Master yogi Iyengar offers what may turn out to be his last written words on the discipline that he helped popularize with Light on Yoga. Published in 1966, that first book became yoga's "bible" and set the standard for yoga books, providing pictures and instructions. The 86-year-old teacher here expounds the philosophy of yoga—its metaphysics, of which yoga poses, or asanas, represent the physical component. Iyengar yoga is vigorous because it involves the body, mind and spirit, and the master explains those interrelationships clearly. Chapters elaborate on aspects of yoga—the physical, energetic, mental, intellectual and divine, showing the architecture of the comprehensive system of spiritual teachings that lead to samadhi, the state of blissful absorption. Yoga is about health and purity, flexibility and divinity. While this book underlines the intellectual aspect of yoga, it is insufficient for a new yoga student, no substitute for yoga sadhana, practice that requires and integrates body and mind. Not the book with which to begin the yoga journey, it is highly recommended for those advanced on the path and interested in learning from a master of flexibility and wisdom.