I put heavy weight on certainty. It's not risky to buy securities at a fraction of what they're worth.

That's the reality of what they're going to sell them to the Treasury for.

If you understood a business perfectly and the future of the business, you need very little in the way of a margin of safety.

Cash, though, is to a business as oxygen is to an individual: never thought about when it is present, the only thing in mind when it is absent... When bills come due, only cash is legal tender. Don't leave home without it.

Our approach is very much profiting from lack of change rather than from change. With Wrigley chewing gum, it's the lack of change that appeals to me. I don't think it is going to be hurt by the Internet. That's the kind of business I like.

Does the business have a consistent operating history?

If you don't feel comfortable owning something for 10 years, then don't own it for 10 minutes.