CHAPTER THREE: SADHANA ADHYAYA
Section 3: Anyathatvadhikaranam: Topic 3 (Sutras 6-8)

Those Vidyas with different subject-matter are separate, even if there may be some similarities.
Anyathatvam sabdaditi chennaviseshat III.3.6 (365)
If it be said (that the Udgitha Vidya of the Brihadaranyaka Upanishad and that of the Chhandogya Upanishad) are different on account of (difference in) texts; we deny this on the ground of their non-difference (as regards essentials).
Anyathatvam: there is difference; Sabdat: on account of (difference in) texts; Iti: so; Chet: if; Na: not; Aviseshat: on account of non-difference (as regards essentials).
This Sutra represents the view of the Purvapakshin or the opponent. The opponent tries to establish that the two Vidyas are one.
The Sutra consists of two parts namely, a supposed objection to the objector's view and its refutation by the objector to strengthen his case. The supposed objection is "Anyathatvam sabdaditi chet" and the reply is "Naviseshat".
It is said in the Vajasaneyaka (I.3.1), "The Devas said, 'Well, let us defeat the Asuras at the sacrifices by means of the Udgitha!' They said to speech: 'sing for us.' The speech said 'yes'."
The speech and the other Pranas were pierced by the Asuras with evil. They were not able to do what was expected from them. Thereupon the Devas appointed the Chief Prana, and said to the breath in the mouth 'sing for us'. The breath said 'yes' and sang.
There is a similar story in Chhandogya Upanishad I.2. The Devas took the Udgitha. They thought they would overcome the Asuras with it. The other Pranas were pierced with evil and thus vanquished by the Asuras. Thereupon the Devas went to the Chief Prana. "Then comes the Chief Prana. On that they meditated as Udgitha."
Both these passages glorify the chief Prana. Hence it follows that they both are injunctions of a meditation on the Prana. A doubt arises now whether the two Vidyas are separate Vidyas or one Vidya only.
The Purvapakshin holds that the two Vidyas have to be considered as one. It may be objected that they cannot be one on account of the difference in texts. The Vajasaneyins represent the chief vital air as the producer of the Udgitha, "Do thou sing out for us"; while the Chhandogyas speak of it as itself being the Udgitha, "On that they meditated as Udgitha". How can this divergence be reconciled with the assumption of the unity of the Vidyas?
But this is not acceptable because there is unity as regards a great many points. Both texts relate that the Devas and the Asuras were fighting; both at first glorify speech and the other Pranas in their relation to the Udgitha and thereupon finding fault with them pass on to the chief Prana; both tell how through the strength of the latter, the Asuras were vanquished.
The difference pointed out, is not important enough to bring about a separation of the two Vidyas.
The text of the Vajasaneyaka also coordinates the chief Prana and the Udgitha in the clause, "He is Udgitha" (Bri. Up. I.3.23). We therefore have to assume that in the Chhandogya also the chief Prana has secondarily to be looked upon as the producer of the Udgitha.
The two texts thus constitute one Vidya only. There is unity of Vidyas on the grounds given in Sutra III.3.1.
Na va prakaranabhedatparovariyastvadivat III.3.7 (366)
Or rather there is no (unity of the Vidyas) owing to the difference of subject matter even as (the meditation on the Udgitha) as the highest and greatest (i.e., Brahman) (is different from the meditation on the Udgitha as abiding in the eye etc.).
Na: not; Va: certainly; Prakaranabhedat: on account of difference in subject matter; Parovariyastvadivat: even as (the meditation on the Udgitha) as the highest and great (Brahman) (is different).
The objection raised in the preceding Sutra is refuted.
The Sutra refutes the former view and establishes that the two Vidyas, in spite of similarity in many points, are different owing to difference in subject matter.
In the Chhandogya, Omkara is said to be a limit of Udgitha and so such Omkara has to be regarded as Prana. In the other the singer of Udgitha, the Udgatri is called Prana. Therefore the two Vidyas are different just as the Upasana of Udgitha as the Infinite and Supreme (Parovariya) (Chh. Up. I.9.2). "This is indeed the highest and greatest" is different from the Upasana of Udgitha as golden in form and as being in the eye and in the sun (Chh. Up. I.6).
In the Chhandogya only a part of the Udgitha (hymn), the syllable OM is meditated upon as Prana "Let one meditate on the syllable OM of the Udgitha" (Chh. Up. I.1.1). But in the Brihadaranyaka the whole Udgitha hymn is meditated upon as Prana (I.3.2). Hence the two Vidyas cannot be one owing to this difference in the object of meditation.
The special features of different Vidyas are not to be combined even when the Vidyas belong to one and the same Sakha; much less then when they belong to different Sakhas.
Samjnataschet taduktamasti tu tadapi III.3.8 (367)
If it be said (that the Vidyas are one) on account of (the identity of) name; (we reply that) that is explained (already); moreover that (identity of name) is (found in the case of admittedly separate Vidyas).
Samjnatah: on account of the name (being same); Chet: if; Tat: that; Uktam: has already been answered; Asti: is, exists; Tu: but; Tat: that; Api: even, also.
An argument against the preceding Sutra is refuted.
The word 'tu' (but), removes the doubt raised above.
You cannot call them identical merely because they have the same name. The subject matter differs. This has already been established in the last Sutra. For instance Agnihotra and Darsapurnamasa are separate and yet have the same name, viz., Kathaka as they are described in the book called Kathaka. Even the Udgitha Vidya of Chh. Up. I.6 and Chh. Up. I.9.2 are different Vidyas.