This book collects nearly two dozen classical writings on the use of sexual energy in achieving health and long life. It's a distinctly non-Western tradition, but presents a unified, interlocking set of ideas.
The largest part of this lore corresponds to Western alchemy. It uses many of the same metaphors, such as mercury, lead, and the crucible, and much of the same elliptical language. In a few places, the metaphors or code-words are so obscure that translators disagree wildly on their meanings, and even on whether the meanings can be reconstructed correctly. Other parts of the writings draw on mystical Taoism, Buddhism, and the same vital energies that explain acupuncture and traditional Chinese medicine. Not surprisingly, much of the tradition is aimed at male readers, with relatively little concern for the women. Despite the over-all male orientation, the last few selections do address women, with needs that sometimes match and sometimes differ from the men's. Even the men's writings address the importance of the woman's excitement, though, and describe the outwardly visible signs of its many stages.
However it is phrased or whoever it is addressed to, this set of practices is based on summoning and channeling sexual energy. Many of the authors use the "paired way" of coition to raise that power. Others use solo exercises in self-stimulation for the same purpose. This seems especially common in the women's texts, possibly because placing her needs before the man's would have been culturally unacceptable. The emphasis is on yogic self-discipline rather than exotic poses. Still, one author does offer a list of couplings with poetic names such Mandarin Ducks United (a pose I enjoy very much, because of range of additional caresses it makes possible). I recommend this book very highly to students of Asian thought and to anyone else who wants to see different perspectives on the practice and power of human sexuality.