Traditional commentators on the Upanishads frequently describe the world as an illusion that needs to be abandoned in order to achieve the spiritual realisation of the Immutable, the Infinite, the Brahman. Consciously or unconsciously, they create a division between the outer life in the world and the inner life of the spiritual aspirant. It is fully understandable that, as an antidote to fixation on the objects of senses and the life of ego and desire, that spiritual teachers focused their students on the inner life at the expense of all else. At some point, however, the Oneness of all creation, and the intention of the divine in the manifestation of the cosmos needs to be brought back into view, and these two extremes harmonised. The Taittiriya Upanishad implies this in its focus both on achieving spiritual realisation through intense concentrated practice, tapasya, and its statement of results to be attained, which includes various evidences of success and achievement in the manifested world.
Sri Aurobindo observes: “The Supreme is not something aloof and shut up in itself. It is not a mere indefinable, prisoner of its own featureless absoluteness, impotent to define, create, know itself variously, eternally buried in a sleep or a swoon of self-absorption. The Highest is the Infinite and the Infinite contains the All. Whoever attains the highest consciousness, becomes infinite in being and embraces the All.”
“To make this clear the Upanishad has defined the Brahman as the Truth, Knowledge, Infinity and has defined the result of the knowledge of Him in the secrecy, in the cave of being, in the supreme ether as the enjoyment of all its desires by the soul of the individual in the attainment of its highest self-existence.”
“Our highest state of being is indeed a becoming one with Brahman in his eternity and infinity, but it is also an association with him in delight of self-fulfilment, …. And that principle of the Eternal by which this association is possible, is the principle of his knowledge, his self-discernment and all-discernment, the wisdom by which he knows himself perfectly in all the world and all beings….”
“Delight of being is the continent of all the fulfilled values of existence which we now seek after int he forms of desire. To know its conditions and possess it purely and perfectly is the infinite privilege of the eternal Wisdom.”