This book has little to do with yoga or the Yoga Sutras and states this in the introduction. The author did not read the sutras, but had them translated by an unidentified "Tibetan" which she then summarizes. The result is a mixture of Protestant Christianity, Hinduism, Theosophy, with a hint of yoga and a large dollop of colonialism chopped together into a very weird spiritual salsa. As an example of the Theosophy being practiced during the time of Blavatsky, it's fairly classic which is probably the only redeeming factor.