While the main body of the Vedic hymns are the immediate outgrowth of a worship of the elemental forces of na ture, not a few of the hymns, especially the later ones, evidence a strong tendency toward metaphysical speculation. It is only in the "Upanishads," however, that we meet with the first attempts at some kind of systematic treatment of the great problems of mundane existence, and of the nature of the absolute spirit and its relation to the human mind. The drift of speculative inquiry in those days, as ever afterward, is determined by two cardinal notions which are never ques tioned, and have assumed the force of axioms in Hindu philosophy—viz., the pantheistic notion of the spiritual unity of all sentient beings, and the transmi gration of souls.
Six philosophical systems are recog nized by orthodox Hindus, which fall, however, into three pairs so closely con nected that each pair forms a common school of philosophy—viz., "Mimamsa" and "Vedanta," "Sankhya" and "Yoga," "Nyfiya" and "Vai'seshika." Nothing certain is as yet known as to their date or order. The tenets of each system are propounded in a manual of concise aphorisms, ascribed to the respective founders, and commented on by numerous writers.
The "Vedanta," i. e., "end of the Veda" —as the "Uttara-Mimamsa" ("Later Inquiry") is more commonly called--is the system most closely in accord with the development of religious thought in Brahmanical India. According to this system, God is the omniscient and omnip otent cause, efficient as well as material, of the world: He is both creator and nature; and at the consummation of things all are resolved into Him.
The individual soul is of the same essence as the supreme one; it emanates from Him like one of the sparks that issue from a blazing fire, and ultimately returns to Him. It is not a free agent, but ruled by God; its activity—the source of its suffering—being solely due to its bodily organs.
The "Yoga" school, founded by Patan jali, accepts the speculative system of the Sankhya with its 25 principles; but adds thereto a 26th—viz., the "self de void of attributes," the supreme god of the school, whence the "Yoga" is also called the Theistic Sankhya.