Ataman, the One and Undifferentiated, which by the manifold application of its powers produces, the dual and non dual experiences [waking/dream/deep sleep] and, in the end, withdraws the three states into itself, is indeed the self—luminous.
The Maker of all the three states, self—luminous and all—pervading, Ataman dwells always in the three states as its formless clay and witness. Ataman is revealed by the negative way, discriminative wisdom and the Knowledge of Unity based upon reflection. The one who know Ataman is the true self becomes one with the immortal self.
When there is no ignorance, there is no day or night, neither being nor none—being; the pure Ataman alone exists. That immutable Reality is the meaning of "Ataman. From it has proceeded the non dual wisdom.
No one can grasp Ataman as separate entity apart from duality because it is the formless clay and the witness of the experience of duality thus it cannot be grasped as above, across, or in the middle.
Its form is not an object of vision; no one beholds it with the eyes. They who, through pure intellect and the Knowledge of Unity based upon reflection, realize Ataman as the true self becomes one with the immortal.
