What the Brahmasūtras are
The Brahmasūtras are the most difficult of the three canonical texts of Vedanta — the prasthānatrayī (threefold starting point). The Upanishads express the non-dual teaching in narrative, verse, and dialogue. The Bhagavad Gītā expresses it in the context of action, devotion, and crisis. The Brahmasūtras systematise it as philosophy: addressing apparent contradictions between Upanishadic passages, refuting rival schools, and establishing a coherent ontology and epistemology.
Most of the 555 sūtras are extremely terse — often just two or three words — and cannot be understood without a commentary. The sūtras are compressed reminders of positions, not self-explanatory arguments. This is why the major Vedanta schools are distinguished primarily by their commentaries on the Brahmasūtras: Śaṅkara's Brahmasūtra Bhāṣya establishes Advaita; Rāmānuja's Śrī Bhāṣya establishes Viśiṣṭādvaita; Madhva's Brahmasūtra Bhāṣya establishes Dvaita. The same 555 sūtras, read through three different commentarial lenses, produce three incompatible philosophies.
Structure — four chapters
Chapter 1 · Samanvaya — Reconciliation
Brahman as the subject of the Upanishads
Establishes that Brahman is the one topic all the Upanishadic passages are about, despite their surface differences. Resolves apparent contradictions by showing they address different aspects of the same reality.
Chapter 2 · Avirodha — Non-conflict
Refutation of rival schools
Refutes Sāṃkhya, Yoga, Vaiśeṣika, Buddhist, Jain, and other schools' challenges to the Brahman doctrine. Śaṅkara's Bhāṣya on this chapter contains Advaita's most rigorous philosophical arguments against materialism, pluralism, and idealism.
Chapter 3 · Sādhana — Means
The path to liberation
The role of karma, upāsanā (meditation), and jñāna in the path to liberation. Establishes the relationship between lower knowledge (karma-kāṇḍa) and higher knowledge (jñāna-kāṇḍa). Advaita's position: jñāna alone is the direct means; karma produces the preparation.
Chapter 4 · Phala — Fruit
Liberation and its nature
The nature of liberation — both jīvanmukti (while living) and videhamukti (at death). The state of the liberated one. The final sūtra: anavarttī chabdādanupatteḥ — there is no return, as the scriptures declare.
The adhyāsa bhāṣya — Śaṅkara's preamble
Before engaging the first sūtra, Śaṅkara writes a prose preamble to the Brahmasūtra Bhāṣya that has become one of the most studied passages in all of Indian philosophy: the adhyāsa bhāṣya (the superimposition preamble). In it, Śaṅkara introduces his foundational concept: adhyāsa — the mutual superimposition of self and not-self that constitutes the root cause of bondage and the starting point of all Vedantic inquiry.
The preamble argues: all human behaviour presupposes a confusion between the self (the witnessing consciousness) and the not-self (the body, mind, senses). People say "I am fat," "I am angry," "I am blind" — attributing properties of the body and mind to the self. And "my consciousness is active today," "my awareness is clear" — attributing properties of consciousness to what are actually instruments. This two-way superimposition is adhyāsa: the self appears to have the properties of the not-self, and the not-self appears to have the illumination of the self. Vedanta's task is to dissolve this superimposition — not by creating a new state but by the knowledge that reveals it as a superimposition.
The first sūtra
अथातो ब्रह्मजिज्ञासा ।
Now, therefore, the inquiry into Brahman.
Brahmasūtra 1.1.1 · Trans. Gambhirananda
Four words. The first sūtra establishes the occasion for the entire Vedantic inquiry. Atha (now) — after what? After the preliminary qualifications have arisen: viveka, vairāgya, the sixfold inner wealth, mumukṣutva. After the student is ready. Ataḥ (therefore) — because of what? Because the lower knowledge has not and cannot deliver liberation; because karma and ritual produce good results but not the cessation of bondage; because only the knowledge of Brahman addresses the root. Brahma-jijñāsā — the desire to know Brahman. Not the desire to achieve Brahman (it is already present) or to become Brahman (one already is) — but the desire to know, to recognise, what is already the case.
SourceSwami Gambhirananda, trans., Brahma-Sūtra-Bhāṣya of Śrī Śaṅkarācārya (Advaita Ashrama, Calcutta, 2010). For the comparison of schools: S. Radhakrishnan, Indian Philosophy Vol. 2 (Allen & Unwin, 1927); Hajime Nakamura, A History of Early Vedanta Philosophy (Motilal Banarsidass, 1983).