Former Defense Secretary Donald Rumsfeld talks about his book "Known and Unknown." After leaving his position in the George W. Bush administration, he spent four years completing this book on his life. Mr. Rumsfeld has twice held the position of Secretary of Defense, in the George W. Bush administration and the Gerald Ford administration. Other offices include Chief of Staff to Gerald Ford, UN Representative to NATO, and a member of Congress. Mr. Rumsfeld talks about his philosophy of presidential staff leadership. He also compares and contrasts his years in government with those in business.