“Know both Prakṛti and Puruṣa to be beginningless; and know the modifications and the guṇas to be born of Prakṛti.” Then the division of labour (13.20): “Prakṛti is said to be the cause in respect of agency in the instruments and effects (kārya-karaṇa-kartṛtve); Puruṣa is said to be the cause in respect of the experience of pleasure and pain.” This is the crux. All the doing — the body acting, the senses grasping, the mind willing — belongs to Prakṛti, the great task-master (recall 3.27, “the guṇas act; the Self does nothing”). The Puruṣa contributes only experiencing — and even that, as we shall see, only by a mistaken identification. Prakṛti supplies the whole machinery of action; the Self merely, and wrongly, thinks itself the doer.