Bhagavad Gita
18.18

ज्ञानं ज्ञेयं परिज्ञाता त्रिविधा कर्मचोदना | करणं कर्म कर्तेति त्रिविधः कर्मसंग्रहः ||

jñānaṁ jñeyaṁ parijñātā tri-vidhā karma-codanā karaṇaṁ karma karteti tri-vidhaḥ karma-saṁgrahaḥ

Translation

Knowledge, the object of knowledge, and the knower — these three are the triple impulse to action; the instrument, the action, and the agent — these three constitute the basis of action.

Interpretation

Action requires a triple foundation on the epistemological level (knowledge, object known, knower) and a triple basis on the practical level (instrument/karana, action itself/karma, agent/karta). This is pure Samkhya analysis applied to karma — showing that action is always a complex event involving multiple interdependent factors. No single element produces action alone; all three on both levels must be present. This analysis further dissolves the illusion of the simple, standalone ego-agent producing results by itself.