Padmapāda, in his commentary upon Sankara’s introduction to the Brahmasūtras, explains that there are two factors involved in the very notion of ‘I’: there is the ‘not this’ (anidam amid) aspect which is the Self and there is the ‘this’ (idama śa) or objectified aspect which is the ego and which consists of all cognitive states including the self-reflexive cognition of ‘me’, the historical person who has an identification with a set of memories, who has a particular personality and who carries a certain sense of self-worth, etc. Padmapāda says that the idea of ‘I’, as consisting of both these aspects, is a matter for one’s own careful consideration. Thus in the Advaita of Śa kara and Padmapāda the ascertainment of the essential Self is not so much a matter of a ‘mystical’ experience occurring in time as a matter of enquiry consisting of the careful and concentrated inspection of and reflection upon one’s ordinary experience. Through the discrimination of the outward or objectified factors from I, Advaitins conclude that the true Self can only be Pure Consciousness or Pure Experience (anubhūtisvarūpa). Thus there can be no ‘objective’ experience of the Self because Consciousness itself is Experience.
Michael Comans, "Later Vedānta" (in Brian Carr & Indira Mahalingam edd. Companion Encyclopedia of Asian Philosophy. London: Routledge, 2001. 1