MANY books have already been written on Indian religious philosophy. Their exhaustive study of Indian teachings as contained in the Vedas, Upanishads, Yoga Pradipika, and in the teachings of Patanjali, Sankaracharya, etc., make it unnecessary to discuss the theoretical side of Yoga and Yoga philosophy. It seems to us much more appropriate to give a practical introduction to Yoga as it actually is. In the Occident, a large section of opinion still gives credence to the erroneous notion that Yoga is a kind of religious revelation applicable only to Eastern peoples; too often it is assumed that Yoga conflicts with Christian teachings and is of no use to those living in the West. It is our aim to correct this error, because for many seekers after God such a misunderstanding blocks the shortest path toward the Kingdom of Heaven.