The Para¯tris¿ika¯ Vivaran¿a by the great Kashmiri philosopher and mystic Abhinavagupta is an extensive commentary on the Para¯tris¿ika¯ Tantra, and it is one of the most profound texts, not only of non-dualist Kashmir S¿aivism, but of Indian philosophy and mysticism in general. The present work attempts to make this difficult text accessible, by culling out the important themes and offering an interpretation. The main focus is on the understanding of the Absolute (Anuttara) and the ways to realize it. The central theme of mantra also leads to a mysticism of language with its philosophical implications. All these reflections and practices are inscribed in the theory that "everything is related to the totality", "every part contains the whole of reality" (sarvam sarva¯tmakam). It is this holistic vision of Abhinavagupta, based on the Tantras, which makes this work so relevant in our times of fragmented aspects of life and knowledge in search of integration. No doubt, in the view of the Tantra and of Abhinavagupta, language and mantra provide the key.