Saving knowledge cannot of course be acquired by worldly experience, but is revealed in the theoretical part (jnana-kanda) of the Vedas, that is to say, in the Upanishads. By this correct knowledge the illusion of the multiplicity of phenomena is dispelled, just as the illusion of a snake when there is only a rope. Two forms of knowledge are, however, distinguished in the Vedanta, a higher (para) and a lower (apara). The former is concerned with the higher and impersonal Brahma (neuter), which is without form or attributes, while the latter deals with the lower and personal Brahma (masculine), who is the soul of the universe, the Lord (içvara) who has created the world and grants salvation. The contradiction resulting from one and the same thing having form and no form, attributes and no attributes, is solved by the explanation that the lower Brahma has no reality, but is merely an illusory form of the higher and only Brahma, produced by ignorance. The doctrines of the Vedanta are laid down in the Brahma-sutras of Badarayana. This text-book, the meaning of which is not intelligible without the aid of a commentary, was expounded in his bhashya by the famous Vedantist philosopher Çankara, whose name is intimately connected with the revival of Brahmanism. He was born in 788 A.D., became an ascetic in 820, and probably lived to an advanced age. There is every likelihood that his expositions agree in all essentials with the meaning of the Brahma-sutras, The full elaboration of the doctrine of Maya, or cosmic illusion, is, however, due to him. An excellent epitome of the teachings of the Vedanta, as set forth by Çankara, is the Vedanta-sara of Sadananda Yogindra. Its author departs from Çankara's views only in a few particulars, which show an admixture of Sankhya doctrine. Among the many commentaries on the Brahma-sutras subsequent to Çankara, the most important is that of Ramanuja, who lived in the earlier half of the twelfth century. This writer gives expression to the views of the Pancharatras or Bhagavatas, an old Vishnuite sect, whose doctrine, closely allied to Christian ideas, is expounded in the Bhagavadgita and the Bhagavata-purana, as well as in the special text-books of the sect. The tenets of the Bhagavatas, as set forth by Ramanuja, diverge considerably from those of the Brahma-sutras on which he is commenting. For, according to him, individual souls are not identical with God; they suffer from innate unbelief, not ignorance, while belief or the love of God (bhakti), not knowledge, is the means of salvation or union with God.