His wife had tried to dissuade him. He was 79 years old, and lately his health had been shaky, complications involving his heart transplant of a dozen years ago. Why subject himself to the stress? At the airport the day before, while waiting for the 7:30 a.m. flight from Philadelphia to the West Coast, even he had exclaimed, "This is madness!"

But John Clifton Bogle - "Please, just call me Jack" - doesn't trifle with commitments. The founder and former chairman of Vanguard Group Inc., the mutual-fund giant headquartered in Malvern, had attended every reunion of the Boglehead Diehards, disciples brought together by the Internet, since their first gathering in Miami in 2000, and he wasn't about to miss this one, even if it meant traveling to San Diego.

Truth be told, it was immensely flattering, and nourishing to his ego (a not inconsiderable component of Bogle's personality), that a group of small "man-on-the-street" investors so admired him and his philosophy of growing money.

The Boglehead Diehards sponsor an increasingly popular Web forum where they answer questions, trade investment advice, and offer encouragement (www.bogleheads.org). Most entrust their money to Vanguard and religiously follow Bogle's principles: keep it simple; invest, don't speculate; put your money in low-cost index funds tied to the performance of the entire stock market; and keep it there forever, or at least a very long time.

At the reunion last month, the Bogleheads treated him like a wise and beloved grandfather. The current of events had heightened his appeal, making him seem prophetic. The week before, Wall Street had collapsed, and as Congress mulled a bailout, the 130 Bogleheads were eager to receive counsel from this éminence grise of the financial world.

"The handwriting was on the wall for all this to happen a long time ago," Bogle told them. "The financial sector, with all its sins, would in times less generous be hoist by its own petard - to wit, blown up by its own dynamite. And, of course, that is what happened."

Bogle looked natty in a Vanguard blazer over an orange-and-white striped polo shirt. His face was as craggy as the coast of Maine. His frame was lean, his shoulders were stooped, and he cinched his trousers north of his navel. He was courteous, congenial, chipper ("I love the morning! I can't wait to take on the day!"), displaying all the appealing traits of what used to be called "good breeding."

His crisp bass voice resonated with the confidence of his class, the extinct majesty of moral authority.

"Investment bankers caused this mess, and apparently they're not going to pay anything to get out of it!"

"Any time you have a system that privatizes the rewards of an enterprise and socializes the risks, you're going to be in trouble!"

"The stock market is a giant distraction from the business of investing. Investing is earning a return on your capital; speculation is betting on price. It's so insane to have a market where it's almost all rank speculation and no investment!"

"In Las Vegas, do the gamblers win? No. The croupiers win! That's the way the Wall Street system works. That's why we've got this overloading of wealth, the top one-tenth of 1 percent making obscene amounts of money for subtracting value from society. I don't like it!"

This bear market, his 10th, is unlike any other, he said; the contagion has spread from the financial sector to the "real economy," so expect a "tough slog" ahead. His advice: Stay the course; do nothing rash; this, too, shall pass. He also offered a preview of his book Enough: True Measures of Money, Business, and Life.

They stood in line for autographs. They posed for pictures with him. They thanked him for giving the small investor "a fair shake," for enabling them to retire early, to buy or build their dream houses, to finance their children's college education, to live in comfort and security.

"We're an affirmation of his life's work," said Michael LeBoeuf, 66, of Paradise Valley, Ariz., a coauthor of The Bogleheads' Guide to Investing, who was wearing a "Jack Bogle for President" button. "Some mutual-fund managers chose to make millions. Jack Bogle chose to make a difference."

"He has financially changed my life," said Jesse Payne, 66, a real estate investor and retired New York City police officer.

"There's God," he said, placing his hand over his head to indicate the Almighty's lofty position, before dropping it slightly, "and there's Bogle."

A new kind of firm

These days especially, Bogle is much in demand, a rock star of the financial world, and he is regularly recognized - and quizzed - at airports, on trains and in taxicabs.

But in Philadelphia, where he has lived since 1945, and where he built one of the region's largest, most successful businesses (Vanguard has 12,000 employees and oversees nearly $1.2 trillion in assets), and where he helped foster the National Constitution Center, serving as its chairman for nearly eight years, Bogle is less known than, say, Bill Giles of the Phillies or Brian Roberts of Comcast.