Book excerpt: One of the most influential living psychologists looks at the history of his life and discipline, and paints a much brighter future for everyone. When Martin E. P. Seligman first encountered psychology in the 1960s, the field was devoted to eliminating misery: it was the science of how past trauma creates present symptoms. Today, thanks in large part to Seligman's Positive Psychology movement, it is ever more focused not on what cripples life, but on what makes life worth living -- with profound consequences for our mental health. In this wise and eloquent memoir, spanning the most transformative years in the history of modern psychology, Seligman recounts how he learned to study optimism -- including a life-changing conversation with his five-year-old daughter. He tells the human stories behind some of his major findings, like CAVE, an analytical tool that predicts election outcomes (with shocking accuracy) based on the language used in campaign speeches, the international spread of Positive Education, the launch of the US Army's huge resilience program, and the canonical studies that birthed the theory of learned helplessness -- which he now reveals was incorrect. And he writes at length for the first time about his own battles with depression at a young age. In The Hope Circuit, Seligman makes a compelling and deeply personal case for the importance of virtues like hope, gratitude, and wisdom for our mental health. You will walk away from this book not just educated but deeply enriched.