The word upanishad means “sit down near”: upa (near), ni (down) and shad (sit). Traditionally, the student sat down near the teacher to receive secret instruction, and in this way knowledge was passed down from teacher to student, linking each new generation back to the ancient tradition of the Upanishads. Many of the Upanishads consist of a dialogue between teacher and student in the deep quietude of a forest hermitage (āshrama) or in the home of the teacher (where the students lived as part of a system called guru-kula).
The great teacher Shankara explained the word upanishad as “the knowledge of Brahman by which ignorance is destroyed.” In other accounts, “sit down near” (upanishad) refers to the hidden connection between everything, whether it is the connection between the teacher and student, or more broadly, the infinite correlation among all things, the oneness of reality. In this way the word upanishad might be thought of as a state of consciousness in which everything is connected to one’s own Self. According to India’s ancient tradition of knowledge, the Upanishads were cognized by rishis, or seers. The profound truths dawned spontaneously in the silent depths of their consciousness and were recorded by them and passed down through generations, first orally and later in written form. According to the Muktikā Upanishad there are 108 Upanishads, although scholars later recorded more than two hundred.
The first ten are considered to be the principal Upanishads:
Īsha, (Shukla Yajur Veda)
Kena, (Sāma Veda)
Katha, (Krishna Yajur Veda)
Prashna, (Atharva Veda)
Mundaka, (Atharva Veda)
Māndūkya, (Atharva Veda)
Taittirīya, (Krishna Yajur Veda)
Aitareya, (Rig Veda)
Sometimes the Shvetāshvatara is also added, bringing the list to eleven. (Krishna Yajur Veda)
Shankara commented on these eleven. Because he also referred to four other Upanishads (Kaushītakī, Jābāla, Mahānārāyana and Paingala) in his commentary on the Brahma Sūtras, these Upanishads are sometimes also included as principal Upanishads, bringing the list to fifteen (or fourteen, if the Shvetāshvatara Upanishad is not included).
Each of the Upanishads is associated with one of the four Vedas: Rig, Sāma, Yajus and Atharva. For the nine Upanishads in this volume, the Aitareya belongs to the Rig Veda; the Kena belongs to the Sāma Veda; the Katha, Taittirīya and Shvetāshvatara belong to the Krishna Yajur Veda (the Yajur Veda has two branches); the Īsha belongs to the Shukla Yajur Veda; and the Prashna, Mundaka and Māndūkya belong to the Atharva Veda.
Upanishads of the same Veda often have the same introductory and concluding verse (shānti-pātha). Some of the Upanishads are in verse, others are in prose and a few are a mixture of both. While several Upanishads are short, such as the Māndūkya (twelve verses) and the Īsha (eighteen verses), other Upanishads are considerably longer, such as the Brihadāranyaka and Chāndogya Upanishads. Slight variations in wording are found, as they have been passed down in an oral tradition for thousands of years.
The Upanishads are the last part or culmination of the Veda and so are called Vedānta. They are known as the gyāna kānda, the section of the Veda that deals with knowledge— knowledge of the ultimate reality. Since the Upanishads are part of the Veda, they are regarded as shruti, or “that which is heard.” Traditionally, they are considered to be apaurusheya, which means they are not the creation of individuals, not made up like poetry; rather they were revealed to enlightened seers who saw and heard these truths in the depths of their awakened consciousness. The Upanishads are also thought to be nitya— true for all time, all places and all people.
INFLUENCE OF THE UPANISHADS
The Upanishads have enjoyed a growing global influence over the centuries. The first known translation of the Upanishads, from the original Sanskrit into Persian, was commissioned in 1656 by Muhammad Dara Shikoh, the eldest son of Shah Jehan, who built the Taj Mahal. In 1802, the French scholar Abraham Anquetil-Duperron translated the Persian volume into French and Latin.
The German philosopher Arthur Schopenhauer read Anquetil-Duperron’s Latin translation and famously said of the Upanishads:
lation and famously said of the Upanishads:
The Upanishads are the production of the highest human wisdom and I consider them almost superhuman in conception. The study of the Upanishads has been a source of great inspiration and means of comfort to my soul. From every sentence of the Upanishads deep, original and sublime thoughts arise, and the whole is pervaded by a high and holy and earnest spirit. In the whole world there is no study so beneficial and so elevating as that of the Upanishads. The Upanishads have been the solace of my life and will be the solace of my death.
Influenced by Schopenhauer, the German scholar Paul Deussen translated the Upanishads and said, “On the tree of wisdom there is no fairer flower than the Upanishads and no finer fruit than the Vedānta philosophy.”
In America, Henry David Thoreau, Ralph Waldo Emerson and Walt Whitmanwere among the first to read the literature of India. Thoreau described the universal nature of the Vedas and eloquently gave an account of reading them:
What extracts from the Vedas I have read fall on me like the light of a higher and purer luminary, which describes a loftier course through a purer stratum,— free from particulars, simple, universal. It rises on me like the full moon after the stars have come out, wading through some far summer stratum of the sky. . . . One wise sentence is worth the state of Massachusetts many times over.
Emerson noted, also eloquently, how the ancient literature of India resolves many of the questions of existence that the modern mind is engaged in solving:
It was as if an empire spoke to us, nothing small or unworthy, but large, serene, consistent, the voice of an old intelligence, which in another age and climate had pondered and thus disposed of the questions that exercise us.
Walt Whitman read the Upanishads and described the universal spirit of this knowledge:
These are the thoughts of all men in all ages and lands, they are not original with me, If they are not yours as much as mine they are nothing or next to nothing, If they do not enclose everything they are next to nothing, If they are not the riddle and the untying of the riddle they are nothing, If they are not just as close as they are distant they are nothing.
The Austrian physicist Erwin Schrödinger discussed the universal nature of knowledge and the universal nature of consciousness found in the Upanishads:There is no kind of framework within which we can find consciousness in the plural; this is simply something we construct because of the temporal plurality of individuals, but it is a false construction. . . . The only solution to this conflict insofar as any is available to us at all lies in the ancient wisdom of the Upanishad.
Schrödinger’s contemporary, the Danish physicist Niels Bohr, said, “I go into the Upanishads to ask questions.” Referring to the Upanishads as “some of the most sacred words that have ever issued from the human mind,” Rabindranath Tagore wrote, “The messages contained in these, like some eternal source of light, still illumine and vitalize the religious mind of India. . . . Seekers of life’s fulfillment may make living use of the texts, but can never exhaust them of their freshness of meaning.”
One of the most influential persons to introduce the Upanishads to a wider Western audience was the Oxford scholar and second president of India, Sarvepalli Radhakrishnan. In 1953, while vice president of India, he published his translation of the Upanishads. Here he identifies their central theme: Anyone who reads the Upanishads in the original Sanskrit will be caught up and carried away by the elevation, the poetry, the compelling fascination of the many utterances through which they lay bare the secret and sacred relations of the human soul and the ultimate reality.
The Upanishads are a celebration of the awakening of the Self (Ātman), a state of unbounded pure being, pure bliss. They reveal the great truth of life: The Self of the individual is identical to the Self of the universe (Brahman). They sing out, “I am totality” (aham brahmāsmi). The wholeness of life, Brahman, expresses itself as every particle of creation and as every human being. This is the profound message of the Upanishads.
The Self, Unbounded Awareness As we have seen, the Upanishads define Ātman as the Self, the inner essence that transcends the personality. The Self is awareness itself, devoid of any content such as thoughts, feelings and perceptions. It is pure wakefulness, the awareness that enables one to be conscious. Like the silent depth of the ocean, the Self is described as the abstract core of the mental and physical levels of reality. It is not limited by any kind of physicality; it is pure spirituality, with no distinctions, no boundaries, no thoughts, no emotions, no sensations— just pure, unbounded awareness aware of itself. While the Upanishads describe the Self as non localized, they refer to the space within the heart as “the seat of consciousness,” the place where consciousness is most vibrant, often referred to as a secret cave. For example, the Katha Upanishad says, “The inner Self is ever seated deep in the hearts of men,” and the Mundaka Upanishad describes the Self as set in the heart:
Vast, divine, of inconceivable form, subtler than the subtle, that shines forth, farther than the farthest, and yet here, near at hand. It is here within those who see, set in the secret place of the heart. Not by the eye is it grasped, nor even by speech, nor by the other senses, nor by austerity or action. When one’s nature is purified by the clarity of knowledge, only then, as he meditates, does he perceive him, the indivisible.
In these verses, after first locating the Self in the region of the heart, the Upanishad discusses how the Self is known. The Self is not known through sight, because it has no form. Neither is the Self known through hearing, because it has no sound. The Self is known when the mind has completely settled and there are no perceptions of anything limited or temporal in nature. What remains is awareness itself in its unbounded state. One is still aware, but there is no localized object of awareness. Awareness is aware of itself alone, as described in the Brihadāranyaka Upanishad:There he does not see. Though seeing, he does not see. The seer does not cease seeing, because he is indestructible. But there is no second, nothing other than himself that he could see. There he does not speak. Though speaking, he does not speak. The speaker does not cease speaking, because he is indestructible. But there is no second, nothing other than himself to whom he could speak. There he does not hear. Though hearing, he does not hear. The hearer does not cease hearing, because he is indestructible. But there is no second, nothing other than himself that he could hear. There he does not think. Though thinking, he does not think. The thinker does not cease thinking, because he is indestructible. But there is no second, nothing other than himself about which he could think. There he does not know. Though knowing, he does not know. The knower does not cease knowing, because he is indestructible. But there is no second, nothing other than himself that he could know.
Each of these verses describes awareness, but not awareness of anything in particular. There are no thoughts, no sounds, nothing to see, and yet one is awake. All objective experience has disappeared and only pure subjectivity remains. This is the experience of the Self, often described as “pure being.” The Kena Upanishad refers to the Self as the “the ear of the ear, the mind of the mind, the speech of speech, the breath of the breath, the eye of the eye.” Pure consciousness is the knower, and all other values are the means through which it knows the subtle and gross aspects of manifest life. Ātman is not only a theoretical concept, but a universal reality that the Upanishads advise the seeker to realize. In the Brihadāranyaka Upanishad, the famous teacher Yāgyavalkya, before departing to the forest, says in his last words to his wife Maitreyī, “That Ātmā alone is worthy of seeing, hearing, contemplating and realizing.” This message from Yāgyavalkya is the heart of the Upanishads.
The Brahma Sūtras, which are a clarification of the Upanishads, refer to this passage (vishaya vākya) in the first section (adhikarana), indicating that the experience of the Self, unbounded pure consciousness, is the central teaching of the Upanishads.
Brahman, the Totality
If Ātman is like a wave in the ocean, the whole ocean is Brahman. The Mundaka Upanishad describes the universal nature of Brahman: Brahman, truly, is this immortal. Brahman is in front, Brahman is behind, it is to the right and to the left, it extends below and above. This whole world is nothing but Brahman, the supreme.
From the standpoint of the highest state of consciousness, everything is Brahman, which is why it is translated as “totality” or “wholeness.” For example, the Chāndogya Upanishad says, “All this is totality” (sarvam khalvidam brahma), meaning that Brahman exists within all things: Brahman is the ultimate content out of which everything and everyone in the cosmos is made. The Māndūkya Upanishad says, “Truly, all this is Brahman” (sarvam hyetad brahma). A passage in the Īsha Upanishad describes Brahman:It is one, unmoving, swifter than the mind. The senses cannot reach it. It darts ahead. Standing still, it outruns those who run. Within it the breath of life supports all that stirs. It moves and it moves not. It is far away and it is close by. It is within all this. It is outside all this.
Brahman is within all things and also transcends all things. Brahman is in this world and beyond this world. Brahman is unmanifest and manifest, unity and diversity, silence and dynamism. It is the eternally self-aware wholeness that is more than the sum of its own innumerable aspects. According to the Upanishads, the realization of Brahman (brahma vidyā) is the purpose of life. Like a compass that is always turned toward the north, the mind is always directed toward Brahman because Brahman is a state of happiness: “Brahman is that toward which the mind moves, as it were, that by which it is ever aware and that which forms its purpose.”
The Self Is Brahman
Because Brahman permeates every aspect of creation, it also permeates each of us. In other words, Brahman is our own being, our own pure consciousness. In this sense, Brahman is the same as Ātman. Brahman is the ocean and Ātman is a drop in the ocean. Each drop of water can say, “I am the ocean,” because each drop is made of the same substance of which the ocean is made. The fully realized not only perceive the drop merging into the ocean but, as the Indian mystic poet Kabir writes, perceive the ocean merging into the drop. The identity of Ātman with Brahman is the main principle of the Upanishads, expressed in the saying “Thou art that” (tat tvam asi). This is one of four great expressions, called mahāvākyas, that were emphasized by Shankara in his commentaries on the Upanishads. In addition to “Thou art that,” these expressions are: “I am totality” (aham brahmāsmi), “This Self is Brahman” (ayam ātmā brahma) and “Consciousness is Brahman” (pragyānam brahma).
These celebrated expressions convey one common meaning: Brahman, which pervades everything, can be known within each individual. The full meaning of each mahāvākya is gained through direct experience: One can access the whole of creation just by accessing one’s own Self. The identification of Ātman with Brahman is found throughout the Upanishads. For example, the Taittirīya Upanishad states, “He who is here in the person and he who is there in the sun— he is one.” A passage from the Īsha Upanishad says, “He who is that person afar, I am he.” (The words he and person in the above quotes do not refer to Brahman as a limited individual entity, but as unbounded being.) The Kena Upanishad explains how one may have a tendency to venerate Brahman as far off, or as being limited to only this or that particular form, whereas Brahman is wholeness, a wholeness which includes the person who is doing the venerating: That which is not uttered by speech, but by which speech is spoken— that alone know to be Brahman, not what people venerate here. That which is not thought by the mind, but by which, they say, thought is thought— that alone know to be Brahman, not what people venerate here. That which one does not see with the eye, but by which the eye sees— that alone know to be Brahman, not what people venerate here. That which is not heard by the ear, but by which hearing is heard— that alone know to be Brahman, not what people venerate here. That which is not breathed by breath, but by which breath is breathed— that alone know to be Brahman, not what people venerate here.
In the above verses, we see that the essential nature of Brahman is the transcendental reality that animates the senses, as well as the senses themselves. The identification of the Self with Brahman is the great principle upon which the Upanishads stand. In other words, any individual point of creation, no matter how minuscule, contains the whole of creation, like a set of pearls in which each pearl contains the entire strand. In a similar way, the DNA of each cell contains the information for the entire physiology. The universe of the Upanishads is holographic: Each point of infinity is yet infinity, and infinity is made up of innumerable points. Brahman expresses itself as every aspect of creation, while ever remaining the limitless essence of all its manifestations. A passage from the the Mundaka Upanishad illustrates how Brahman serves as the ultimate content from which all life is woven:
His head is fire, his eyes are the moon and the sun, his ears are the regions of space, his speech is the Vedas unfolded, his breath is the wind, his heart is the universe, and from his feet comes the earth. Truly, he is the inner Self of all beings. He on whom are woven sky, earth and the space between, also mind, along with all the vital organs— know him alone as the one Self.
Fulfillment of Desire
Desire provides a direction for consciousness to become materialized, and therefore life-supporting desires are the means through which life flows. Denial of desire through withdrawal is not the ideal found in the Upanishads, which portray the fulfillment of desire as a natural consequence of knowing the Self. For example, the Kena Upanishad points out that “Through the Self one gains strength” (ātmanā vindate vīryam). The Sanskrit word for strength is vīryam, which also means “vitality” or “energy.” In addition, the Taittirīya Upanishaddescribes the material benefits for one who knows the Self and has realized Brahman:
Whatever world a man of purified nature sees clearly in his mind, and whatever desires he desires, that world and those desires he wins. He who knows Brahman dwelling in the secret place, in the field of the transcendent, wins all desires together with Brahman, the all-knowing.
The Katha Upanishad expresses the same idea:
This imperishable indeed is Brahman. This imperishable indeed is the supreme. For one who truly knows this imperishable, whatever he desires is his.
Transcending the Intellect
In the Upanishads, the Self is more than an intellectual concept— it is a living experience. For example, the Katha Upanishad declares, “This Self cannot be attained by instruction, nor by the intellect, nor yet by much learning.” The Brihadāranyaka Upanishad says, “Let him not ponder over words, for many words are weariness.” Since the Self transcends logic, the Katha Upanishad states that the Self must be learned from someone who knows it by direct experience:
Taught by an inferior man, this Self cannot be easily known, even though often reflected upon. Unless taught by one who knows him as none other than his own Self, there is no way to him, for he is subtler than subtle, beyond the range of reasoning.
Here the Upanishad explains that the Self is known through direct experience of pure consciousness, not through mere learning. The Self is known on the level of pure being, which goes beyond the intellect: “When known through an awakening, it is rightly known.” The Upanishads are critical of knowledge not obtained through scholarly study alone:
Living in the midst of ignorance, wise in their own eyes, thinking themselves scholars, fools go round and round, running here and there, like the blind led by the blind.
The Katha Upanishad points to the danger of trying to know the Self through the intellect alone: “Not by logic can this realization be won.” Logic involves fragmentation, a feature of the intellect, which discriminates. However, with the experience of universal being, a continuum of existence dominates awareness, and fragmentation is seen in the larger context of wholeness. The Katha Upanishad emphasizes the danger of attempting to know the Self solely through intellectual knowledge:
He who has not discarded wrong action, who is not tranquil, who is not collected, whose mind is not at peace, cannot attain this Self through knowledge.
The Upanishads repeatedly state that reality is bliss, ānanda. Ānanda becomes enlivened by knowing the Self, because the essential nature of the Self is bliss, as this passage from the Taittirīya Upanishad states:
Surely by grasping the essence, one is filled with bliss. Who indeed would breathe, who would be alive if this bliss did not pervade space? For this essence alone bestows delight.
Bliss replaces anxiety. The Taittirīya Upanishad describes how a person rids himself from distressing thoughts as a result of experiencing bliss: “He does not torment himself, thinking, ‘Why have I not done what is right? Why have I done what is sinful?’ Knowing this [the bliss of Brahman], he frees himself from these thoughts.”
Numerous passages in the Upanishads state that fear and guilt vanish for one who has realized the Self. For example, the Chāndogya Upanishad says, “Knowing the Self, one overcomes sorrows and suffering,” and the Katha Upanishad says, “Having known the vast, all-pervading Self, the wise man does not grieve.” The Taittirīya Upanishad states, “One is freed from fear only when he finds that fearless ground— invisible, bodiless, unutterable, undefined.” The Mundaka Upanishad says that the realization of Brahman takes a person beyond sorrow: “He passes beyond sorrow. He passes beyond evil. Freed from the knots of the heart, he becomes immortal.” The Katha Upanishad describes freedom from fear as a by-product of the experience of the Self:
He who knows this enjoyer of delight— the Self, the living soul, always near, lord of what was and what will be— no longer hides in fear.
The Purpose of Life
The Upanishads state that the purpose of life is to realize Brahman, the wholeness of life first discovered in the Self and eventually perceived as the common constituent of every particle of creation. In the Chāndogya Upanishad, when the young Shvetaketu was returning home from his studies, his father asks him, “When you know one lump of clay, you know everything made out of clay. Do you know that, by knowing which, everything becomes known?” Shvetaketu then asks for instruction, and his father teaches him the unbounded nature of the Self and its identity with Brahman. Dr. Radhakrishnan points out that “Brahman is not merely a featureless Absolute. It is all this world.” Therefore, to realize Brahman is not life denying, but affirming the identity of oneself with the world. Then one can say, “I am everything,” or in the beautiful words of the Shvetāshvatara Upanishad:
You are woman. You are man. You are the youth and the maiden too. You are the old man hobbling along with a staff. Once born, you are the face turned in every direction. You are the dark blue butterfly, you are the green parrot with red eyes. You are the thundercloud, pregnant with lightning. You are the seasons, you are the seas. You are without beginning, present everywhere. You, from whom all worlds are born.
SHANKARA’S COMMENTARY ON THE UPANISHADS
Shankara examined the various trends of thought found in the Upanishads and taught a philosophy that came to be known as nondualistic Vedānta. His understanding of the literature still shapes the central teaching of the Veda in India. Shankara based his teaching on a threefold textual foundation, called the prasthāna traya:
Brahma Sūtras and
Shankara wrote commentaries on each of these, and therefore he is known as a teacher (āchārya) and is referred to as “Shankarāchārya.” Shankara begins his commentary on the Upanishads by writing, “The sole purpose of all the Upanishads is to determine the nature of Ātman.” He describes Ātman as eternal, unchanging, undifferentiated, omnipresent and constant, because it cannot be created (utpādya), it cannot be transformed (samskārya), it cannot be grasped like an object, and it cannot be damaged or destroyed.
Probably the most well-known teaching of Shankara is the principle of illusion, or maya as "that which is not." According to shankara, maya is rooted in ignorance (avidya), which is to say that maya is due to ignorance of the state of unified awareness. According to Shankara, ignorance is caused by superimposition, which he defines as an apparent presentation to consciousness by way of remembrance of something previously perceived somewhere else.
In short, he defines maya as the condition of perception dominated by memory. For example, someone may be filled with fear not because of a present threat, but because of a remembered threat. In other words, a person fails to see the distinction between the threat of an actual tiger and the memory of a tiger. Both are experienced as a real threat. Modern neurophysiologists might associate this with a hyperactive amygdala, which locks a person in the fight-or-flight response. For Shankara, this condition affects everyone to some degree, except those who have gained liberation (moksha). Shankara teaches that memory covers the perception of infinity, which is right in front of us. This covering is maya, illusion.
Perhaps one might add, "What if there is a clear danger, such as fatal sickness?" Shankara's answer would be that the essential nature of the Self is unbounded consciousness, which can never be endangered because it is an immortal reality. The suffering that one perceives is due to the lack of perception of one's essential nature. For Shankara, all illusion is rooted in ignorance of the true reality, which is Brahman. The Illusion of ignorance can be changed when an individual's reality is changed, like the darkness that is removed when the light is brought in.
Superimposition is the situation where the reality of Brahman is covered up by afalse, inaccurate perception of reality. Shankara taught that superimposition is only an appearance, like a string that appears to be a snake. In reality, there is only a string; in reality, there is only Brahman.
According to Vedanta, Brahman is without qualities, although it has three essential characteristics: existence, consciousness and bliss. These qualities are not considered descriptions of Brahman, but the essential nature of Brahman. While brahman is said to be indescribable, Shankara highlights many words from the Upanishads to describe it: one, full, all-encompassing, all-pervading, vast, omnipresent, supreme, without end, without beginning, eternal, undivided, self-existent, self-luminous, imperishable, unchangeable, indestructible, inconceivable, unshakeable, immovable, and constant.
The Isha Upanishad states that Brahman "is far, yet is within". The Chandogya Upanishad states that brahman is "one reality without a second". This last passage indicates why Shankara calls advaita or non dual.
Shankara states that the world by itself cannot be real because it is impermanent. Howver, since the world can be perceived, it cannot be unreal either. It cannot be completely nonexistent because we have an experience of it. Shankara states in his commentary on the Brahman Sutras, "It can never be what is actually perceived as non-existent. Therefore, he declares that the world is neither real nor unreal. Our experience of the world, according to Shankara, has been superimposed upon Brahman, which is the true reality. The false perception of the world as separate from Brahman is ignorance. As the Shvetashvatara Upanishad beartifully expresses, ignorance is not the perception of diversity itself, but the perception of diversity separated from oneself:
In the vast wheel of Brahman in which all things live and rest, the swan, the self, flutters about, thinking himself and the mover to be separate.
The consequence of perceiving diversity without unified awareness is becoming bound to the cycle of birth and rebirth, as described in the Katha Upanishad: "He goes from death to death who sees even a hint of difference here." Shankara states that when Brahman is permanently experienced by the individual, there is liberation, the goal of human existence. The liberation that results from the realization of Brahman is often described in the Upanishads:
He who knows this Brahman, the supreme, the immortal, set in the cave of the heart, my gentle friend, cuts the knot of ignorance in this very life.
"The purpose seved by the scripture," Shankara states, "is that it enables one to attain the knowledge of the identity of Atman with Brahman and thereby destroys grief and delusion, which are the result of ignorance." He quotes the mahavakyas, especially "Thou art that", to illustrate that brahman is not an outer reality that one comes to know, but rather one realizes that one's Self is the reality. This is why the Mundaka Upanishad says, "The knower of Brahman is Brahman itself". Brahman is the knower and known joined together, as described eloquently by professor Eliot Deutsch. "Brahman is that state which is when all subject/object distinctions are obliterated. Brahman is ultimately a name for the experience of the timeless plentitude of being." Brahman, the wholeness of unity and diversity, pierces the illusion of maya.
MAHARISHI MAHESH YOGI'S CONTRIBUTION TO THE UPANISHADS
Maharishi Mahesh yogi came from the Shankaracharya tradition of India. For 13 years he was a disciple of the Shankaracharya of Jyotirmath, Swami Brahmananda Saraswati. For 5 decades after that, Maharishi traveled the world, teaching the wisdom of the Himalayas to people from all walks of life and establishing educational institutions on every continent. Maharishi remarked, "It is my joy to make the difficult simple." This was his contribution in many areas of the literature, including the Upanishads. Maharishi has taken the ancient wisdom of the Upanishads and integrated it into a complete science of consciousness, available in a systematic and empirically based body of knowledge. He once said, "The study of the upanishad is the flow of our life."
For Maharishi, the Upanishads are fundamentally about the knowledge and experience of transcending, which he made available by bringing to light the Transcendental Meditation technique. Transcendental Meditation allows people to experience a state of pure consciousness, a state beyond thought in which the mind is awake, experiencing lively silence and nothing else. The Upanishads often mention this state of consciousness, which they call turiya chetana, or the fourth, because it follow the three better known states of consciousness: waking, dreaming and sleeping. Turiya is also known as samadhi in the Upanishads and especially in the literature of yoga. The Mandukya Upanishad speaks of this state of pure consciousness as "peaceful, benign, undivided --- that is known as the fourth. That is the Self. That is to be realized". This state is first realized during meditation, illustrating that the Upanishads offer not just a philosophy, but a description of direct experience. Because the fourth state of consciousness is measurable and repeatable, it is open to the systematic procedures of verification found in science.
Maharishi emphasizes that turiya is the gateway to higher states of consciousness. With regular practice of meditation, the fourth state of consciousness begins to be experienced simultaneously with the waking, dreaming and sleeping states of consciousness. Eventually, consciousness becomes a living reality --- one perceives every object of attention as pure consciousness. Maharishi describes this as Unity Consciousness, where there is an experiential unity between the perceiver and the object of perception, based on the initial experience of the Self in the fourth state of consciousness.
For Maharishi, Unity Consciousness means living a fully integrated life in activity. Like Shankara, Maharishi does not regard creation as an illusion, which was taught by some of Shankara's followers. Maharishi writes about the fate of Shankara's teaching at the hands of his followers: "The teaching became one-sided and, deprived of its wholeness, eventually lost its universal appeal. It came to be regarded as mayavada, a philosophy of illusion, holding the world to be only illusory and emphasizing the detached way of life."
Maharishi explains that for one who is experiencing unity, the world is brahman, not an illusion: "The world was a mirage only in so fas as it was experienced as different from one's Self." For those who are in the ordinary waking state of consciousness, the lack of holistic awareness produces experience dominated by diversity, but as Maharishi points out, "Once that lack is removed, the world of differences is the world of wholeness." Diversity may appear to be an obstacle at one stage of life, but from the reality of Unity consciousness, the variety of the world is an ever-increasing joy.
Maharishi emphasizes that the material creation is nothing other than consciousness itself. It is only in the state of ignorance that diversity appears to be distinct from that ultimate reality of brahman. In the state of enlightenment, the world is experienced and understood to be wholeness, Brahman. The illusion is not the existence of creation, but rather the illusion is the inaccurate perception that creation is separate from wholeness.
Brahman is unity. It is one reality composed of unmanifest and manifest existence. This fundamental principle of the Upanishads is found in the phrase, "That is full; this is full". Maharishi explains that "this and that," the unmoving and the moving, are two parts of existence:
The eternal texts of the Vedas, crowned with the philosophy of the Upaishads, reveal the relative and the Absolute as two aspects of the one reality, Brahman, absolute Being, which, although unmanifest in Its essential nature, manifests as relative creation."
According to Vedanta, the inherent nature of life is eternal bliss consciousness, which can be seen in a passage that Maharishi emphasized from the Taittiriya Upanishad: "Out of bliss these beings are born, in bliss they are sustained, and to bliss they go and merge again." The joy of life, the bedrock of the Upanishads, is also the essential message of Maharishi's teaching, as shown in one of this first books, The Science of Being and Art of Living, which says, "Expansion of happiness is the purpose of creation." He clearly states that life is essentially bliss in nature:
I hold that life is bliss. In essence life is not a struggle. Man is not born to suffer, but to feel joyful; he is born of bliss, consciousness, wisdom and creativity. Once the flower of life has bloomed in a man, then consciousness, wisdom and creativity are ever-present in him. When the inner (spiritual) and the outer (material) glories of life are consciously brought into harmony, then life is integrated and becomes truly worth living.
Perhaps Maharishi's greatest contribution to the Upanishads is to point out that they describe a living reality that can be experienced. They are an authentic record of the ultimate meaning of existence which is first experienced in turiya and later established in the state of Unity Consciousness. According to Maharishi, the purpose of the Upanishads is to offer a vision of the most profound truths of life and to inspire people to live these truths in their day-to-day life. Maharishi explains that upanishad, "sit down near," is the description of Unity Consciousness, because in that state everything sits down near the speaker, who perceives the infinite correlation between all things. In Unity Consciousness, everything is the Self, which the Upanishads describe as the living experience of seeing "all beings in the Self and the Self in all beings."
The Upanishads make clear that the highest realization is linked to the repeated experience of the fourth state of consciousness (turiya). For example, in the Shvetashvatara Upanishad, the sage Shvetashvatara describes how he realized unity "through the power of mediation and through the grace of God." First the Self is realized in isolation and then as the ultimate reality in all things. The Upanishads describe the person aspiring for unity as "using the nature of his own Self like a lamp to illumine the true nature of Brahman." The present translation of the Upanishads was undertaken with this reality in mind and heart.
--- Thomas Egenes
1. Isha Upanishad - The Inner Ruler
The Self is everywhere. Bright is the Self,indivisible, untouched by sin, wise, immanent and transcendent. He it is who holds the cosmos together 
"If all the Upanishads and all the other scriptures happened to be reduced to ashes, and if only the first verse in the Ishopanishad were left in the memory of the Hindus, Hinduism would live forever."
With those words Mahatma Gandhi paid tribute to the remarkable Upanishad that traditionally stands at the beginning of most Indian collections. It owes this priority to the poetic grandeur and stained profundity of its language, which in on 18 verses establish the fundamental building blocks of spiritual awareness.
The 5th-century Greek writer we know as Dionysius the Areopagite once said that as he grew older and wiser his books got shorter and shorter. He should have envied the sage of this Upanishad. In this intensity he does not mince words. The central section, verses 9-14, is what scholars called a "crux," or famously difficult passage. The transaction brings out its practical significance: materialism leads us to lose awareness of our inner life, which is bad enough; but to be hypnotized by our own feelings and sensations and forget about others and the world around us is worse. By living in awareness of both these worlds, we can rise above them toward the one Reality. With the last 4 verses we emerge onto the lofty plane, and the Upanishad takes on a tone of intense devotion that is rare even in later, God-centered mystical literature.
Each Upanishad comes with an invocation drawn from a traditional set. The invocation to the Isha is especially striking. Consistent with the condensed meaning of the Upanishad itself, it rings changes on a simple household word, "full" (purnam): in the inexhaustible Reality, the infinite of "that" world, the unseen, sends forth "this" world of infinite variety in which we live, without ever being diminished. The American poet Anne Sexton ay have been thinking of this haunting invocation when she wrote:
Then the well spoke to me. It said: Abundance is scooped from abundance yet abundance remains.
Spiritual economics begins not from the assumed scarcity of matter but from the verifiable infinitude of consciousness. "Think of this One original source," Plotinussand, "as a spring, self-generating, feeding all of itself to the rivers and yet not used up by them, ever at rest." Or, as Gandhi put it, "There is enough in the world for everyone's need; there is not enough for everyone's greed."
All this is full. All that is full, from fullness, fullness comes. When fullness is taken from fullness, fullness still remains.
OM shanti shanti shanti
2. The Katha Upanishad - Death as Teacher
When a person dies, there arises this count: "He still exists," say some; "he does not," say others. I want you to teach me the truth.[1.1.20]
If there is one Upanishad that can be called a favorite in all ages, it is the Katha. It is not hard to see why. Its theme, broadly, is the same as that of all the Upanishads: the deathless Self, the need for and the way to its realization; but the Katha is more successful than other Upanishads at describing this, in several ways.
The right questions are half the battle in life. In the Katha we have the right question in highly dramatic form; in fact we have a highly imaginative confrontation of the ideal theater (1.1. 22) and the ideal student (11.1. 4), and their identity is surprising: the latter is a teenager, and his teacher is death.
We must consider why. Nothing places the question "Who am I?" in such stark relief as the fact of death. What dies? What is left? What can we do about death now while we are still alive? Most social life seems a conspiracy to discourage us from thinking of these questions.
Nachiketa represents that rare type of awakened person in whom this presence, once glimpsed, can never go away. "Now that I have seen your face," he says to Death,"what can I enjoy?" Yet, rare as he is, he represents the capacity latent in all of us to face that grim awareness and use it as arrive to deepening consciousness.
In other Upanishads and throughout Indian literature allegory is a favorite device, but rarely is it more dynamic and successful than in the Katha. The opening narrative is an extended allegory which keeps spiritual depth and dramatic vividness in high suspense. Every detail has both immediate and transcendent reality. Nachiketa, who has more personality than most Upanishadic figures, asks, "What is death going to do with me, today?" But at the same time he universalizes his condition, which is in fact the most universal of human destinies: "I shall go to death, at the head of many more to follow..."
Nachiketa is an attractive character who cannot go along with sham; but he is not an obstreperous rebel; he is more sincere about convention than his after. At no time does he lack respect. By poking holes in society's shroud of complacency he represents what it would take to awaken any and all of us. He has shraddha: determined seriousness, a deep abiding, confident faith.
The Katha consistently lays stress on several practical themes of the spiritual life; that a spiritual theater is essential; that in all human experience it is really only the Self, that is the enjoyer, so that when one realizes the self "there is nothing else to be known' and all the knots that strangle the heart are loosened"; and of course that death occurs only to that part of us which was born and launched into separate existence. This Upanishad thus speaks to a longing which could not be deeper or more universal" as Donne put it, "Death shall be no more: Death, thou shall die!"
The Katha is also distinctive in explaining with the use of two very practical terms - that is between what is good and what is pleasant; in Sanskrit, between shreya and preya.
May the Lord of Love protect us. May the Lord of Love nourish us. May the Lord of Love strengthen us. May we realize the Lord of Love. May we live with love for all. May we live in peace with all.
OM shanti shanti shanti