Siva Advaita is the philosophy of Shrikantha as expounded in his Brahma Sutra Bhashya, a Saivite commentary on the Brahma Sutras (ca 500-200 bce). The Brahma Sutras are 550 terse verses by Badarayana summarizing the Upanishads. The Brahma Sutras, the Bhagavad Gita and the Upanishads are the three central scriptures of the various interpretations of Vedanta philosophy. Shankara, Ramanuja and Madhva wrote commentaries on these books deriving three quite different philosophies-nondualism, qualified nondualism and dualism, respectively-from the same texts. Each claimed his to be the true interpretation of the Vedas and vigorously refuted all other interpretations. Shankara was a monist and accorded worship of the personal God a lesser status. Ramanuja and Madhva, on the other hand, developed theistic philosophies in which devotion to Vishnu was the highest path. There was as yet no school of Vedanta elevating devotion to Siva to similar heights.