Not the usual category of book for which I write reviews. I am new to the study of eastern religions, and I enjoyed this book. About a third of it is devoted to a literal translation of a handbook on Vajrayan Buddhism which was published in the 1930s - pretty spicy stuff in those days, a veritable how-to list. But there is not much new in that part if you have read " The Joy of Sex" or any amount of other erotic literature. There are no pictures and if that is what you are interested in, you would do better by going to your local big-box bookstore. The strength of this book would seem to be in two areas. First, there is a detailed analysis by Jeffrey Hopkins, who evidently is a professor of Eastern Religions in London. Replete with footnotes. In a scholarly way, he re-interprets the imagery of the original author so that a modern reader would understand the references. Also, Hopkins has added a chapter 5 is titled "Sexual Pleasure and Spiritual Insight" and I thought it was the most illuminating section of the book. The chapter links the practice of yoga & meditation, the theory of spirituality, and the chakra system to the path of enlightenment, and also describes the nature of the link between sexuality in Tibetan Vajrayan ( also known as Tantric) practice with all these. The Chakra system is explained in detail; this has gained a lot of traction in "New Age" circles but I never really contemplate dwhat it was they were talking about, until now. Chakras are a theme of Hindusim and Buddhism. I confess that maybe I should have known all this, and maybe there will be those who take it for granted....but it did not come together in a cohesive whole before this.