What Warren Buffett Understood About Capitalism

A few days ago, Warren Buffett, the most successful investor in history, said he would retire as C.E.O. of Berkshire Hathaway, the conglomerate that he built into a trillion-dollar colossus. Andrew Ross Sorkin, who has covered Mr. Buffett for many years, discusses the career of the man who both personified and critiqued American capitalism.