So as soon as the soul is out of this body, this body again... Conservation of the energy. The earthly energy goes to the earth, the waterly energy goes to the water. It is a combination of earth. water, air, fire. So they become decomposed. And become distributed to different elements. And that is the scientific law, it is called conservation of energy. The energy is never lost. It comes back again to the original stock.
So Kṛṣṇa says this body, either in living force or without living force... Without living force it is called dead. With living force it is called living. In both the condition, a learned man..., learned man means one who knows brahma-bhūtaḥ. One who knows Brahman, one who has realized Brahman. Brahma-bhūtaḥ prasannātmā (BG 18.54). As soon as one is on the stage of brahma-bhūtaḥ stage, he can understand that "I am not this body. I am separate from this body." This knowledge was very common knowledge.