This remarkable exploration of the inner principles of Gestalt therapy originated over 20 years ago in the form of a completed book, written at Fritz Perls' request. Now fully updated by the author, it is joined by a collection of essays that present the Naranjo's reassessment of Gestalt therapy for the present day. In his fascinating study Naranjo has captured the flavour and distinctive character of the California-based school of Gestalt therapy, propagated by Perls in his last years as a teacher and exemplar of the approach he pioneered. Lively and readible, learned and insightful, this book will be indispensible both for professionals and the lay-reader, demonstrating why Fritz Perls was truly the father of the now-flourishing human potential movement.