The number one idea is to view a stock as an ownership of the business and to judge the staying quality of the business in terms of its competitive advantage. Look for more value in terms of discounted future cash-flow than you are paying for. Move only when you have an advantage.

Rationality is not just something you do so that you can make more money, it is a binding principle. Rationality is a really good idea. You must avoid the nonsense that is conventional in one's own time. It requires developing systems of thought that improve your batting average over time.

People calculate too much and think too little.

We have never had the will to enforce the immigration laws. What you see is what you'll continue to get.

Is there such thing as a cheerful pessimist? That's what I am.

Why should it be easy to do something that, if done well, two or three times, will make your family rich for life?

Although I am very interested in the subject of human misjudgment - and lord knows I've created a good bit of it - I don't think I've created my full statistical share, and I think that one of the reasons was I tried to do something about this terrible ignorance I left the Harvard Law School with.