Martin E. P. Seligman is the most influential psychologist in the world (Academic Influence) and a professor at the University of Pennsylvania, where he directs the Positive Psychology Center. A former president of the American Psychological Association, he earned his BA in philosophy from Princeton and his PhD in psychology from Penn, and holds ten honorary doctorates. His research—from learned helplessness to learned optimism to prospection—has reshaped how science understands human well-being. He is the author of more than thirty books, including Flourish, Authentic Happiness, The Hope Circuit, and Tomorrowmind.