Advaita Vedānta is a major school of Hindu philosophy that teaches radical non‑dualism: there is only one absolute, unchanging reality called Brahman, and the true self, Ātman, is not other than that reality. Brahman is described as the sole, formless, infinite ground of all existence, while the individual self, when stripped of body, mind, and ego, is revealed as that very same Brahman. This identity is expressed in the great saying “tat tvam asi” – “That thou art” – which points to the unity of the innermost self with ultimate reality. From this standpoint, all distinctions between subject and object, self and other, are ultimately false, resting on a misapprehension of what is truly real.

The world of multiplicity and change is explained through the concept of māyā, the power by which the one appears as many, giving rise to a perceived universe of separate entities and experiences. This appearance is not absolutely real; it is sustained by avidyā, or ignorance, which makes one take the body‑mind complex to be the self and the phenomenal world to be ultimately true. Because of this ignorance, there arises the sense of limitation, bondage, and separation from Brahman, even though, from the standpoint of Advaita, such separation never actually occurs. The spiritual problem, therefore, is not the loss of unity but the failure to recognize a unity that is always already the case.

Liberation, or mokṣa, in this vision is not the acquisition of something new but the removal of ignorance through direct knowledge (jñāna) of one’s real nature as Brahman. This realization dissolves the superimposed sense of individuality and reveals that the self was never bound in the first place. The traditional means to this realization include listening to the teachings of the Upaniṣads, Bhagavad Gītā, and Brahma Sūtras (śravaṇa), reflecting deeply on their meaning (manana), and contemplative assimilation until insight becomes steady (nididhyāsana). Self‑inquiry (ātma‑vichāra) and guidance from a qualified teacher are emphasized as practical supports for this transformation of understanding.

Historically, Advaita Vedānta is rooted in the Upaniṣads and was later systematized by teachers such as Gauḍapāda and, especially, Śaṅkarācārya, whose commentaries shaped its classical formulation. Under this framework, Advaita stands as a rigorous philosophical articulation of the claim that there is only one non‑dual consciousness, Brahman, and that the true self of every being is identical with that absolute reality.