Commonly known as the founder of Positive Psychology, Martin Seligman is a leading authority in the fields of Positive Psychology, resilience, learned helplessness, depression, optimism and pessimism. He is also a recognized authority on interventions that prevent depression, and build strengths and well-being. He has written more than 250 scholarly publications and 20 books. Dr. Seligman's books have been translated into more than twenty languages and have been best sellers both in America and abroad. Among his better-known works are Flourish, Authentic Happiness, Learned Optimism, The Optimistic Child, Helplessness, and Abnormal Psychology. His book Character Strengths and Virtues: A handbook and classification, was co-authored with Christopher Peterson. https://ppc.sas.upenn.edu/people/martin-ep-seligman