Brahmasutra consists of 4 chapters (Adhyaaya). Each adhyaaya is sub-divided into 4 sections (paada). There are 16 paadas totally and each paada is sub-divided according to subject matter (Adhikaranam). There are totally 191 adhikaranams. They are not uniform and differ from paada to paada. All topics are collected from Vedanta, especially the 10 Upanishads. Each adhikaranam is sub-divided into various sutraani. There are 555 Sutrani totally.The topics discussed in these adhyaayas can be broadly classified into four topics.

Adhyaaya I ( Samanvaya Adhyaaya ) - Samanvaya meaning consistency, is a technical word occurring in Memamsa Shastram. In the entire first adhyaaya Vyasacharya presents Samanvaya as a proof to establish that Brahman is the central theme of the Upanishads in contrast to the other systems of philosophy that propound Karma (Action) as the central theme.

Adhyaaya II ( Avirodha Adhyaaya) - Avirodha can be translated as non-contradiction. Here, Vyasa establishes that Brahmavidya is free from all contradictions. He establishes that :.

• The different statements of the Shruti do not contradict each other.
• The statements of the Smritis are consistent with those of the Shruti.
• The statements of the Shruti are not against logic (Yukti).

Vyasa refutes the Naastika Darshanams also and shows the presence of logical contradictions in other darshanams.

Adhyaaya III (Sadhana Adhyaya) - All sadhanas, the preparatory disciplines or means for gaining Brahmavidya are discussed.

Adhyaaya IV (Phala Adhyaya) - It deals with the fruit (phalam) of Brahmavidya that is MOKSHA.

Definitions of the following are necessary for better understanding.

1. Sutram:
   Sutra literally means thread.
   The following sanskrit verse defines a sutra
   

   Alpaaksharamasamdigdhe saaravat vishvatomukham, Asto Bhamanavadhyam ca sutram sutra vido viduhu.

   
   A sutram should be.
   

   • Concise
   • Clear
   • Convey the essence of an Upanishadic Statement
   • Multi-faceted. (if possible)
   • Without glorifications
   • Faultless (There should be no defects in the words and meanings).

   
   The Brahmasutra serves as a thread to the Upanishadic ideas which are like beeds.

2. Bhashyam:
   

   Vaakyaihi sutra anusaribhihi sva padaani ca varnyante, Bhashyam bhasha vido vidu:

   
   A Bhashyam (commentary) explains every word in the same order as it occurs in the sutra, and elucidates technical words in the Bhashyam.

3. Adhikaranam:
   

   Vishayo samshayashcaiva poorva pakshastathontaram. Sangatishceti panchaagam shastraadhikaranam smrutam.

   
   It consists of 5 factors.
   

   • Vishaya , subject matter (generally taken from Upanishads).
   • Samshaya, Doubts in a particular Upanishadic statement are presented but what is evident need not be enquired into.
   • Poorva Paksha, Views of the non-vedantins with their reasons.
   • Siddhanta, Vedantic conclusion which is established after refuting all possible objections. It logically refutes others views and logically established the statement.
   • Sangati, Connection between two topics.

Brahmasutra is a NYAYA PRASTHAANA which uses Nyaya or Reasoning to establish the Upanishadic teachings.

A discusion on Anumanam follows...