The Paratrisika (or Paratrimsika) is a short Tantra which has been held in the highest esteem by Kashmir Saivism or Trika. After Somananda, Abhinavagupta has written two commentaries on it, a short one (Laghuvrtti) and an extensive one the present Vivarana which is presented here for the first time in an English translation. The Paratrisika Vivarana is one of the most fascinating but also most difficult texts of the Kashmir Saiva School, and of the mystical philosophical literature of India as a whole. It deals with Ultimate Reality (anuttara or para) and with the methods of realization, centred above all in the theory and practice of the mantra. Abhinavagupta displays here his great exegetical genius and presents a penetrating metaphysics of language, of the Word (vak) and its various stages in relation to consciousness. His language reflects in a luminous fashion the mystical experience contained in this text. The present translation of Abhinavagupta's masterpiece will not only be a milestone in the study of Kashmir Saivism, but it also makes available one of the major mystical texts of the Indian tradition to readers interested in philosophy and spirituality.