WHAT is the Supreme Spirit? By what relation to our experience shall we understand it? This is the subject of enquiry in this Upanishad. As the Isavasyopanishad is known by its first word, so also is this Upanishad named after its first word Kena, "By whom?"  Neither by the senses nor by human reasoning can we hope to comprehend the, nature of Brahman.

This is so because the subject, the object and the means are all identical. It is Brahman by which the understanding itself functions.  The Supreme Spirit is that by which the mind thinks; it is not one of the concepts that can be conceived by the mind, but it is that by which, indeed, one is able to think through his mind. It is that which enables the eye to see the ear to hear the breath to move.


These functions themselves depend on Brahman, and, therefore are these senses and the mind unable to comprehend the Brahman. Do not take this body that one has to feed and look after for the Soul.
Life is not the aggregate of the functions of the body but a function of the Highest Spirit, inasmuch as not a thought or a breath or a glance is possible without the Supreme Agent.

1-5, 6, 7,8

He who thinks that he knows really there by proves himself ignorant. He who realizes that he cannot know Him has best understood him. Those who seek to know Him, as they can grasp things of ordinary knowledge, can never achieve their object. Those who realize the limitation of the human mind in respect of the knowledge of the Supreme Spirit and, therefore, frankly confess ignorance, really approach a true understanding of it.


The limitation of human knowledge, when trying to comprehend the Supreme Being is brought out in the above epigram.

Not by reasoning but only by an awakening can we get a vision of the Supreme Spirit. Life, in relation to the Ultimate Reality, is like a state of sleep. Reason, in respect of Ultimate Reality, is like the impossible conception of a sleeping man trying to know what he is about, without waking up. As sleep is to waking, so is ordinary life to the state of realization.

Self-discipline gives strength of spirit: To one so strengthened, knowledge gives immortality:

The Self is itself immortal, and one has but to know it to become immortal.


A man dreams that he is suffering from a mortal illness and is dying. He suffers pain and even death. But the moment he wakes up, he is cured and regains life. So does Jnana give immortality to man. The third chapter of this Upanishad is an allegory to illustrate that everything rests on the Supreme Spirit. It is that which gives heat to Fire, and energy to Motion, and the power of knowing to individual knowledge, however great.

All beings are like electric lamps that glow by the power that is received by them from the Supreme Being, them selves not knowing it.  The gods were once elated at a great victory, and the Brahman appeared before them. They could not recognize or understand the vision. Agni, Vayu and Indra were sent to approach and understand Him.


They went, one by one, and tried to impress on the strange vision their respective Powers. But when they were challenged to prove their vaunted strength, Agni could not bum, and Vayu could not move by a hair’s breadth a dry bit of grass, which was placed, before them and which they attacked with all their strength one after the other. Indra went near to see, when the other two failed, but with his thousand eyes he failed to see anything whatsoever. The apparition disappeared altogether from his sight.

The said to Agni: "Oh, Jataveda, go and ascertain who this is, this adorable Being." He said: "Yes."


He ran up to the Being, who asked him: Who are you?" Agni answered: "I am Agni, I am also called Jataveda."


"And what is your strength?", the Being asked. "I can bum up all that is here on, earth," answered Agni.


He placed before Agni a bit of dry grass, saying, ‘Burn this." Going at it with all his energy Agni found that he could not bum it. He returned to the gods and said he could not make out who this strange Being was.


Then they said to Vayu: "Oh, do go ascertain who this is." Amid Vayu said: "So be it,"


He ran up to the Being, who asked him: "Who are you?" "I am Vayu, otherwise called Matarisva," answered Vayu.


Then said the Being: "What is your strength?" "Oh, I can sweep away whatever exists on this earth," answered Vayu.


Then the Being placed a withered blade of grass before Vayu, and said: "Move this." Vayu set on it with all his might, but could not move it; and he returned to the gods and said: "I could not make out who this is."


Thereupon, they beseeched Indra to find out who it was. He agreed to do so, but when he ran up, he found that the Being had gone out of his view altogether.


NOTE: I have interpreted as above on the lines of Sri Ramanujacharya's Commentary on the first six chapters of the Gita.