This book is the first coherent dictionary in English to explain the basic concepts of all the major schools of Raja Yoga and Hatha Yoga. The author, formerly Professor of Physics at the Sindh National College of India and lecturer at the University of Madras, is one of the eminent scholars of ancient philosophy and psychology of India. For many years he was also a teacher of Sanskrit and worked closely with many Indian scientists and yogis. He was accepted into the Vedantist Order of the Sringeri Monastery and ordained in the name of the great teacher Sri Shankaracharya of Sringeri.