The Brahma Sūtras present Brahman as the ultimate reality, the source from which the universe arises, in which it is sustained, and into which it finally dissolves. This Brahman is pure existence-consciousness, infinite and self-existent, not a product or effect of anything else. In its highest truth Brahman is without limiting attributes, beyond the grasp of ordinary perception and inference, yet the same reality also appears as the personal Lord, the intelligent cause and controller of the cosmos. The Sūtras thus affirm Brahman as both the efficient and the material cause of the universe, carefully distinguishing this view from positions that posit primordial matter, individual souls, or void as the ultimate ground.

Ātman, as understood in this tradition, is the innermost Self, the witness-consciousness that underlies all experience yet is distinct from body, mind, senses, and vital forces. It is eternal, unchanging, and not truly the doer of actions, though it appears so due to ignorance. The Brahma Sūtras identify this Ātman with the very Brahman that is the cause of the universe, gathering and harmonizing Upaniṣadic statements that speak of the inner Self and the cosmic Lord. Any perceived difference between the individual self (jīva) and Brahman is traced to limiting adjuncts such as body, mind, and ignorance, rather than to any real division in consciousness itself.

From this standpoint, there is in essence one non-dual reality: Brahman-Ātman, existence-consciousness-infinity, which is also spoken of as bliss. The manifold world and the plurality of selves are understood as appearances grounded in ignorance (avidyā), effective at the empirical level yet not ultimately altering the unity of consciousness. Liberation, therefore, is not the production of a new state but the direct knowledge that one’s own innermost Self has always been none other than Brahman. This realization, expressed in the great Upaniṣadic sayings such as “tat tvam asi” and “ahaṃ brahmāsmi,” dissolves the illusion of separation and reveals the ever-free nature of the Self that the Brahma Sūtras labor to articulate and defend.