Kṛṣṇa concludes this section on the soul by calling it invisible, inconceivable, and immutable. It is invisible to material eyes and inconceivable to the limited material brain. We cannot detect the soul with instruments because it is spiritual, not physical. Therefore, knowledge of the soul must be accepted from the authority of the scriptures rather than from experimental observation. Kṛṣṇa says, “Knowing the soul to be such, you should not grieve.” If the soul is beyond the range of physical destruction and mental perception, then material grief is logically misplaced. Arjuna’s sorrow is based on what he can see—the bodies of his kinsmen. Kṛṣṇa’s instruction is based on what is true but invisible—the eternal nature of the self. He asks Arjuna to upgrade his vision from the sensory to the transcendental.