William CohenWILLIAM A. COHEN, PH.D., President of the Institute of Leader Arts and The California Institute of Advanced Management, was Drucker's first executive Ph.D. graduate. About him, Drucker wrote: "My colleagues on the faculty and I learned at least as muh as we could teach him." He has held executive positions in several companies and served as president of two universities. He is the author of many books, including Heroic Leadership, A Class with Drucker, Drucker on Leadership, and Drucker on Marketing. Read More Read Less