From the beginning of his career as a poet, William Butler Yeats made serious efforts to learn and master the complex and abstruse Indian religious-philosophical- artistic system and tried to learn Indian philosophy system which he could use in his poems and other works. But what he borrowed from his Indian sources depended upon what he liked at a particular phase of his career, and upon his own ideas of art during that phase. Whether he liked the ascetic aspects or the life-affirming aspects of Indian philosophy was decided by his temperament as well as his changing ideas of art. For example, in the early part of his life when he was so feeble and weak as to escape into unrealistic world, his interest in asceticism, contemplation and the search for truth was strengthened through his own reading and associating with Chatterji. In his middle phase of life, after meeting Tagore and reading his Gitanjali, he learned the Upanishadic idea of the self. In his later part of life when he affirmed and accepted life and this world as a natural condition, he met Shri Purohit Swami. Under the influence of Swami his ideas of art once again favored celebrating the supernatural, but simultaneously they were glorifying human passions. Sexuality and passion appeared to him aspects that could be sung about with intimacy. Instinct began to appear to him very sacred. He was turning to another phase of Indian philosophy which attributes sacredness to spontaneity. Yeats began to integrate the natural and the supernatural through his art so that his art becomes a new religion with spiritual overtones and with the warmth of the passions of life.