and was born about the year 788. Taking his stand upon the Upanishads, Brahma-sūtra, and Bhagavad-gītā, upon which he wrote commentaries, he interpreted them as teaching the doctrine of Advaita, thorough monistic idealism, teaching that the universal Soul, Brahma, is absolutely identical with the individual Soul, the ātmā or Self, that all being is only one, that salvation consists in the identification of these two, and is attained by knowledge, the intuition of their identity, and that the phenomenal universe or manifold of experience is simply an illusion (māyā) conjured up in Brahma by his congenital nature, but really alien to him — in fact, a kind of disease in Brahma. This was not new: it had been taught by some ancient schools of Aupanishadas, and was very like the doctrine of some of the Buddhist idealists; but the vigour and skill with which Śaṃkara propagated his doctrines threatened ruin to orthodox Vaishṇava theologians, and roused them to counter-campaigns. Among the Vaishṇava Brahmans of the South who won laurels in this field was Yāmunāchārya, who lived about 1050, and was the grandson of Nātha Muni, who collected the hymns of the Āl̤vārs in the Nāl-āyira-prabandham and founded the great school of Vaishṇava theology at Srirangam. In opposition to Śaṃkara's monism, Yāmunāchārya propounded the doctrine of his school, the so-called Viśishṭādvaita, which
