Accordingly, these hermit sages, these mystic dreamers, soon came to identify the human soul with God. And the chief end of man was to seek that the stream derived from God should return to its source, and, ceasing to wander through the wilderness of this world, should find repose in the bosom of the illimitable deep, the One, the All. The Brahmans attached the Upanishads to the Veda proper, and they soon came to be regarded as its most sacred part. In this way the influence these treatises have exercised has been immense; more than any other portion of the earlier Hindu writings they have molded the thoughts of succeeding generations. Philosophy had thus begun. [Sidenote: Six philosophic schools.] The speculations of which we see the commencement and progress in the Upanishads were finally developed and classified in a series of writings called the six Sastras or _darsanas_. These constitute the regular official philosophy of India. They are without much difficulty reducible to three leading schools of thought--the Nyaya, the Sankhya, and the Vedanta. Roundly, and speaking generally, we may characterize these systems as theistic, atheistic, and pantheistic respectively. [Sidenote: The Nyaya.] It is doubtful, however, whether the earlier form of the Nyaya was theistic or not. The later form is so, but it says nothing of the moral attributes of God, nor of his government. The chief end of man, according to the Nyaya, is deliverance from pain; and this is to be attained by cessation from all action, whether good or bad. [Sidenote: The Sankhya.] The Sankhya declares matter to be self-existent and eternal. Soul is distinct from matter, and also eternal. When it attains true knowledge it is liberated from matter and from pain. The Sankhya holds the existence of God to be without proof. [Sidenote: The Vedanta.] But the leading philosophy of India is unquestionably the Vedanta. The name means "the end or scope of the Veda;" and if the Upanishads were the Veda, instead of treatises tacked on to it, the name would be correct; for the Vedanta, like the Upanishads, inculcates pantheism. The form which this philosophy ultimately assumed is well represented in the treatise called the Vedanta Sara, or essence of the Vedanta. A few extracts will suffice to exhibit its character. "The unity of the soul and God--this is the scope of all Vedanta treatises." We have frequent references made to the "great saying," _Tat twam_--that is, That art thou, or Thou art God; and _Aham Brahma_, that is, I am God. Again it is said, "The whole universe is God." God is "existence (or more exactly an existent thing[15]), knowledge, and joy." Knowledge, not a knower; joy, not one who rejoices. [Sidenote: It teaches absolute idealism.] Every thing else has only a seeming existence, which is in consequence of ignorance (or illusion). Ignorance makes the soul think itself different from God; and it also "projects" the appearance of an external world.