M. Scott Peck, 69, a psychiatrist who wrote the landmark self-help book "The Road Less Traveled" but said he often had a hard time following his advice of self-discipline, died Sept. 25 at his home on Bliss Road in Warren, Conn. He had Parkinson's disease as well as pancreatic and liver duct cancer.

Dr. Peck was enjoying a brisk private practice in Connecticut when he wrote "The Road Less Traveled" (1978). It reportedly sold more than 10 million copies, was translated into 20 languages, spent eight years on the New York Times bestseller list and launched a franchise of books, including "Further Along the Road Less Traveled" (1993) and "The Road Less Traveled and Beyond" (1997).

With a compassionate narrative style, Dr. Peck's books emphasized personal responsibility and self-discipline. "Life is difficult," he wrote in the opening line of "The Road Less Traveled," moving on to address themes he labeled discipline, love, growth and religion, and grace.

Though he said one publisher dismissed it as "too Christ-y," "The Road Less Traveled" was credited with boosting the publishing industry's interest in self-help texts, especially those with a spiritual flavoring. Dr. Peck was sometimes regarded as the modern father of the genre, but he had trouble with those who called him a prophet, which many of his followers did.

Dr. Peck became one of the best-known psychiatrists, speakers and spiritual teachers of his generation, even if some in his field came to frown on his meshing of mental health and spirituality.

Raised in a secular home, his own religious track ranged from Zen Buddhist (at 18) to a flirtation with Jewish and Muslim mysticism (in his thirties) and Christianity (at 43).

With his first book, he became rich and famous. He held workshops and lectures on such subjects as "Self-Love Versus Self-Esteem" and "Sexuality & Spirituality: Kissing Cousins."

He said he was repulsed and pleased by some of the cult aspects that formed around him. "Half the time when people want to touch my robe," he once told Life magazine, "it feels incredibly icky -- yuck!" The rest of the time, "it feels very good, honest, right."

He described himself as a flawed man who had a weakness for cheap gin, marijuana and women. He wrote openly of his extramarital affairs in what he called his favorite book, "In Search of Stones" (1995), nominally about a trip to Great Britain looking for ancient stone monuments.

"There was an element of quest in my extra-marital romances," he wrote. "I was questing, through sexual romance, at least a brief visit to God's castle." He later said his philandering stopped when he became impotent.

Morgan Scott Peck was born in New York on May 22, 1936. He said his father, a lawyer and judge, hid his Jewishness by passing as a Wasp.

Much of his childhood was spent in a jealous rage toward his late older brother. His brother was "very adventurous. Even in his sixties, he was riding his bike on ice," he said, whereas he had always seen himself as "a physical chicken."

He attended Phillips Exeter Academy, which he later derided for its "Spartan, almost vicious adolescent culture." After some psychological counseling, he switched to the Friends Seminary, a Quaker school near Greenwich Village where he discovered Zen Buddhism.

That was followed by a brief stint at Middlebury College, where he protested attending the required ROTC classes. He said his father's connections got him into Harvard University.

After his Harvard graduation in 1958, he married a woman of Chinese descent, and his father disinherited him briefly. He graduated from Case Western Reserve University medical school in 1963 and joined the Army because it was the cheapest way to continue studying medicine, he said.

He spent nine years as an Army psychiatrist, becoming a vocal opponent of the Vietnam War. After the atrocities at My Lai, he wrote to superiors unsuccessfully requesting a study of earlier military massacres.

He resigned in 1972 to start a private practice in Litchfield County, Conn., in the leafy northwest part of the state.

Dr. Peck received a $7,500 advance from Simon & Schuster for "The Road Less Traveled" and said he had a feeling it would be a great success. The biggest boost came from author Phyllis Theroux's rave in The Washington Post ("a clipper ship among Chris Crafts, a magnificent boat of a book.")

It became a phenomenon and reportedly netted Dr. Peck $300,000 in annual royalties. He was skeptical, however, of how many people had actually read the words.

So was Time magazine, which in 1994 wrote that the book's lingering appeal "may not be that people actually read it and are elevated. Rather, it appears, they buy it to give to irritating friends. Making a present of 'The Road Less Traveled' has become a socially acceptable way of saying, 'Estelle, your insulation is beginning to char.' "

Dr. Peck also wrote "People of the Lie: The Hope for Healing Human Evil" (1983), a case study of human pretenses; two novels; and a children's book, "The Friendly Snowflake" (1992). He had a long fascination with exorcisms that he explored in "Glimpses of the Devil" (2005).

His marriage to the former Lily Ho ended in divorce.

Survivors include his second wife, Kathleen Kline Yates Peck, whom he married in 2004; three children from the first marriage; and two grandchildren.

Speaking of his conversion to Christianity, he said he had an appreciation of Jesus Christ as someone "who was almost continually frustrated." He told Omni magazine, "He was a man who was often angry, scared, sad or even prejudiced on occasion." He had little regard for what he told another interviewer was the ever-smiling "wimpy Jesus." He once hung up the phone on a bothersome caller, justifying the action by saying that Jesus would have done the same.

Psychiatrist M. Scott Peck helped start a boom in self-help books.