During times of stock market volatility, it's always interesting to turn to rational, market-tested individuals who have seen it all already. With that in mind, Business Week recently sat down with 80-year-old Jack Bogle, the founder and former CEO of Vanguard Group, to get his take on the market. Bogle, respected and well-known as the father of index investing and straight-ahead, common sense investing, is actually surprisingly optimistic about future stock market returns:

"If you're in your 20s to 40s, keep going. These are good values. The stock market has taken an awful lot of this mess into account, and it's hard for me to believe that common equities won't do better than Treasuries from this point on." Bogle thinks that a 7% nominal return—more than twice Treasury bonds—is realizable over the next decade."

But what about the next 12-18 months? According to Bogle, the stock market will be a leading - not lagging - indicator of economic recovery: "This downturn could last 1½ years to 2 years. But the stock market will recover months before a turnaround comes. Don't try to time your entry."

And don't miss this other recent Business Week feature on Bogle, either, where he discusses the future of the retirement savings system. At an age when others would be content to rest on their laurels, Bogle is still out campaigning for the little guy. A big hat tip to Mr. Bogle!