He advocates taxes to discourage short-term speculation. He wants limits on leverage, transparency for financial derivatives, stricter punishments for financial crimes and, perhaps most urgently, a unified fiduciary standard for all money managers: “A fiduciary standard means, basically, put the interests of the client first. No excuses. Period.”

Those clients — the ordinary people to whom he has always appealed — need to protect themselves from peril, he says: “In an ideal world, Adam Smith-like, individuals would recognize what they need to do in their own self-interest, and they will make changes happen and look after themselves.”

MR. BOGLE sometimes disagrees with current Vanguard management, but he remains proud of the company he created. Index funds are ever more popular, and Vanguard is gushing money, torrents of it. Thanks largely to its various index funds, Vanguard, which is based near Valley Forge, Pa., pulled in a net $87.7 billion in cash this year through June, excluding money market funds. That’s nearly 40 percent of the cash flow of the entire mutual fund industry.

Burton Malkiel, the Princeton economist and author of “A Random Walk Down Wall Street,” says: “Index funds are so popular now that it’s easy to forget how courageous and tenacious Jack Bogle was in starting them. They were called Bogle’s Folly because all they did was replicate the returns of the market. But, of course, that’s a great deal. In the academic world many people saw the wisdom of this — but Jack is the guy who actually made it happen.”

Mr. Bogle also tried to ensure that Vanguard funds would always be cheap to buy and hold. While Vanguard is his baby, he has never had an ownership stake in it aside from the shares he holds in its mutual funds. Vanguard fund shareholders own the place collectively because he planned it that way.

“Strategy follows structure,” he says, explaining that with no parent company or private owners to siphon profits, Vanguard can keep costs lower than anyone else. That was always his goal. “The only way anyone can really compete with us on costs is to adopt a mutual ownership structure,” he says. “I’ve been waiting all these years for someone to do it, but no one has.”