The possibility that stock value in aggregate can become irrationally high is contrary to the hard-form "efficient market" theory that many of you once learned as gospel from your mistaken professors of yore. Your mistaken professors were too much influenced by "rational man" models of human behavior from economics and too little by "foolish man" models from psychology and real-world experience.

We don't claim to have perfect morals, but at least we have a huge area of things that, while legal, are beneath us. We won't do them. Currently, there's a culture in Americathat says that anything that won't send you to prison is OK.

Those of us who have been very fortunate have a duty to give back. Whether one gives a lot as one goes along as I do or a little and then a lot [when one dies] as Warrendoes is a matter of personal preference. I would hate to have people ask me for money all day long.

Part of [having uncommon sense] is being able to tune out folly, as opposed to recognizing wisdom. If you bat away many things, you don't clutter yourself.

Suppose you were a real estate investor with a 1/3 interest in the best apartment complex in town, the best mall, and the best office building. Would you feel like a poor, undiversified investor? No! But as soon as you get into stocks, people feel this way. Partly, people need to justify their fees.

I don't want to sell credit to people who are going to hurt themselves with it. You should only sell products that are good for the people who use them. Some disagree with this, but I know I'm right. That is to say, you're talking to a Republican who admires Elizabeth Warren.

Economics is in many respects the queen of the soft sciences. It's expected to be better than the rest. It's my view that economics is better at the multi-disciplinary stuff than the rest of the soft science. And it's also my view that it's still lousy.