In Advaita Vedānta, the relation between Ātman and Brahman is not one of similarity, part and whole, or creator and creature, but of complete identity. Ātman, the innermost Self, is understood as pure, witnessing consciousness, distinct from body, mind, and ego. Brahman, the ultimate reality, is the infinite, absolute ground of all that appears, often characterized as existence-consciousness-bliss. What seems to be an individual center of awareness is, in truth, nothing other than that same undivided reality.

This identity is articulated in the mahāvākyas, the “great sayings” of the Upaniṣads, such as “Tat tvam asi” (“That thou art”) and “Aham Brahmāsmi” (“I am Brahman”). These declarations do not propose a future union to be attained, but point to an already-present fact about the nature of the Self. The apparent distinction between the individual self (jīva) and the absolute is attributed to avidyā, or ignorance, and to māyā, the power by which multiplicity and separation seem to arise. Under the spell of this ignorance, consciousness appears fragmented into many selves and a world of objects.

Advaita holds that this fragmentation has no ultimate reality; it is a superimposition upon the one non-dual consciousness. The world of multiplicity, while experientially compelling, is regarded as dependent and appearance-like, whereas Brahman alone enjoys absolute reality. Through jñāna, liberating knowledge, the veil of ignorance is removed, and it is realized that the true nature of the seeker has never been other than Brahman. The spiritual journey, from this standpoint, is not a movement toward something new, but a recognition of what has always been the case: Ātman just is Brahman, and there is only one reality appearing as many.