The Brahma Sūtras proceed from the conviction that the many Upaniṣads, despite their diversity of language and imagery, are all pointing toward a single subject: Brahman, the ultimate reality that is also the inner Self. To draw out this unity, they employ a method of systematic harmonization (samanvaya), examining each passage in light of its context, its opening and closing statements, the frequency of its key ideas, the uniqueness of its teaching, and the nature of the result it promises. Teachings that lead to liberation are treated as expressing the highest purport, while those that concern ritual or limited worldly results are seen as preparatory. In this way, scattered references to Brahman as cause, as inner Self, as the ground of liberation, are gathered into a single, coherent vision.

A crucial part of this harmonizing work is distinguishing primary from secondary meanings. Statements that reveal Brahman’s nature as the non-dual ground of existence and consciousness are taken as primary, while more concrete descriptions—various attributes, forms, or meditations—are often treated as symbolic or provisional, meant to guide different kinds of seekers. The Sūtras also recognize that some Upaniṣadic passages emphasize difference—between individual self and Lord, or between world and Brahman—while others stress non-difference, such as the great sayings that declare identity with the Absolute. These are reconciled by assigning them to different standpoints: an empirical level where distinctions operate, and an ultimate level where only non-dual Brahman is affirmed.

Through this lens, the Brahma Sūtras organize the Upaniṣadic material into a structured Vedānta: teachings on Brahman as the cause of the universe, the nature and status of the individual self, the reality of the world, the means of knowledge and contemplation, and the fruit of liberation. Apparent contradictions are addressed by clarifying whether a passage is literal or metaphorical, central or illustrative, absolute or pedagogical. At the same time, rival interpretations that would fragment this unity—such as purely ritualistic readings or dualistic cosmologies—are examined and set aside in favor of a Brahman-centered understanding consistent with the totality of śruti. The result is a unified metaphysical and soteriological framework in which the many voices of the Upaniṣads are heard as variations on a single, liberating theme.