Adi Shankaracharya presents Brahman as the one, absolute reality that underlies and transcends all phenomena. Brahman is characterized as Sat–Chit–Ananda: pure existence, pure consciousness, and pure bliss, not as added properties but as its very essence. In its highest truth, this reality is Nirguna and Nirakara—without attributes, qualities, or form—and therefore beyond the grasp of ordinary thought and language. It is eternal, infinite, and unchanging, untouched by the multiplicity and flux that appear within experience. From the standpoint of ultimate reality (paramārthika), only this Brahman truly is; all distinctions and dualities are ultimately sublated in its non-dual nature.

In relation to the individual, Shankaracharya teaches the essential identity of Ātman and Brahman. The inner self of every being is not other than that absolute reality, a truth encapsulated in mahāvākyas such as “tat tvam asi.” The sense of separation between the individual soul and Brahman arises through avidyā or māyā, a beginningless ignorance that superimposes limitation upon the limitless. Liberation (mokṣa) is nothing new that is produced; it is the direct realization of this ever-existing identity, the removal of ignorance that veils what is already the case. Thus, spiritual practice is oriented toward the dissolution of false identification rather than the acquisition of some external state.

Shankaracharya also allows for a pedagogical distinction between Nirguna Brahman and Saguna Brahman. When Brahman is viewed through the conditioning power of māyā, it appears as Īśvara, the personal God endowed with attributes, who functions as both the material and efficient cause of the universe. This Saguna Brahman is accepted as empirically real and serves as a valid object of devotion, worship, and meditation for those who are not yet prepared for the formless truth. Yet, from the higher standpoint, even this divine form is an appearance upon the attributeless Brahman, which alone remains absolutely real. The world and its plurality, including the worshipper and the worshipped, are ultimately understood as superimpositions upon that one, undivided consciousness.