Clever derivatives broke dozens of companies. It killed them. Bankrupt. We don't need these kinds of innovation in finance. It's OK to be boring in finance. What we want is innovation in widgets.

You must know the big ideas in the big disciplines, and use them routinely - all of them, not just a few. Most people are trained in one model - economics, for example - and try to solve all problems in one way. You know the old saying: to the man with a hammer, the world looks like a nail. This is a dumb way of handling problems.

Economic systems work better when there's an extreme reliability ethos. And the traditional way to get a reliability ethos, at least in past generations in America, was through religion. The religions instilled guilt. ... And this guilt, derived from religion, has been a huge driver of a reliability ethos, which has been very helpful to economic outcomes for man.

Even bright people are going to have limited, really valuable insights in a very competitive world when they're fighting against other very bright, hardworking people. And it makes sense to load up on the very few good insights you have instead of pretending to know everything about everything at all times.

Accounting is a big subject and there are huge forces in play. The entire momentum of existing thinking and existing custom is in a direction that allows terrible follies to happen, and the terrible follies have terrible consequences.

It would be easier to screw up American Express than Coke or Gillette, but it's an immensely strong business.

Part of that, I think, is being able to tune out folly, as distinguished from recognizing wisdom. You've got whole categories of things you just bat away so your brain isn't cluttered with them. That way, you're better able to pick up a few sensible things to do.