In America, yoga has so often devolved into a physical practice with spiritual pretensions, instead of a deeply spiritual practice.
I returned from India from a six-month trip in 1998, during which time I stumbled into meeting a guru and then spent five weeks studying with him in Benares. When I came home, it was very hard to begin to articulate what had taken place. This book was a godsend, a link to connect my experience with a tradition that extends millennia back in time. And secondly it helped to link my friends and family to the experiences I just had by reading a clear description of the path and experiences involved in Tantra.
I hesitate even to use the word Tantra, given that it's so very, very misused in the West.
This book sets the record straight (Tantra does NOT equal sex) and presents the practice and history of Tantra in all its profundity. We are indebted to the author for his great gift to all of us.
For the other reviews that criticize the author's lack of experience in Tantra, you should be aware that the author has a Tantric Buddhist teacher which led him to bring his considerable talents to present the first guide and most helpful explanation of these profoundly important teachings.
I've given numerous copies to family and friends, all of whom have enjoyed it immensely.
Until Karen Armstrong decides to tackle this subject (highly unlikely, given her orientation), this is the best book available. Highest recommendation!