Non-dualism in Advaita Vedānta teaches that reality is ultimately one, without a second, and that this one reality is Brahman, the absolute, formless, attributeless consciousness. The individual self, or Ātman, is not merely related to Brahman, nor a part or reflection of it, but is asserted to be identical with Brahman itself. This identity is expressed in the great saying “tat tvam asi” – “That thou art” – indicating that the innermost Self is the very same reality that appears as the cosmos. From this standpoint, Brahman alone is absolutely real, while all multiplicity and difference are appearances within that single reality.

The experience of being a separate individual, distinct from the world and from the divine, is attributed to ignorance (avidyā) and the power of illusion (māyā). Through māyā, Brahman seems to manifest as a world of diverse objects, beings, and experiences, much as a rope may be mistaken for a snake in dim light. Advaita acknowledges that this world of diversity has empirical validity, yet it does not possess the same absolute status as Brahman. Diversity and change belong to the realm of appearance, while the substratum underlying every experience is the one, unchanging consciousness.

Non-dualism thus does not deny the practical reality of distinctions in everyday life; rather, it reinterprets them as dependent on, and ultimately resolved into, the single reality of Brahman. The sense of “I” versus “world,” or “self” versus “God,” arises from identifying consciousness with body, mind, and ego, instead of recognizing it as the limitless Self. Liberation (mokṣa) is described as self-realization through direct knowledge (jñāna) that one’s true nature is none other than Brahman. When this knowledge becomes firm, the superimposed duality falls away, and what remains is the recognition that only non-dual consciousness is ultimately real.