The Vedanta Sutras of Badarayana, Commentary by Sankara (SBE38), tr. by George Thibaut  at sacred-texts.com
REVERENCE TO THE HIGHEST SELF!
1. (The cognitions) intimated by all the Vedânta-texts (are identical), on account of the non-difference of injunction and so on.
In the preceding part of this work we have explained the nature of the object of cognition, i.e. Brahman. We now enter on the discussion of the question whether the cognitions of Brahman, which form the subject of the different Vedânta-texts, are separate cognitions or not.
But, an objection may here be raised, so far we have determined that Brahman is free from all distinctions whatever, one, of absolutely uniform nature like a lump of salt; hence there appears to be no reason for even raising the question whether the cognitions of Brahman are separate cognitions or constitute only one cognition. For as Brahman is one and of uniform nature, it certainly cannot be maintained that the Vedânta-texts aim at establishing a plurality in Brahman comparable to the plurality of works (inculcated by the karmakânda of the Veda). Nor can it be said that although Brahman is uniform, yet it may be the object of divers cognitions; for any difference in nature between the cognition and the object known points to a mistake committed. If, on the other hand, it should be assumed that the different Vedânta-texts aim at teaching different cognitions of Brahman, it would follow that only one cognition can be the right one while all others are mistaken, and that would lead to a general distrust of all Vedânta.--Hence the question whether each individual Vedânta-text teaches a separate cognition of Brahman or not cannot even be raised.--Nor, supposing that question were raised after all, can the non-difference of the cognition of Brahman be demonstrated (as the Sûtra attempts) on the ground that all Vedânta-texts are equally injunctions, since the cognition of Brahman is not of the nature of an injunction. For the teacher has proved at
length (I, 1, 4) that the knowledge of Brahman is produced by passages which treat of Brahman as an existing accomplished thing and thus do not aim at enjoining anything.--Why then begin at all this discussion about the difference or non-difference of the cognitions of Brahman?
To all this we reply that no objection can be raised against a discussion of that kind, since the latter has for its object only the qualified Brahman and prâna and the like. For devout meditations on the qualified Brahman may, like acts, be either identical or different. Scripture moreover teaches that, like acts, they have various results; some of them have visible results, others unseen results, and others again--as conducive to the springing up of perfect knowledge--have for their result release by successive steps. With a view to those meditations, therefore, we may raise the question whether the individual Vedânta-texts teach different cognitions of Brahman or not.
The arguments which may here be set forth by the pûrvapakshin are as follows. In the first place it is known that difference may be proved by names, as e.g. in the case of the sacrificial performance called 'light' (gyotis) 1. And the cognitions of Brahman which are enjoined in the different Vedânta-texts are connected with different names such as the Taittirîyaka, the Vâgasaneyaka, the Kauthumaka, the Kaushîtaka, the Sâtyâyanaka, &c.--In the second place the separateness of actions is proved by the difference of form (characteristics; rûpa). So e.g. with reference to the passage, 'the milk is for the Visvedevas, the water for the vâgins.' 2
Now similar differences of form are met with in the Vedânta-texts; the followers of one Sâkhâ, e.g. mention, in the chapter called 'the knowledge of the five fires,' a sixth fire, while other Sâkhâs mention five only; and in the colloquy of the prânas some texts mention a lesser, others a greater number of organs and powers of the body.--In the third place differences in qualifying particulars (dharma) are supposed to prove difference of acts, and such differences also are met with in the Vedanta-texts; only in the Mundaka-Upanishad. e.g. it is said that the science of Brahman must be imparted to those only who have performed the rite of carrying fire on the head (Mu. Up. III, 2, 10).--In the same way the other reasons which are admitted to prove the separateness of actions, such as repetition and so on, are to be applied in a suitable manner to the different Vedânta-texts also.--We therefore maintain that each separate Vedânta-text teaches a different cognition of Brahman.
To this argumentation of the pûrvapakshin we make the following reply.--The cognitions enjoined by all the Vedânta-texts are the same, owing to the non-difference of injunction and so on. The 'and so on' refers to the other reasons proving non-difference of acts which are enumerated in the Siddhânta-sûtra of the adhikarana treating of the different Sâkhâs (Pû. Mî. II, 4, 9, '(the act) is one on account of the non-difference of connexion of form, of injunction, and of name'). Thus, as the agnihotra though described in different Sâkhâs is yet one, the same kind of human activity being enjoined in all by means of the words, 'He is to offer;' so the injunction met with in the text of the Vâgasaneyins (Bri. Up. VI, 1, 1), 'He who knows the oldest and the best,' &c., is the same as that which occurs in the text of the Khandogas, 'He who knows the first and the best' (Kh. Up. V, 1, 1). The connexion of the meditation enjoined with its aim is likewise the same in both texts, 'He becomes the first and best among his people.' In both texts again the cognition enjoined has the same form. For in both the object of knowledge is the true nature of the prâna which is characterised by
certain qualities such as being the first and best, and just as the material and the divinity constitute the form of the sacrifice, so the object known constitutes the form of the cognition. And finally both cognitions have the same name, viz. the knowledge of the prâna.--For these reasons we declare that the different Vedânta-texts enjoin identical cognitions.--A similar line of reasoning applies to other cognitions which are met with in more than one Vedânta-text, so e.g. to the knowledge of the five fires, the knowledge of Vaisvânara, the knowledge of Sândilya. and so on.--Of the apparent reasons on the ground of which the pûrvapakshin above tried to show that the meditations are not identical but separate a refutation is to be found in the Pûrvâ Mîmâmsâ-sûtras II, 4, 10 ff.
The next Sûtra disposes of a doubt which may remain even after the preceding discussion.
185:1 See the samgñâkritakarmabhedâdhikarana, Pû. Mî. Sû. II, 2, 22, where the decision is that the word gyotis (in 'athaisha gyotir' &c.) denotes not the gyotishtoma but a separate sacrificial performance.
185:2 See Pû. Mî. Sû. II, 2, 23. The offering of water made to the divinities called vâgin is separate from the offering of milk to the Visvedevas; for the material offered as well as the divinity to which the offering is made (i.e. the two rûpa of the sacrifice) differs in the two cases.