John C. Bogle is the founder and retired CEO of The Vanguard Group, the largest mutual-fund organization in the world, with more than 160 mutual funds and current assets totaling more than $1.4 trillion. Since his retirement from Vanguard in 1996, Bogle has spent his time studying, writing, and speaking on the financial markets and mutual funds. He is president of the Bogle Financial Markets Research Center, created in 2000 to support his ongoing work on behalf of investors.

Bogle is optimistic about Vanguard's future, given its mission to serve. Other companies have demutualized, which he sees as a risk for Vanguard, but an unlikely one. Ultimately -- barring a major crisis that affects the entire market -- he doesn't see any barriers to the firm's future success.

Tom Gardner: You're optimistic about what Vanguard will become over the next 100 years.

Jack Bogle: Where you are, you have to be optimistic.

There are risks out there. Will they ever try and "de-mutualize" the company? That's happened in a lot of places. I don't think it can happen there, but anything can happen in this world when you've got human beings involved.

I think it's important, even as we maintain the letter, or the implementation of a mutual structure, we have to maintain the spirit of that mutual structure too, and that requires some doing.

You've got to keep your mind on the mission -- that your mission is to serve, day after day after day.

It's very difficult to see anything that can get in the way of that, except some massive thing like a huge stock market collapse; that would not be good for us. Every once in a while, we (unclear) some of these new funds. I have a little question mark about, "You must be betting they're better than an index fund." I wouldn't even look. I'd just say, "I bet they're not," because nothing can be in the long run.

I watch. I think people at Vanguard really -- I don't want to overdo this -- but I think they love me. I'm a normal human being -- more or less normal anyway! I'm straightforward; they can identify with that. Even the people that have been there for a very short period of time seem to know who I am.

Gardner: It's total authenticity, which means sometimes we'll agree, sometimes we won't agree.

Bogle: Yes.

Gardner: A member of ours named Vicki was bringing up the importance of skin in the game. You've had skin in the game with the business, and have your capital with the Vanguard funds to this day.

The mix of those qualities -- even though it may lead to some public disagreement -- is overall a benefit to both the organization, to you, and to the outcome for the customers of that.

Bogle: I really don't care who benefits or who doesn't benefit. I have to tell it as I see it. I've been able to do that for a long, long time.

I was key to Vanguard going into business. You walk a road that you think is the right road. You walk it as straight as you can. You be as honest as you can.

I've gotten so I find confessing my mistakes, of which the number in my career -- I don't even want to get into hundreds, thousands, I don't know how many I've made -- an infinite number, maybe, in my career; it's kind of liberating to say, "I really blew that one."

I blew a lot of stuff. But the underlying thesis, if you will -- the underlying concept, the underlying idea of owning a market, whatever the market may be, and getting your fair share -- has worked and will work. Who else can say that about what's going on in their own company?

Gardner: Small failures all the way to great success.