This 1927 classic is a systematic introduction to Hindu mysticism as it evolved in India through the ages. This book gives a brief general outline of some of the most important types of mysticism, indicating their mutual relations, sometimes genetically and sometimes logically. These include early sacrificial, Upanisadic, Yogic, Buddhistic, and Classical as well as Popular Bhakti cult explaining concisely and clearly their main characteristics, basing the interpretations directly on the original sources.