The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
6. Even if we admit (the Sânkhya position refuted in what precedes, it is invalidated by other objections) on account of the absence of a purpose (on the part of the pradhâna).
Even if we, accommodating ourselves to your (the Sânkhya's) belief, should admit what has been disproved in the preceding Sûtra, viz. that the pradhâna is spontaneously active, still your opinion would lie open to an objection 'on account of the absence of a purpose.' For if the spontaneous activity of the pradhâna has, as you say, no reference to anything else, it will have no reference not only to any aiding principle, but also to any purpose or motive, and consequently your doctrine that the pradhâna is active in order to effect the purpose of man will become untenable. If you reply that the pradhâna does not indeed regard any aiding principle, but does regard a purpose, we remark that in that case we must distinguish between the different possible purposes, viz. either enjoyment (on the part of the soul), or final release, or both. If enjoyment, what enjoyment, we ask, can belong to the soul which is naturally incapable of any accretion (of pleasure or pain) 1? Moreover, there would in that case be no opportunity for release 2.--If release, then the activity of the pradhâna would be purposeless, as even antecedently to it the soul is in the
state of release; moreover, there would then be no occasion for the perception of sounds, &c. 1--If both, then, on account of the infinite number of the objects of pradhâna to be enjoyed (by the soul) 2, there would be no opportunity for final release. Nor can the satisfaction of a desire be considered as the purpose of the activity of the pradhâna; for neither the non-intelligent pradhâna nor the essentially pure soul can feel any desire.--If, finally, you should assume the pradhâna to be active, because otherwise the power of sight (belonging to the soul on account of its intelligent nature) and the creative power (belonging to the pradhâna) would be purposeless; it would follow that, as the creative power of the pradhâna does not cease at any time any more than the soul's power of sight docs, the apparent world would never come to an end, so that no final release of the soul could take place 3.--It is, therefore, impossible to maintain that the pradhâna enters on its activity for the purposes of the soul.
372:1 Anâdheyâtisayasya sukhadukhaprâptiparihârarûpâtisayasûnyasyety arthah. Ân. Gi.
372:2 For the soul as being of an entirely inactive nature cannot of itself aim at release, and the pradhâna aims--ex hypothesi--only at the soul's undergoing varied experience.
373:1 I.e. for the various items constituting enjoyment or experience.
373:2 Tritîye#pi katipayasabdâdyupalabdhir vâ samastatadupalabdhir vâ bhoga iti vikalpyâdye sarveshâm ekadaiva muktih syâd iti manvâno dvitîyam pratyâha ubhayârthateti. Ân. Gi.
373:3 The MSS. of Ânanda Giri omit samsârânukkhedât; the Bhâmatî's reading is: Sargasaktyanukkhedavad driksaktyanukkhedât.