So here prakṛtiṁ puruṣaṁ caiva. Although prakṛti is also Kṛṣṇa's nature, bhūmir āpo 'nalo vāyuḥ khaṁ mano buddhiḥ (BG 7.4). He said, apareyam: "This is inferior nature." So apareyam itas tu viddhi me prakṛtiṁ parām: "Another superior nature there is." What is that? Jīva-bhūtaḥ: "this living entity." So we are also prakṛti, and the material nature is also prakṛti. It is inferior prakṛti, and we are superior prakṛti. As we are now under the control of this inferior prakṛti, we can transfer ourself under the control of the superior prakṛti. That superior prakṛti is spiritual world. This material world means it is made of this inferior prakṛti, bhūmir āpo 'nalo vāyuḥ.
And there is another prakṛti, sanātana. That is stated in the Bhagavad-gītā. You'll find in the eighth chapter. Paras tasmāt tu bhāvaḥ anyaḥ (BG 8.20). Bhāva means nature. Avyakto 'vyaktāt sanātanaḥ. Sanātanaḥ means that is not destroyed. And this prakṛti is destroyed. Bhūtvā bhūtvā pralīyate (BG 8.19). So bhūtvā bhūtvā pralīyate means that prakṛti is fact, but the manifestation is temporary. It is not false.
Just like you become sometimes angry, so you show some symptoms. That symptom is within you, but it is manifested sometimes. Sometimes it is not manifested. But the propensity, the quality of your becoming angry, is there eternally. It is not that it is created. Anything... Sometimes you become passionate. To become passionate is there, it is not a new thing, but it sometimes appears, sometimes disappears.