This is the first English translation of one of the most-revered texts in Tibetan Buddhism. As part of the rDzog-chen or Ati tradition, Primordial Experience was written by Manjusrimitra, an Indian disciple of the first teacher of Ati yoga. Legend has it that the teacher, in a debate about the Buddhist doctrine of cause and effect, opened his student's eyes to the reality of Ati yoga, the state of pure and total presence. This book is the result of that encounter. Included is a preface by Namkhai Norbu that places this text in the Ati tradition, as well as a substantial introduction about the theory of translation, the history of the text and its author, philosophical questions about the relation of Ati yoga to "Buddhist Idealism, " and the meditation practice linked with this text.