Atman,

in Buddhist philosophy, is the noumenon of one’s own self. Not the Ego, but the ego divested of all that is objective; the “spark of heavenly flame.”

“The unseen and unperceivable, which was formerly called the soul, was now called the self, Atman. Nothing could be predicated of it except that it was, that it perceived and thought, and that it must be blessed.” — Max Muller: Nineteenth Century, May, 1893, p. 777.