Michael Mann is one of the most influential sociologists writing today. His three-volume work The Sources of Social Power, the third volume of which has just been completed, has transformed our way of thinking about power and has rewritten the history of human societies. No one interested in understanding how the modern world was shaped, how we got to where we are today, and where we're likely to be heading can afford to ignore this modern classic. Michael Mann is, as John Hall aptly describes him, a Max Weber for our times. In this new book Michael Mann reflects on the meaning of his project as a whole, both as a contribution to social theory and as a guide to the options and constraints that face the contemporary world now and in the near future. He gives sustained attention to the situation of the United States, the nature of the challenge that may come from China, the unrestrained and perhaps unrestrainable power of finance, and the looming crisis of environmental degradation. This concise and accessible book is the ideal introduction to the work and thought of one of the most original social scientists in the world today. Students and scholars will find the book invaluable, and general readers will find in this book a clear and masterful guide to the key challenges we face in the years and decades ahead.