Renowned senior member of the adult development, leadership, and organization transformation fields, award-winning researcher, consultant, and teacher, Bill Torbert offers us this final and signature book -- an anti-heroic memoir named Numbskull that shares his dramatic early life in Spain, Austria, Italy, and Somalia, then at Yale, the Southern Methodist University Business School, and the Harvard Ed School, culminating with the creation of The Theatre of Inquiry. He recounts for us how he gradually learned, from the experiences of his own leadership efforts, a theory of learning from experience. From his experiences, he also learned a theory of organizational transformation, culminating in 'liberating disciplines' that help others learn transformationally from their own experiences. And, last but not least, he formulated a developmental theory of social science that culminates in the paradigm of Collaborative Developmental Action Inquiry (CDAI). CDAI interweaves first-, second-, and third-person research and practice, as Numbskull illustrates by surrounding Bill's first-person memoir with an introduction, a postscript, and endnotes in the second-person voices of his action inquiry colleagues, as well as appendixes in the third-person voice. Torbert received his BA and PhD from Yale, played leadership roles at Yale Upward Bound and The Theatre of Inquiry, later served as Graduate Dean at Boston College (where the MBA rose from below the top 100 to the top 25 during his tenure) and as Director of the PhD program in Organizational Transformation. He consulted and served as a board member at dozens of companies, and is the author of a dozen books including the award-winning Managing the Corporate Dream, award-finalist The Power of Balance: Transforming Self, Society, and Scientific Inquiry, and Action Inquiry: The Secret of Timely and Transforming Leadership, translated into Chinese, Russian, and Japanese. Of his nearly 100 journal articles and book chapters, the best-known is his 2005 international-award-winning, Harvard Business Review article "Seven Transformations of Leadership" (co-authored with David Rooke). Partnering first with Susann Cook-Greuter and later with Elaine Herdman-Barker, he has transformed the Washington University Sentence Completion Test into the leadership development psychometric named the Global Leadership Profile. He currently serves as a founding board member of both Global Leadership Associates and Amara Collaboration and is