Ch 18, Sh 48 continued-1, Bhagawad Gita, Shankar Bhashya

Opponent: Well, is it that one should not abandon action because it cannot be given up completely, or is it because evil [Evil resulting from discarding daily obligatory duties.] follows from the giving up of the duty to which one is born?
Counter-objection: What follows from this?
Opponent: If it be that the duty to which one is born should not be renounced because it is impossible to relinquish it totally, then the conclusion that can be arrived at is that complete renunciation (of duty) is surely meritorious!
Counter-objection: Truly so. But, may it not be that total relinquishment is itself an impossibility? Is a person ever-changeful like the gunas of the Sankhyas, or is it that action itself is the agent, as it is in the case of the momentary five [Rupa (from), vedana (feeling), vijnana (momentary consciousness), sanjna (notion), samskara (mental impressions) these have only momentary existence. In their case there can be no distinction between action and agent, simply due to the fact of their being momentary.] forms of mundane consciousness propounded by the Buddhists? In either case there can be no complete renunciation of action.
Then there is also a third standpoint (as held by the Vaisesikas): When a thing acts it is active, and inactive when that very thing does not act. If this be the case here, it is possible to entirely give up actions. But the specialty of the third point of view is that a thing is not ever-changing, nor is action itself the agent. What then? A non-existent action originates in an existing thing, and an existing action gets destroyed. The thing-in-itself continues to exist along with its power (to act), and that itself is the agent. This is what the followers of Kanada say. [Their view is that agent ship consists in 'possessing the power to act', not in being the substratum of action.] What is wrong with this point of view.
Vedantin: The defect indeed lies in this that, this view is not in accordance with the Lord's view.
Objection: How is this known?
Vedantin: Since the Lord as said, 'Of the unreal there is no being৷৷.,' etc. (2.16). The view of the followers of Kanada is, indeed, this that the non-existent becomes existent, and the existent becomes non existent.