Vedanta means the “end of the Veda” and refers to the Upanishads, those teachings which investigate the nature of the soul and ultimate reality and which are the last part of the Vedic corpus. The term also designates the philosophical system of classical Hindu thought that has been primarily based on the exegesis of the Upanishads (along with the Brahma Sutras and the Bhagavad Gita). Most adherents of Vedanta share the following assumptions: Brahman is the underlying Reality pervading the universe; the transmigration of the soul; and the possibility of moksha or liberation from this cycle of transmigration, through deep insight. Vedantists do not, however, agree upon the relationship between Brahman and Atman (the soul). Some, following Shankara (c. 9th century C.E.), insist upon the ultimate nonduality of the two; others agree with qualified nondualism of Ramanuja (11th century) or with the radical dualism of Madhva (13th century).