Russell “Russ” Ackoff was one of the great minds of the 20th century. He was a longtime resident of Philadelphia, Pennsylvania, and is widely recognized as one of the world’s leading authorities on Systems Thinking. For more than 20 years he was a professor of Systems Science at the Wharton School of business, and he was a lifelong friend of both Peter Drucker and W. E. Deming. His leadership theory defined a nascent branch of industrial engineering. He went on to write 30 other books, becoming one of the most influential management thinkers of our time.