The monistic theory of the early Upanishads, which identified the individual soul with Brahma, aroused the opposition of the rationalistic founder of the Sankhya system, Kapila, who, according to Buddhist legends, was pre-Buddhistic, and whose doctrines Buddha followed and elaborated. His teaching is entirely dualistic, admitting only two things, both without beginning and end, but essentially different, matter on the one hand, and an infinite plurality of individual souls on the other. An account of the nature and the mutual relation of these two, forms the main content of the system. Kapila was, indeed, the first who drew a sharp line of demarcation between the two domains of matter and soul. The saving knowledge which delivers from the misery of transmigration consists, according to the Sankhya system, in recognising the absolute distinction between soul and matter. The existence of a supreme god who creates and rules the universe is denied, and would be irreconcilable with the system. For according to its doctrine the unconscious matter of Nature originally contains within itself the power of evolution (in the interest of souls, which are entirely passive during the process), while karma alone determines the course of that evolution. The adherents of the system defend their atheism by maintaining that the origin of misery presents an insoluble problem to the theist, for a god who has created and rules the world could not possibly escape from the reproach of cruelty and partiality. Much stress is laid by this school in general on the absence of any cogent proof for the existence of God. The world is maintained to be real, and that from all eternity; for the existent can only be produced from the existent. The reality of an object is regarded as resulting simply from perception, always supposing the senses of the perceiver to be sound. The world is described as developing according to certain laws out of primitive matter (prakriti or pradhana). The genuine philosophic spirit of its method of rising from the known elements of experience to the unknown by logical demonstration till the ultimate cause is reached, must give this system a special interest in the eyes of evolutionists whose views are founded on the results of modern physical science.