The Vedanta Sutras, commentary by Sankaracharya (SBE34), tr. by George Thibaut  at sacred-texts.com
2. And on account of (the impossibility of) activity.
Leaving the arrangement of the world, we now pass on to the activity by which it is produced.--The three gunas, passing out of the state of equipoise and entering into the condition of mutual subordination and superordination, originate activities tending towards the production of particular effects.--Now these activities also cannot be ascribed to a non-intelligent pradhâna left to itself, as no such activity is seen in clay and similar substances, or in chariots and the like. For we observe that clay and the like, and chariots--which are in their own nature non-intelligent--enter on activities tending towards particular effects only when they are acted upon by intelligent beings such as potters, &c. in the one case, and horses and the like in the other case. From what is seen we determine what is not seen. Hence a non-intelligent cause of the world is not to be inferred because, on that hypothesis, the activity without which the world cannot be produced would be impossible.
But, the Sânkhya rejoins, we do likewise not observe activity on the part of mere intelligent beings.--True; we however see activity on the part of non-intelligent things such as chariots and the like when they are in conjunction with intelligent beings.--But, the Sânkhya again objects, we never actually observe activity on the part of an intelligent
being even when in conjunction with a non-intelligent thing.--Very well; the question then arises: Does the activity belong to that in which it is actually observed (as the Sânkhya says), or to that on account of the conjunction with which it is observed (as the Vedântin avers)?--We must, the Sânkhya replies, attribute activity to that in which it is actually seen, since both (i.e. the activity and its abode) are matter of observation. A mere intelligent being, on the other hand, is never observed as the abode of activity while a chariot is. The 1 existence of an intelligent Self joined to a body and so on which are the abode of activity can be established (by inference) only; the inference being based on the difference observed between living bodies and mere non-intelligent things, such as chariots and the like. For this very reason, viz. that intelligence is observed only where a body is observed while it is never seen without a body, the Materialists consider intelligence to be a mere attribute of the body.--Hence activity belongs only to what is non-intelligent.
To all this we--the Vedântins--make the following reply.--We do not mean to say that activity does not belong to those non-intelligent things in which it is observed; it does indeed belong to them; but it results from an intelligent principle, because it exists when the latter is present and does not exist when the latter is absent. Just as the effects of burning and shining, which have their abode in wood and similar material, are indeed not observed when there is mere fire (i.e. are not due to mere fire; as mere fire, i.e. fire without wood, &c., does not exist), but at the same time result from fire only as they are seen when fire is present and are not seen when fire is absent; so, as the Materialists also admit, only intelligent bodies are observed
to be the movers of chariots and other non-intelligent things. The motive power of intelligence is therefore incontrovertible.--But--an objection will be raised--your Self even if joined to a body is incapable of exercising moving power, for motion cannot be effected by that the nature of which is pure intelligence.--A thing, we reply, which is itself devoid of motion may nevertheless move other things. The magnet is itself devoid of motion, and yet it moves iron; and colours and the other objects of sense, although themselves devoid of motion, produce movements in the eyes and the other organs of sense. So the Lord also who is all-present, the Self of all, all-knowing and all-powerful may, although himself unmoving, move the universe.--If it finally be objected that (on the Vedânta doctrine) there is no room for a moving power as in consequence of the oneness (aduality) of Brahman no motion can take place; we reply that such objections have repeatedly been refuted by our pointing to the fact of the Lord being fictitiously connected with Mâyâ, which consists of name and form presented by Nescience.--Hence motion can be reconciled with the doctrine of an all-knowing first cause; but not with the doctrine of a non-intelligent first cause.
368:1 The next sentences furnish the answer to the question how the intelligent Self is known at all if it is not the object of perception.--Pratyakshatvâbhâve katham âtmasiddhir ity âsankya anumânâd ity âha, pravrittîti. Anumânasiddhasya ketanasya na pravrittyâsrayateti darsayitum evakârah. Katham anumânam ity apekshâyâm tatprakâram; sûkayati kevaleti. Vailakshanyam prânâdimattvam. Ân. Gi.