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.
Charlie MungerI did not succeed in life by intelligence. I succeeded because I have a long attention span.
Charlie MungerOver the long term, the eclipse rate of great civilizations being overtaken is 100%. So you know how it's going to end. (Laughter) I'm more optimistic about the staying power of what's good in this country. But just because you have a wonderful spouse doesn't mean you should treat her badly. You have the feeling that some of the old virtues [that made this country great] are lessening. But there's so much good and so much strength left that I would not expect this country to suddenly founder.
Charlie MungerAll intelligent investing is value investing - acquiring more that you are paying for. You must value the business in order to value the stock.
Charlie Munger