primal cause, he is the eternal law, he is the essence of everything, he is nature, he is not a separate entity. Liberation comes to those who know Supreme Being is present as the Universal Spirit and Principle, just as they know butter is present in milk. Such realization, claims Svetasvatara, come from self-knowledge and self-discipline; and this knowledge and realization is liberation from transmigration, the final goal of the Upanishad.

Starting with the middle Upanishad era, moksha - or equivalent terms such as mukti and kaivalya