they are frequently inconsistent. But there are some ideas which are more or less present in all of them. They regard Brahma as absolute and infinite Thought and Being at once, and as such it is one with the consciousness, soul or self, of the individual when the latter rids himself of the illusion of a manifold universe and realises his unity with Brahma. Moreover, Brahma is bliss — the joy of wholly perfect and self-satisfied thought and being. Since Brahma as universal Soul is really identical with each individual soul or ātmā, and vice versa, it follows that each individual soul contains within itself, qua Brahma, the whole of existence, nature, gods, mankind, and all other beings; it creates them all, and all depend upon it. Our Aupanishadas are thorough-going idealists.
Another new idea also appears for the first time in the early Upanishads, and one that henceforth will wield enormous influence in all Indian thought. This is the theory of karma and saṃsāra, rebirth of the soul in accordance with the nature of its previous works. Before the Upanishads we find no evidence of this doctrine: the nearest approach to it is in some passages of the Brāhmaṇas which speak of sinful men dying again in the next world as a punishment for their guilt. But in the Upanishads the doctrine appears full-fledged, and it is fraught with consequences of immense importance. Saṃsāra
