Listen, dear one, to the secret teaching that Nachiketas received from Death himself, the wisdom that leads beyond sorrow and mortality. This truth is not grasped by the senses, nor by outward differences; it is attained only by the mind in its purest essence. Where one perceives diversity, thinking, “This is different from that,” there the soul wanders from death to death, caught in the cycle of birth and passing. But within each being, there dwells a presence, subtle as the flame of a lamp, no larger than a thumb, shining in the very heart of the self. This is the Lord, the knower of what was and what will be, unafraid and unshaken by anything. This, indeed, is the ultimate reality. This thumb-sized Person, luminous like a smokeless flame, is the eternal Lord—he is yesterday, he is today, and he is tomorrow. He alone is that which truly is. Yet, as water poured upon a rugged mountain rushes down in many streams, so too do people, seeing duties and paths as separate, follow them in many directions, divided by differences. But when pure water is poured into pure water, it becomes one and the same; so, O Gautama, when a knower realizes the self, he becomes one with that purity. In the city of eleven gates—the body—dwells the unborn Self, established in the crooked mind. Once he realizes his true nature, he grieves no more; he is liberated and free. This is that Supreme One. He is the swan who abides in purity, the Vasu who dwells in the mid-region, the priest on the altar, the guest in the house, present among men, among the noble, in the righteous, in the sky, born of water, born of cows, born of truth, born of mountains—he is truth itself, the great. He who dwells within raises the breath upward and sends the downward breath back; all the gods revere this subtle being, the dwarf seated in the center. When the embodied one is released as the body falls away, what remains? That alone is the immortal Self. No mortal lives by breath or by the downward breath alone; they live by another, upon whom both depend. Now, Nachiketas, hear of this ancient, secret Brahman, and how the self becomes, upon reaching death. Some embodied beings enter a womb to take on new bodies; others become stationary forms, shaped by their deeds and knowledge. He who, creating desire after desire, remains awake while others sleep—he alone is the pure one, Brahman, the immortal. All worlds rest upon him; none goes beyond him. This, indeed, is that Supreme One. As fire, though one, takes on many forms when it enters the world, so too the inner Self of all beings, though one, assumes the forms of every creature, both within and without. As wind, though one, takes on the shape of every object it enters, so too the inner Self of all beings, though one, becomes the form of every being, both within and without. As the sun, the eye of the world, is not tainted by the faults it perceives, so too the inner Self, though present in all beings, is untouched by the sorrows of the world, transcending them. He is the one ruler, the inner Self of all beings, who makes the one appear as many. Those wise ones who perceive him established within themselves attain eternal happiness; for others, there is no such joy. He is the eternal among the transient, the conscious among the conscious, the one who fulfills the desires of the many. The wise who behold him established within themselves find eternal peace; for others, there is no peace. They speak of that as the supreme bliss, indescribable. How may one know it? Does it shine, or does it not shine? There, the sun does not shine, nor the moon and stars; lightning does not illumine it, nor fire. By its light alone all else shines; when it shines, everything shines after it. This eternal aśvattha tree, with roots above and branches below, is that Supreme One—pure, Brahman, immortal. All worlds rest upon him; none goes beyond him. This is that. Whatever exists in this world moves by the power of prāṇa, the vital force. This is a great wonder, awe-inspiring like a raised thunderbolt. Those who know this become immortal. From fear of him, fire burns; from fear, the sun shines; from fear, Indra, Vāyu, and Death as the fifth, run their appointed courses. If one does not recognize him here, before the body falls, one becomes fit for further embodiment in the worlds of creation. As one sees his face in a mirror, so is the Self seen within; as in a dream, so in the world of ancestors; as in water, so in the world of gandharvas; as in shadow and sunlight, so in the world of Brahman. He who knows the distinctness of the senses, their rising and setting, and their separate origin, such a wise one does not grieve. Beyond the senses is the mind; beyond the mind is the higher intellect; beyond the intellect is the great Self; beyond the great is the unmanifest. Beyond the unmanifest is the Person, all-pervading and without attributes. Knowing him, a living being is freed and attains immortality. His form is not seen by the eye; none can behold him with sight. He is grasped by the heart, by thought, by the mind. Those who know this become immortal. When the five senses, together with the mind, come to rest, and the intellect stirs not, that is called the highest state. This firm holding of the senses is called yoga. At that time, one becomes vigilant, for yoga is the origin and dissolution of all. He cannot be attained by speech, nor by mind, nor by the eye. How else can he be realized, except by one who affirms, “He is”? He is to be realized as truly existing, in both his manifest and unmanifest aspects. For the one who knows him as existing, his true nature becomes clear. When all desires that dwell in the heart are released, then the mortal becomes immortal and here attains Brahman. When all the knots of the heart are untied here, then the mortal becomes immortal—this alone is the teaching. There are a hundred and one arteries of the heart; one of them rises to the crown of the head. Going upward through it, one attains immortality; the others, spreading in all directions, lead to different paths. The inner Self, no larger than a thumb, resides always in the hearts of all beings. With steadiness, draw him out from your own body, as one draws a reed from its stalk. Know him as pure, as immortal—know him as pure, as immortal. Having received this wisdom, taught by Death himself, and the entire discipline of yoga, Nachiketas became united with Brahman, free from stain, free from death. So too may any who know the Self in this way. May he protect us both together; may he nourish us both together; may we work together with great energy; may our study be full of light; may we never hate one another.