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

Just keep your head down and do your best.

A lot of opportunities in life tend to last a short while, due to some temporary inefficiency... For each of us, really good investment opportunities aren't going to come along too often and won't last too long, so you've got to be ready to act and have a prepared mind.

When you locate a bargain, you must ask, 'Why me, God? Why am I the only one who could find this bargain?'

We believe there should be a huge area between everything you should do and everything you can do without getting into legal trouble. I don't think you should come anywhere near that line. We don't deserve much credit for this. It helps us make more money. I'd like to believe that we'd behave well even if it didn't work. But more often, we've made extra money from doing the right thing. Ben Franklin said I'm not moral because of it's the right thing to do - but because it's the best policy.

So, economics should emulate physics' basic ethos, but its search for precision in physics-like formulas is almost always wrong in economics.

[In picking stocks] You really have to know a lot about business. You have to know a lot about competitive advantage. You have to know a lot about the maintainability of competitive advantage. You have to have a mind that quantifies things in terms of value. And you have to be able to compare those values with other values available in the stock market.