Inasmuch as this volume sets forth the very quintessence of the Great Path, the Mahayana, it not only supplements the three previous volumes, but is, in some respects, the most important member of the Series. At the time of the publication of Tibetan Yoga and Secret Doctrines, I did not, however, foresee that it was my destiny to be the transmitter of this additional volume.

In the General Introduction and the textual annotations there have been incorporated, to serve as a very necessary commentary, complementary teachings which were orally transmitted through a long line of Gurus of the Kargyütpa School to my own Tibetan Guru, the late Lama Kazi Dawa- Samdup. Also, in Book III, the teachings of the Guru Phadampa Sangay supplement those of the other Gurus.

Thanks to the kindly assistance of Lama Karma Sumdhon Paul and Lama Lobzang Mingyur Dorje, the first two successors of the late Lama Kazi Dawa-Samdup in the University of Calcutta, Book II, the essential part of this volume, has been rendered into English.

All who read this volume will join with me in offering homage to the late Sardar Bahadur S. W. Laden La, whom I had the great joy of assisting, in my capacity as scribe and editor, when he translated the excerpts from the Lotus- Born One's Biography, upon which the epitome of it, com- prising Book I, is based.