We regard using [a stock's] volatility as a measure of risk is nuts. Risk to us is 1) the risk of permanent loss of capital, or 2) the risk of inadequate return. Some great businesses have very volatile returns - for example, See's [a candy company owned by Berkshire] usually loses money in two quarters of each year - and some terrible businesses can have steady results.

Proper accounting is like engineering. You need a margin of safety. Thank God we don't design bridges and airplanes the way we do accounting.

I think I've been in the top 5% of my age cohort all my life in understanding the power of incentives, and all my life I've underestimated it.

It would be one of the most irritating experiences in the world to do a lot of work to uncover a fraud and then at have it go from X to 3X and at h the crooks happily partying with your money while you're meeting margin calls. Why would you want to go within hailing distance of that?

The old culture had come out of poverty, out of English customs.

The ethical rule is from Samuel Johnson who believed that maintenance of easily removable ignorance by a responsible office holder was treacherous malfeasance in meeting moral obligation. The prudential rule is that underlying the old Warner & Swasey advertisement for machine tools: "The man who needs a new machine tool, and hasn't bought it, is already paying for it". The Warner & Swasey rule also applies, I believe, to thinking tools. If you don't have the right thinking tools, you, and the people you seek to help, are already suffering from your easily removable ignorance.

If only I had the influence with my wife and children that I have in some other quarters!