An outline of the secret Hindu teachings. This work consists of a series of twelve impromptu lectures. Contents: an outline of yoga philosophy; asana, bodily posture; pranayama, breathing exercises; mantrayoga, chants, and pratyahara, meditation; dharana, concentration; dhyana, unification, and samadhi, cosmic consciousness; kundalini, secret energy, and how it is aroused; guardians of the threshold; relation of yoga to occultism and to psychics; projection of the astral body.