The exponents of the Upaniṣhad tell us that the First and the Second Chapters lay down the thesis of the whole Upaniṣhad. They declare the essential content of the whole scripture, while the Third and the Fourth Chapters confirm this thesis by more elaborate discussions which happen to be in the context of an assembly held in the court of the King Janaka, where learned men and sages appeared to have conferred together for the purpose of mutual edification.

The sage Yājñavalkya is the leading figure in this great assembly of Janaka, and he is questioned by various sages. Eight of them are mentioned as principal ones, the first one being Aśvala, the chief priest of the sacrifices performed in the Yajñasala of Janaka, who queries Yājñavalkya as to the way in which death can be overcome by those who are really subject to death, namely the performers of actions, the means of action, as well as the goal of action. All these are perishable in the world of space and time; anything that you do has an end, just as you yourself will have an end one day or the other. If everything is to be destroyed, is there a way of escape from this destructibility of things, or is everything doomed to failure in the end, and all will be wiped out of existence? What is the escape? What is the remedy? What is the means? This was the question of Aśvala, and Yājñavalkya explained that the mortal becomes immortal the moment it returns to its cause. When the senses and the mind and the means of action and the performer himself - all get identified in their meditations with their deities from where they come and to which they actually belong and by which they are superintended; when the transcendent divinities which are the realities behind the various functions and organs of the individual are meditated upon as organically connected to oneself, then there is an internal relationship established between the individual and the universal. Then the mortal becomes immortal; otherwise every action is perishable and everything that an action brings as result, also, would be perishable. That was the point made out by Yājñavalkya in regard to the question of Aśvala, as to how the mortal can become immortal in spite of the fact that everything is subject to mortality in this world.

Then the next question was from Artabhāga about what the Upaniṣhad specifically calls Grahas and Atigrahas - how the senses are subjected to the influence of objects, so that there is finitude on the part of the subject, which is taken advantage of by every object, and which is also the cause of the attachment of the subject to the object. Every object of sense is an Atigraha, and every sense is a Graha. That which catches hold of an object is called a Graha, and that which intensifies the attachment of the subject is the Atigraha. So, like a crocodile catching hold of a person's legs in a river and not letting him off, the objects catch hold of the senses which are naturally prone to a movement towards the objects themselves.

Is there a way out of this predicament of subjection to utter suffering by way of dependence on objects which are not only perishable in their nature but also tantalising in their character?

Neither do they promise real satisfaction, nor are they in a position to give real satisfaction under any circumstance. So there is a phenomenal attachment of the subject to the object, on account of which there is a mutual destruction of both brought about by the power of death, which cannot be overcome as long as the senses and the mind, in their individual capacities, remain what they are and depend on the objects of sense which are in space and in time and are influenced by the objects, so that their attachments get intensified. The only solution, says Yājñavalkya, is the meditation on the Transcendent Being, which is beyond the realm of both the senses and their objects. Just as death consumes everything - there is nothing which cannot be subject to death in this world - there is something which can swallow death itself, and that has to be meditated upon - the Death of death - which is the Supreme Reality, Brahman.

Then, Bhujyu asks: What are the limits of the worlds? Where do the worlds end? Is there a limit or a consummation for this vast expanse called the universe?

Yājñavalkya says: There is no end. There are worlds within worlds and worlds beyond worlds, until we reach the cosmic border itself which hinges upon the existence of Hiraṇyagarbha; and the end of the worlds is the existence of the Supreme Being, Hiraṇyagarbha, the Final Existence, and there is no chance of having a knowledge of the limits of the worlds as long as we behold them as if they are outside us. The worlds are intertwined with us. We are a part of the worlds, and the only way of getting an insight into the vastness of the worlds, as they are, is an insight into one's own experience, which is inseparable from the worlds. Here do go, in the end, the performers of the true horse sacrifice.

The question, again, is put by Ushasta, as to how the internal Self can be experienced in its essentiality. Yājñavalkya replies that the internal Self cannot be experienced as objects are experienced. It is not an object, because it is the experiencer of things. It is that which sees things, that which understands things. The Understander cannot be understood, the Seer cannot be seen, the Hearer cannot be heard and the Experiencer cannot be experienced. So, the difficulty in the knowledge of Reality is that it is the Subject, par excellence, of every centre of experience. Therefore the question as to how the experiences, or the real Ātman, can be experienced is out of point. The Ātman cannot be experienced in the ordinary sense of the term, because it is the experiences himself. You cannot 'know' the Ātman as you 'know' things, is the answer of Yājñavalkya. The Ātman is Experience.

What happens when the experience comes? When the knowledge of the Ātman dawns, what is the consequence? This was another question posed before Yājñavalkya by Kahola. The answer is that when the knowledge of the Ātman arises, desire for things automatically subsides. Just as a person who has woken up from sleep is concerned not with all the gorgeous beauty that he saw in the world of dream and the magnificences which he possessed as his properties; there is an automatic rising above the various attractions of things, and likes and dislikes, which are common to the world of experience, spontaneously get transcended, because of the fact that the Ātman is the Self of all. It is the pull of the Ātman in the objects that is ultimately responsible for attraction towards objects. It is the Ātman that is mistaken for objects, and the objects are mistaken for the Ātman, in turn. When the Ātman is mistaken for objects, there is a transference of qualities taking place between the experiences and the experienced. It is the presence of the Selfhood of things which is responsible for the mutual connection of the seer and the seen, which fact is missed in the ordinary phenomenal perception of things. The intervention of space between the seer and the seen defeats the attempt on the part of any person to know the secret that is taking place in the process of perception. We are mistaken when we think that the object of experience is outside us. It is not outside because, if it were really outside, it would not have been possible to experience it. It is involved in the very process of knowledge, and as the process of knowledge is involved in oneself, the object, also, is involved in oneself only. So, it is the Universal's interference in things that is ultimately the cause of the experience of even the apparent duality of objects. This is the outcome of the answer of Yājñavalkya in the context of how the Ātman is realised and what follows as a consequence of the knowledge of the Ātman.

Then, Gārgi puts the question: What are the limits of things? Where is anything founded? Where is this world rooted and where are the other worlds fixed? Where is the last cause ultimately situated? What is the Cause of all causes?

Yājñavalkya says that the Cause of all things is Akshara, the Imperishable, the Absolute; and It is not rooted in anything, though everything and all the worlds are rooted in It. Under the law of the Absolute, everything moves, everything acts, and everything functions. Even the physical harmony, regularity and system that we observe in Nature is due to the existence of this Absolute. Its very being is the law of all things. It does not command things by word of mouth; it does not speak as we speak through speech. It exists! Its very existence is an influence exerted inexorably on everything. The symmetrical action and movement of things in every realm of experience, in every level of being, in every plane of existence, is due to the operation inwardly, subtly, of the law of the Absolute. It is due to it that the sun shines, it is due to it that rain falls, it is due to it that the earth revolves round the sun, it is due to it that we breathe, it is due to it that we exist, and think, and are happy. So, that is the ultimate Reality, and it is not founded upon anything else; everything is founded upon That, says Yājñavalkya. Anything that is done here without a knowledge of this Reality is a waste, concludes the sage.

Uddālaka asks: What is the Antāryamin, the Indweller? What does one mean by the Indweller, and where does He dwell; what does He indwell? Where is He?

The answer to this question, given by Yājñavalkya, is that the Antāryamin is the Ātman, and It cannot be known. While It knows everything, It is not known to anybody. The Antāryamin is the Indwelling Principle of all things. That which indwells an object, knows the nature of that object; but the object cannot know its Indweller at all, because the Indweller is the seeing Consciousness, the experiencing Reality. It cannot be externalised, It cannot be objectified, It cannot stand in the position of a known, and therefore Its existence is not known. No one can ever have even an inkling of Its existence, because the highest faculty of knowledge, which are our own mind and intellect, cannot reach even the fringe of this Reality. The mind and the intellect are thrust outwardly - they are extrovert; they are forced to move in respect of things external to them, and so they cannot know what is behind them. The mind, the senses and the intellect cannot know what is transcendent to their own existence. So, the propeller of even the mind and the intellect, the cause of the functions of even the senses, cannot be known by these faculties. This is the Indweller. This Indwelling Principle is not merely in me, or in you, but in everything - in physical, in astral and in causal beings. It is in every level of experience. It is outside, It is inside and It is universal, and, therefore, neither the objects outside can know It, nor the intellect and mind can know It, nor even the divinities which are apparently the superintending principles over the senses can know It. No one can know where It is, and yet without Its existence nothing can be. Its existence is the existence of everything. Such is what is called the Antāryamin. You cannot know It, you cannot see It; you cannot hear It, you cannot think It, you cannot understand It; because this Being is the Seer, the Hearer, the Thinker, the Understander, the Experiencer of all; It is the Sarvanubhuh - the Being of everything.

The last questioner was Śākalya who raised various types of queries, some of them being: how many gods are there; what are the presiding deities of the various quarters, and objects, etc., to which all a proper answer was given by Yājñavalkya.

Yājñavalkya mentions that there is a divine principle present in every little bit of things in this world. There is nothing undivine anywhere - in all the physical objects, in anything that we regard as phenomenal, external, anything that is apparently perishable, destructible, mortal, earthly - in all these things there is the hidden divine Reality. On account of the presence of this divinity, a thing appears to be there. Even appearance could not be, if Reality were not to be there. The presence of Reality in anything comes into relief not merely when an object is visualised, but when it is viewed in its organic connectedness with its perceiver as well as the deity transcending both.

Thus, all the questions put by the eight sages in the court of King Janaka were answered by Yājñavalkya, and finally he himself sums up his discourse by saying that the origin of the human being himself is Brahman. Everything comes from this Divinity. The individual existence of anything is not brought about by the mixture of elements, as the scientists would tell us. It is not a chemical combination that is the cause of the physical body or of the mental functions, because they are all inert things. That which is inert or unconscious cannot produce consciousness. Wherefrom does consciousness in human beings come? It cannot be due to a conglomeration or a mix-up of physical elements, because that which is not in the cause cannot be in the effect. When the cause is only hydrogen and oxygen, and such other chemical substances, which are inert in nature, how can consciousness come out of them? The consciousness which is the effect, apparently, seen in the individual, has to be traced back to a Universal Consciousness. Vijñānam anandam brahma rātirdātuh parāyanam: Consciousness - Bliss is Brahman, the Goal of all aspirations. This is what Yājñavalkya concluded, in answer to all the queries posed before him. There is one Reality behind everything, which appears as the manifold things in this world. Here is concluded the Third Chapter.