This book is a systematic introduction to Hindu mysticism as it evolved in India through the ages. Mysticism is not an intellectual theory, It is fundamentally an active, formative, creative, elevating and ennobling principle of life. According to the author, mysticism means a spiritual grasp of the aims and problems of life in a much more real and ultimate manner than is possible to mere reason. This small book gives a brief general outline of some of the most important types of mysticism, indicating theirmutual relations, sometimes genetically and and sometimes logically. After describing the sacrificial type of mysticism, it discusses the four chief types of mysticism - the Upanishadic, the Yogic, the Buddhistic and the Bhakti. Their striking characteristics have been briefly touched upon and materials have largely been drawn directly from the original sources.