Sankaracharya's advent was at a time when there was spiritual and moral chaos; the ancient Vedic injunctions were being misinterpreted, the simple and noble teachings of Buddha twisted and abused. He took upon the task of integrating Indian thought by redefining the ancient concepts and reinterpreting in the right way, Brahma sutra, Upanishads and the Geeta. He is the exponent of Advaita Vedanta which is the most scientific and logical type of philosophy. The pervasiveness and supremacy of the Athman, the interpretation of `Rita', karma and samsara, the assertion of the continuity of existence and the elucidation of the ideals embodied in `Karma', `Jnana' and `Bhakti' involving as they do the possibility of devotion to a personal God-head; all these ideas were regenerated by Adi Sankaracharya. He is rarely superseded in philosophical writings of the world. He vindicated that the Advaita Philosophy is the supreme contribution and achievement of Hinduism. Thinkers and Spiritual leaders of the world have been attracted to Hinduism because of Advaita Philosophy.