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.

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.

The harder you work, the more confidence you get. But you may be working hard on something that is false.

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 you have only a little capital and are young today, there are fewer opportunities than when I was young. Back then, we had just come out of a depression. Capitalism was a bad word. There had been abuses in the 1920s. A joke going around then was the guy who said, 'I bought stock for my old age and it worked - in six months, I feel like an old man!' "It's tougher for you, but that doesn't mean you won't do well - it just may take more time. But what the heck, you may live longer."

In engineering, people have a big margin of safety. But in the financial world, people don't give a damn about safety. They let it balloon and balloon and balloon. It's aided by false accounting.

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.