maintains that Stone’s accomplishments more than outweigh his transgressions. And who would argue otherwise when his wife forgave him everything? While I wish there had been more about Stone’s early life, the daughter he fathered outside his marriage and the sexual partners who clearly influenced his fiction, Bell does a laudable job of explicating Stone’s novels, including the dark ones like “Outerbridge Reach,” and the breezy autobiography “Prime Green,” which describes Stone’s friendship with Ken Kesey. In the end, “Child of Light” leaves the reader with the urge to return to all of Robert Stone’s work — surely the best sign of a fine biography.

Michael Mewshaw‘s most recent book, “The Lost Prince: A Search for Pat Conroy,” was longlisted for the PEN biography award.

CHILD OF LIGHT

A Biography of Robert Stone

By Madison Smartt Bell

Doubleday.
608 pp. $35.