So Kṛṣṇa is chastising Arjuna because he has accepted, he's becoming His disciple, so the spiritual master has the right to chastise the disciple for right direction like the teacher, like the father. Similarly, although Kṛṣṇa and Arjuna are friends, but Arjuna has accepted Him as spiritual master. There should not be any compromising words as it is done between friend and friend. The right things must be said that "You are wrong. Don't talk nonsense. Talking like very learned man but you do not know anything." "Why I do not know?" "Because this body, while living, agatāsūn..." Asun means the living force. While the living force is there, and when the living force is gone, two conditions... This body is moving very nicely because the living force is there. And as soon as the living force is gone out, this nice body will no longer move. It will decompose. "Dust thou art, dust thou beist." "Again become..." It is called pañca-bhūta. Mix with the earth. Earth, water, fire, air, sky—these five gross elements are the ingredients of this body. 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. At least we can see five thousand years ago. The kṣatriyas were fighting severely one another, but still they are not in bodily concept of life.