Listen now to the sacred teaching as revealed in the Kaṭha Upaniṣad, where the nature of the Self and ultimate reality is unfolded. There is an eternal aśvattha tree, whose roots stretch high above and whose branches spread downward. This wondrous tree is none other than the pure one, Brahman himself, the immortal. All the worlds rest upon him, and nothing exists beyond him—truly, he is that ultimate reality. All that exists here, the entire world, moves and lives because it is set forth by prāṇa, the vital force. He is a great and awe-inspiring presence, like a thunderbolt raised in majesty. Those who come to know this truth attain immortality. It is out of fear and reverence for him that fire burns, the sun shines, Indra and Vāyu fulfill their duties, and even Death, as a fifth, runs his appointed course. All cosmic order is governed by his presence. But if one fails to recognize him here, in this very life before the body falls away, then that soul becomes destined for further embodiment in the worlds of creation, unable yet to transcend. The vision of the Self varies according to the realm: as clearly as one sees an image in a polished mirror, so is he perceived in the self; as in a dream, so in the world of the ancestors; as in water, so in the world of the gandharvas; and as a shadow in sunlight, so in the world of Brahman. The wise one who understands how the senses are distinct, how they arise and set, and what their separate origins are—such a person is freed from sorrow. Beyond the senses lies the mind; beyond the mind is the higher intellect; beyond the intellect is the great self; and beyond even that is the unmanifest. Yet, beyond the unmanifest is the supreme Person, all-pervading and without attributes. Knowing him, the soul is liberated and attains immortality. His form cannot be seen by the eye, nor grasped by ordinary sight. He is apprehended only by the heart, by thought, by the mind. Those who know him in this way become immortal. When the five senses and the mind come to rest, and the intellect ceases its movement, that stillness is called the highest state. This steady holding of the senses is yoga. In that moment, one must be vigilant, for yoga is both the origin and the dissolution of all. He cannot be attained by speech, nor by the mind, nor by the eye. Only one who affirms “He is” with unwavering conviction can realize him. He is to be realized as truly existing, in both his manifest and unmanifest aspects. For one who recognizes his true existence, his essential nature becomes clear. When all desires that dwell in the heart are released, the mortal becomes immortal and attains Brahman here and now. When every knot in the heart is untied, the mortal becomes immortal—this is the essence of the teaching. Within the heart are a hundred and one arteries; among them, one rises directly to the crown of the head. By passing upward through this channel at the time of death, one attains immortality. The other arteries, spreading outward in all directions, lead to various paths of departure. The inner self, the person of the size of a thumb, is always seated in the hearts of all beings. With steadiness and care, draw him forth from your own body, just as one draws a reed from its sheath. Recognize him as pure, as immortal—know him as pure, as immortal. Having received this knowledge from Yama, the Lord of Death, and having mastered the entire path of yoga, Nachiketas became united with Brahman—free from all stain, free from death. So too can anyone who comes to know the self in this manner. Let us pray: May that supreme one protect us both together; may he nourish us both together; may we work together with great energy; may our study be vigorous and enlightening; and may we never bear ill will toward each other.