True independence – meaning the willingness to challenge a forceful CEO when something is wrong or foolish – is an enormously valuable trait in a director. It is also rare. The place to look for it is among high-grade people whose interests are in line with those of rank-and-file shareholders – and in line in a very big way.
Warren Buffett – American value investor, Chairman of Berkshire Hathaway (b. 1930), Quotations book 2016