The world is simultaneously facing many crises that humanity is failing to solve. Yet, at the same time, humans are smarter (with IQs on average thirty points higher than a century ago) and more knowledgeable (with the world's knowledge base at our fingertips), and scientific advances are accelerating. However, intelligence and knowledge are not enough: wisdom harnesses these strengths to serve the common good. Education is focused on acquiring knowledge, but schools would do better also to teach and test for the development of wisdom. To a lot of people, wisdom is an abstraction, but there is a growing body of scientific research into what wisdom is and how it works. This introduction sets out why wisdom is so important. Drawing on insights from psychology, philosophy, science, and common sense, this book provides a complete account of wisdom and how we can develop it throughout our lives.