This book contains two of the most important and popular Sutras of the Buddhist world, summarizing all the richness and wisdom of the most fertile period of the Great Vehicle's evolution. They represent only a small part of the voluminous collection of texts of secret wisdom, the "Prajna Paramita" (that is, the "Perfect or Transcendent Wisdom"), which describes the perfect nature of things and the ways in which it is perceived and expressed by the human spirit. These texts are considered among the oldest and most fundamental of Mahayana.