The Present book is of the supreme significance from four points of view. Firstly, it breaks a new ground in Indian philosophy. According to it, the Self is not simply witnessing consciousness as maintained by Sankhya, Patanjala Yoga, Vedanta, but an active force of Spanda. Secondly, the ultimate reality is not simply a logical system, a mysterious background of bloodless categories, but spanda or living, throbbing Energy, the Divine creative Pulsation, the source of all manifestation, physical or superphysical. It should be of particular interest to science which has now come to the conclusion that matter is only an expression of electrical energy. Spanda maintains that all energy is, in its ultimate analysis, only an off-shoot of spiritual energy. Thirdly, the work elaborates the dynamic side of consciousness and serves as a commentary on the Siva Sutra. Fourthly, it gives hint of a new kind of yoga for the realization of self. Dr. Jaideva Singh has re-edited the text and the commentary with the assistance of his guru Swami Laksmana Joo. He has provided an English translation of both the text and Ksemaraja's commentary. He has thrown, in his notes, new light on many subtle points of the text and the commentary and given lucid exposition of each verse.