The Caturvyuhopasana is one of the Brahmavidyas like the Sadvidya, Daharavidya etc.
In the third part of the second chapter, the author determines that the spatial ether (Akasa) is a product as there are scriptural statements to prove this. Same could be said of the Vayu etc.
Then he explains that the individual self is not pure consciousness as held by opponents. But he is a knower; and he is inseparably connected with another substance known as knowledge. With the help of this knowledge he is able to find out everything. This knowledge bears to the self the relationship of the rays to the object that emanates those rays.
The next seven Sutras state thus: The self is the doer and not the three qualities, viz., Sattva, Rajas and Tamas; the next two Sutras state thus : The actions of the individual self are all dependent upon the Highest Self. But it should not be said that the Highest Self is responsible for all man's actions, because man alone should choose the first action and the subsequent actions arise as a corollary to his first action.
The first three Sutras of the fourth part of the second chapter state thus: 'The sense organs are all products in the same way as the spatial ether (Akasa) etc. because there is the scriptural statement.' The Sat, alone, my dear, was in the beginning!
The next two Sutras state thus: 'The sense-organs are eleven in number and they move with the self.'
Then the topic of the Prana is elaborately dealt with in this part.
III Adhyaya. The first seven Sutras of the first part of the third chapter determine this point: 'The individual self when he moves from one body to another, goes enveloped by the rudiments of the elements '.
