Synopsis of Kena Upaniñad
This Upaniñad explains the Supreme, but without revealing His personality directly. The Upaniñad is in fact named after its first word, kena ("by whom?"), which is grammatically in an "oblique" case. The Supreme is "obliquely" revealed as the inspirer and controller of all the functions of the mind and senses and of the demigods. Although it is not unequivocally said here that Brahman is personal, it does show its own power to reveal itself and create success for individual persons.
There are four chapters totalling 34 verses and short prose paragraphs.

1	The Supreme, Brahman, is unknown to the mind and knowledge-acquiring senses. They gain their access to knowledge through Brahman.
Real knowledge is of Brahman, not of what we see in this world.

2	Brahman can be known only partly.
One who thinks he knows Brahman completely doesn't, while one who recognizes that he doesn't know Brahman completely actually knows something about Brahman.

3	Story of Brahman exhibiting Himself as a mysterious person (a Yakña) to the demigods and proving Himself greater than them by showing that they are powerless in His presence.

4	Those who know Brahman as He has revealed Himself are superior. The greatest demigods are those who knew Him first.
For success in life He should be worshiped, and self-purification is needed for this purpose. One who knows Him will attain real happiness in the spiritual world.

Synopsis of Kaöha Upaniñad
This Upaniñad explains the secret of eternal life beyond death, as explained by Yamaräja himself to the young brähmaëa boy Naciketä. Only one who has no interest in material things can understand this topic properly. By understanding the distinct identities of the jéva soul and Supreme Soul, one can become self-controlled, give up material desires, and attain spiritual perfection.
There are six chapters totaling 119 verses.

1.1 	Naciketä was only five years old but spiritually advanced.
His father gave away everything he owned during a sacrifice and had nothing left to pay the priests.
Naciketä asked him, "Who will you give me to?"
Annoyed, his father told him, "I give you to death!"
Naciketä went to Yamaloka, but Yamaräja was not home.
Only the women of the family were home, so Naciketä had to wait at the door. He stayed their fasting for three days.
Yamaräja came home, apologized, and offered any three benedictions.
Naciketä's first choice: His father won't be upset and will be happy to see him come home.
Second choice: How to perform the agnicayana sacrifice for attaining liberation.
Third choice: An explanation of whether after liberation a person still exists as an individual person or not.
Yamaräja tried to dissuade Naciketä from asking this third benediction, and offered various enticements.
Naciketä insisted.

1.2	Yamaräja gives instructions as fulfillment of third boon (rest of the Upaniñad).
Only the most intelligent person (like Naciketä) will ask about this. Most people are proud fools and come to Yamaräja again and again.
Those who know the Supreme Lord in the heart become free from material happiness and distress. They hear from bona fide authorities and practice adhyätma-yoga.
The soul (indifferently the jéva or Paramätmä) is eternal and situated in all living bodies.
It is smaller than the smallest and greater than the greatest.
One can see the soul's glory only by the Supreme Lord's mercy.

1.3	There are actually two souls in the heart, the jéva and the Paramätmä.
The jéva soul is the driver of the body-chariot. His senses are the horses and his mind is the rope.
One who has realized spiritual knowledge controls his senses and attains the Paramätmä's abode (tad viñëoù paramaà padam).
He is not born again. One who cannot control his senses fails to attain this liberation, but remains in the cycle of birth and death.
The sense objects are superior to the senses, the mind is superior to the sense objects, intelligence is superior to the mind and the self is superior to intelligence.
One should take the opportunity of human life seriously. Spiritual life is like a razor's edge.

2.1	Lord Brahmä made the senses on the outside of the body; therefore people perceive outward rather than inward. Only a rare person will turn his attention inward, desiring immortality.
The Supersoul inspires the sensory activities of the jévas in all states of consciousness.
He also controls all the demigods.
One who fails to see this unity must die again and again.
One who realizes the Supersoul in the heart, the size of a thumb, brilliant like a fire without smoke, is freed from envy.

2.2	A liberated soul leaves his body for the last time.
It is not actually by the vital airs that one lives, but by Him on whom everything rests.
The Supersoul is in everyone's heart and supplies everyone's needs without becoming entangled.
The Supreme Soul in all creatures is the one controller. Although one in form, He expands Himself unlimitedly. Those wise persons who realize Him in the heart attain eternal peace; no one else does.
He is the supreme eternal living being among all eternal living beings who supplies the needs of all the others.
There are no material lights in spiritual world, but by the light of that place this whole world is illuminated.

2.3	The eternal banyan tree of Brahman has its roots upward and its branches downward. All the worlds are situated within it, and nothing exists apart from it.
Out of fear of Brahman fire burns, the sun shines, and Indra, Väyu and Death hurriedly do their duties.
If in this world one can understand the Supreme before giving up one's body, one can take his eternal body in the spiritual world.
The mind is superior to the senses, one's higher nature is superior to the mind, the (jéva) self is superior to that, and the unmanifest Supreme is superior to the self. Greater still than the unmanifest Supreme is the all-pervading Puruña. Knowing Him, a conditioned soul is liberated.
No one has seen His form with ordinary eyes, but those who have seen Him by meditation in their hearts have become immortal.
One becomes liberated by knowing that everything is under the shelter and control of the Supersoul, and by giving up material desires.
Synopsis of Praçna Upaniñad
This Upaniñad is in the form of questions and answers. The rather esoteric discussion focuses on the source and controllers of creation and how to attain perfection. It will take some careful explaining to make this text clearly understandable for modern readers.
There are six chapters totaling 67 prose paragraphs and verses.

1	Six sons of sages approached Pippaläda to ask questions. He told them to first practice austerities for one year, after which he will answer if he can.
Kabandhé Kätyäyana asked: What is the source of all creatures?
Answer: The Lord of creatures (Prajäpati) meditated and a conjugal pair arose, Rayi and Präëa. They generated creatures. Rayi is prakåti and Präëa is puruña.
Those who follow Prajäpati and beget children can go by path of Pitäs to moon, but those who are celibate and are completely honest can go by path of devas to Brahmaloka.

2	Bhärgava Vaidarbhé asked: How many gods control the creatures? Which one of the gods is the greatest, illuminating the universe?
Answer: Pippaläda lists the deities of the elements and senses.
Präëa is the greatest of the gods. When präëa is in the body all the other devas (senses) are established, but when he leaves they are all forced out.
Everything has präëa as its foundation, including fire, the sun, rain, the Vedas, the kñatriyas and brähmaëas, and Indra and Rudra.
Präëa controls everything in the three worlds, protects like a mother her children, and bestows opulence and wisdom.

3	Kauçalya Açvaläyana asked: Where is this präëa born from? How does it enter the body, maintain it and leave?
Answer: This is a very good question, so you must be dedicated to the Supreme.
Präëa is born from the ätmä.
Präëa engages the other senses like a king controlling subordinate administrators.
The ätmä is in the heart, surrounded by 101 subtle nerves which subdivide into thousands.
By piety one goes to higher worlds, by sin to sinful worlds, by a mixture to the world of humans.
The sun is the external präëa, giving life to the sense of sight.
Earth, sky, wind are secondary präëas.
One who knows the adhyätma (in the body) understanding of präëa enjoys immortality.

4	Sauryäyaëé Gärgya asked: Which devas (senses) stay awake when one is asleep? In which deva are all the others established?
Answer: Everything becomes one in the supreme deva, the mind, just as all the sun rays merge into the sun when it sets.
During sleep the präëa-fires stay awake. 
In deep sleep all the devas remain established in the Paramätmä.
The vijïänätmä (jéva) is the seer, toucher, hearer, etc. He is established in the infallible Paramätmä.
The Paramätmä has no material body and is infallible, but He is omniscient and is everything.

5	Çaibya Satyakäma asked: What world does one gain if he chants om at the time of death?
Answer: If one chants om for only one third of its proper duration, he takes birth in the world of humans and enjoys the opulences of celibacy and faith.
If one chants it for two-thirds of the right duration, he takes birth in the middle heaven to enjoy the opulences of the Moon.
If he chants it for the full duration, thus meditating on the Supreme Person, he takes birth in the sun. He then becomes free of all sins, attains the spiritual world and sees the Supreme Person, the Supersoul.

6	Sukeça Bhäradväja asked: Who is the sixteen-part Puruña? Where does he live?
Answer: He lives inside the body, and these sixteen expansions appear in him.
The jéva is this enjoyer of the sixteen expansions, namely präëa, faith, ether, air, fire, water, earth, the senses, the mind, food, vital strength, austerities, mantras, Vedic duties, worlds to be achieved by such duties, and identities assumed in these worlds.
One who understands this Puruña does not suffer the pangs of death.
         
Synopsis of Muëòaka Upaniñad
This Upaniñad describes the higher understanding of Vedic knowledge. Vedic rituals lead to perfection when performed with faith and knowledge, but not when one is attached to material results. To learn the higher truth, one who is broad minded and has become disinterested in material things must humbly approach a qualified spiritual master. Spiritual discipline should be practiced with realization of the Supreme Puruña as one's goal. It is important to appreciate the distinction of jéva soul and Supersoul. With the perfection of spiritual endeavor, one enjoys the fulfillment of all desires and goes to the spiritual world.
There are six chapters totaling 64 verses and prose paragraphs.

1.1	Çaunaka asked Aìgirä: What is it, knowing which everything is known?
Answer: There are two kinds of knowledge, superior and inferior.
The inferior knowledge is the Vedas and Vedic supplementaries.
The superior knowledge is that by which on understands "the infallible" (akñara).
The akñara is inaccessible to the senses, eternal, and infinite, but wise sages do see it, realizing it as the infallible source of all existence.
Everything comes from the akñara, as a spider spins its web, as herbs grow from the earth and as hair and nails grow from a living person.
The akñara is omniscient and creates everything from the "tapas" of its own intense thought.

1.2	The path of Vedic sacrifice was expanded in Tretä-yuga as the means for achieving truth and the world of the pious.
One who fails to do Vedic sacrifice is ruined.
One who properly does Vedic sacrifice is carried by the flames of the sacred fire to Brahmaloka (the spiritual world), where the master of the gods lives.
But the ritualistic process is unreliable. The sacrifices are "unfirm boats."
Those who think that ritual performances are perfection in their own right remains in the cycle of birth and death.
Those who are wise become renounced and go to live in the forest. By the path of the sun they go to where the immortal Puruña lives.
A real brähmaëa should realize that the benefits gained in this world by ritual sacrifice are temporary. He should become uninterested in these benefits and humbly approach a guru to find out the true meaning of sacrifice (tad-vijïänärthaà sa gurum eväbhigacchet).
The guru will explain the Absolute Truth to a qualified disciple.

2.1	The Puruña is everywhere, unborn, without material senses or mind, and beyond material nature.
Everything is generated from Him--the mind and senses; the elements of matter; the sun and moon; all living creatures; the Vedas and sacrifices; the demigods; austerity, faith, brahmacarya and Vedic regulations; the seven vital airs, seven sacred fires, seven sacrifices and seven worlds achieved by them; the oceans, mountains and rivers; the plants and their saps.
One who realizes this Puruña in the heart unties the knot of ignorance.

2.2	The Absolute is the target that one must aim at. One's bow is the knowledge of the Upaniñads. The sharp arrow is one's meditative worship.
Or, om is the bow and one's own self is the arrow; one should make oneself one-aimed like a sharp arrow.
One should understand that upon which everything is established, and give up all other talk. This is the "bridge to immortality."
When one has realized the Supreme, the knots of the heart are cut, all one's doubts are dispelled and one's karmic entanglement dissolves.
The pure Supreme is found in the "golden vessel" of the heart.
There are no material sources of light there, but by its light everything in this world is illumined.

3.1	There are two birds sitting on the tree of the body. One of them is trying to eat the fruits of the tree, and the other is just watching. The first bird is suffering, but when he turns his attention to the other bird, he will be freed from this unhappiness.
One who realizes the "golden" Puruña relieves himself of piety and impiety and becomes one in quality with Him.
Knowing the Supreme, the source of life in all, one becomes satisfied within.
The Supreme Soul is realized by truth, austerity, correct knowledge and brahmacarya.
The senses, speech, austerities and Vedic performances cannot reach Him, but one whose heart is purified by knowledge can see Him.
A successful knower of the Supreme has all his desires fulfilled.

3.2	Those with material desires take birth in various situations, but those who are finished with material desire can worship the Supreme and transcend material life.
The Supreme Soul is not realized by theoretical discussions, mental effort or studying many scriptures. But to one whom the Supreme Soul chooses to favor, He reveals His personal form.
Without developing spiritual strength one cannot realize the Supreme Soul.
By following the appropriate methods one can realize Him.
Sages who were satisfied by spiritual knowledge and free from material desire entered the Supreme's transcendental nature. They fixed their intentions by understanding of Vedänta, by sannyäsa and by self-purification. After death, they went to the spiritual world.
One who understands this Brahman also becomes Brahman, and none of his descendants will be ignorant of Brahman. He will transcend suffering and sins, becoming liberated and immortal.
Synopsis of Mäëòükya Upaniñad
This Upaniñad is an esoteric explication of the syllable om in relation to the four levels of consciousness.
There are 12 prose paragraphs.

The vibration om is everything--past, present, future and beyond time.
It has four parts, representing the four levels of consciousness.
The letter a represents waking consciousness, called Vaiçvänara, which enjoys gross matter. Realizing it, one fulfills all his desires.
The letter u represents dreaming consciousness, called Taijasa, which enjoys inner pleasures. Realizing it, one's knowledge becomes perpetual and one joins the liberated souls. None of his descendants will be ignorant of the Supreme. 
The letter m represents deep sleep, which is merged in "änanda" without seeing or dreaming anything. Realizing it, one can understand everything that exists and enters into union with the Supreme.
The fourth part is unmanifest. It is the ätmä. Realizing it, one's ätmä enters the supreme ätmä.
Synopsis of Taittiréya Upaniñad
After an introductory section presenting meditations and prayers for the success of transcendental study, this Upaniñad describes the soul-body relationship on five levels (the famous five-koça theory). The ultimate Soul of souls is presented as änanda, the reservoir of pleasure who gives life and pleasure to the jéva souls, and as rasa, by knowing whom one becomes full of pleasure.
There are three chapters totaling 86 prose paragraphs.

1. Çikñä-vallé (preliminary teachings)

Çikñä as study of pronunciation
Explanation of saàhitä (connections) in five divisions
adhilokam (mundane): earth combines with heaven (dyau), their combination is sky (äkäça), the combining agent is air.
adhijyautiñam (celestial): fire combines with sun, their combination is water, the combining agent is lightning.
adhividyam (educational): teacher combines with student, their combination is education, the combining agent is discussion.
adhiprajam (procreational): mother combines with father, their combination is offspring, the combining agent is procreation.
adhyätma (personal): lower jaw combines with upper jaw, their combination is speech, the combining agent is the tongue.
Prayer for fit senses for studying.
Prayer for material facilities.
Prayer for obtaining students.
Meditation on the vyähåti invocation: bhür bhuvaù suvaù.
Meditation on golden Puruña in the sky within the heart.
Glories of om.
Qualifications for study and teaching: truth, austerity, self-control,  sacrifice, hospitality, etc.
Instructions to student: Speak the truth, execute duty, etc. Worship your mother, father and guru. Follow the example of great brähmaëas and take advice from them.

2. Änanda-vallé (Explanation of spiritual ecstasy)

One who knows Brahman attains perfection. Brahman is truth and knowledge, unlimited. One who realizes it within the heart enjoys the fruits of all desires in the company of Brahman.
Ether arose from the supreme ätmä, and the other elements one after another.
The visible person is made of food and vital fluids (anna-rasa-maya).
There is a second person who ensouls him, the präëa-maya person of the vital air.
He is ensouled by the third person, the mano-maya person of the mind and Vedic duties.
He is ensouled by the fourth person, the vijïäna-maya-puruña who is the jéva.
The jéva is ensouled by the fifth person, the änanda-maya Supreme Person.
Why are some people liberated after death while others return to this world again?
The Supreme Person is the original, unmanifest cause of creation (asat).
He created manifest existence (sat).
He is rasa. One who attains Him as rasa becomes full of bliss.
If He weren't the reservoir of änanda, how could any life exist?
He gives life and änanda.
One who realizes Him attains fearlessness, but one who realizes only material things separate from Him remains in fearfulness.
The wind, sun, fire, Indra and Death all do their duties out of fear of Him.
There are different levels of änanda, that of ordinary human beings, that of various degrees of Gandharvas and demigods, and ultimately that of the Supreme Person. His änanda is beyond the description of ordinary words and thought, but one who understands Brahman as änanda no longer has any fear.

3. Bhågu-vallé (Bhågu's talks with his father)

Bhågu goes to his father Varuëa and asks to be taught about Brahman.
Varuëa proposes that Brahman is "food;"
Bhågu meditates on this, realizes how Brahman is food, but goes back to his father and asks him about Brahman again.
The exchange is repeated as Bhågu is told to meditate on each of the higher realizations of Brahman, up to realizing Him as änanda.
It is then said that one should not hold "food" in contempt, because it is nondifferent from the vital air on which the body is established.
"Food" is also water, on which the element fire is established. It is also earth, on which the sky is established.
The same Puruña found inside a person's heart is also found in the sun.
One who understands this realizes each of the five puruñas, culminating in realization of the änanda-maya Puruña.
Then one travels freely, enjoying whatever "food" he likes.
He goes about singing ecstatic praises of the Supreme in Säma Veda musical form: "Ah, I am food. I am the enjoyer of food. I am the maker of praise. I am the firstborn of Truth, born before all the gods..."
Synopsis of Aitareya Upaniñad
This Upaniñad describes the creation of the material world by the supreme ätmä. By His own desire He created the worlds, their controllers and their food. That creator should be worshiped because He is the source of all consciousness and the ultimate controller of everyone's senses.
There are five chapters totaling 33 prose paragraphs.

1.	In the beginning, the supreme ätmä was alone. Nothing else was manifest. The ätmä looked and thought, "Let me create worlds."
He created the elements, looked at them and decided, "Let me create controllers of the worlds." He made a person from the waters. This person underwent heating, and a mouth appeared in him. From this mouth came speech, and from speech fire. The person's nostrils appeared, from which came präëa. (and so on)

2.	The created demigods experienced hunger and thirst, and asked for a place of residence where they could eat to satisfy these urges.
The creator brought them a cow and then a horse, but they weren't satisfied with either. Then He brought them a man, which they were satisfied with and entered.

3.	The supreme ätmä looked and thought, "Let me create food for these worlds and their controllers." He made food appear from the waters.	
Each of the senses tried to take the food--speech, präëa, sight, hearing, touch, procreation and excretion--and because each could not, we cannot eat simply by mentioning food, smelling it, etc.
The downward air (used in swallowing) was finally able to take the food.
Then the ätmä entered the body to become the Supersoul within.

4.	A person's first birth is when the father places his semen in the mother.
Because one places his own self, so to speak, in his wife, therefore one should never do harm to one's wife.
One's second birth is when one comes out of the mother's womb.
One's third birth is when one has lived one's life, gotten old, died, and takes birth again in a new body.

5.	Who is the supreme ätmä whom we should worship? He by whose agency one' senses function.
This ätmä is consciousness. Consciousness goes by many names, but ultimately it is the Supreme, Brahman.
Synopsis of Çvetäçvatara Upaniñad
This Upaniñad identifies the source of creation and sustainer of all life as the Supreme Personality of Godhead. The jéva is distinct from Him because he is not the supreme controller and can fall into ignorance. To realize the Supreme Person, one should practice meditation and practical devotional service with implicit faith in the Lord and in one's spiritual master. The Supreme Lord is named Rudra here, but the glories described are obviously those of Lord Viñëu.
There are six chapters totaling 113 verses.

1.	What is the source of creation, Brahman, from which we are born, by which we live and to which we return?
Some say it is time, personal nature, fate, chance, etc.
The sages meditated and saw the Supreme's personal energy, which underlies the manifestation of time and the living selves.
The Supreme gives life to all and sustains all. Under its control, the living beings wander about in illusion.
When one realizes one's own self and his controller as separate, he then attains immortality.
The éça maintains everything--fallible and infallible, manifest and unmanifest--while the living entity is not in control but is bound up by the enjoying spirit; when he realizes the Supreme Lord he is freed from all entanglement.
There are two unborns, one in knowledge and one in ignorance.
There is also the unborn female, material nature, providing the objects of material enjoyment.
Perfection is achieved by understanding Brahman in these three distinct features.
One should practice meditation, making oneself the lower wood block for churning the sacred fire (araëi), om the upper araëi block, and meditation the churning rod. That way one can come to see the hidden Lord, who is all pervading like the oil in seeds, the water in rivers, the fire in the araëi blocks, and the ghee potentially contained in milk.

2.	(Verses from the Yajur Veda describe the focusing of the mind in devotional meditation.)
By the impulse of Savitä (the inspiring Supreme) one realizes the Supreme.
One should practice meditation--sitting straight, placing the senses within the heart, checking the movement of the vital airs, and concentrating without deviation.
One will experience gradually realizations of Brahman, each more and more distinct.
One will become free from disease, and one will smell good and pass little stool.
One will realize himself and then the Supreme, thus becoming free from all bondage.

3.	The one Lord rules everything. He is called Rudra. Those who know Him become immortal.
His eyes, mouths, arms and feet are everywhere. He generates the sky and earth. He is the source of the demigods.
He is hidden in the hearts of every living being, and is realized by devotional meditation.
Knowing Him, one transcends death, and there is no other path of liberation.
Nothing is greater than Him, and nothing is smaller than Him.
(Several verses are quoted from the Puruña-sükta.)
Although He has no feet or hands, He travels swiftly and takes hold of everything.
He sees without eyes and hears without ears.
He knows everything, but no one knows Him.
He is known by His own mercy.

4.	He is Himself all the demigods. He is a woman, a man, a boy, a girl, an old man hobbling with a cane.
All the worlds are born from Him.
There is a female goat (ajä) who gives birth to offspring who are red, white and black. One male goat (aja) is trying to enjoy her, while another male goat has given up enjoying her.
There are two friendly birds sharing the same tree.
One of them is eating the tree's fruits while the other just watches.
The bird who forgets his Lord is bewildered and suffers, but when he takes note of the other bird, the Supreme Lord, he regains his true glory and is freed from distress.
If one does not know Him, what is the use of his Åg Veda mantras? One who knows Him has actually realized the Vedic mantras.
Nature is Mäyä, and the Supreme Lord is the possessor of Mäyä.
Realizing Him as the indwelling Lord in all hearts, one attains complete peace.
No one has seen His form with ordinary eyes, but those who have seen Him by meditation in their hearts have become immortal.

5.	In ancient times Brahmä, demigods and sages realized Him and became devoted to Him and immortal.
Situated in everyone's heart, the Supreme Lord gives each person the results of their actions.
He manifests the three modes of nature and the three paths of life.
He is the size of a thumb and brilliant like the sun.
The countless jévas are each one ten-thousandth the size of the tip of a blade of hair.
The jévas appear as male and female and with other distinctions according to the various bodies they assume.
They appear in various species, great and small, accepting various combinations of the material modes.
The Supreme Lord has no material shelter.
He accepts a person's inner intentions.
He creates material life and liberation, and is the producer of time.
Those who know Him give up their connection with material bodies.
	
6.	Sages who are bewildered say that material laws or time are the ultimate controller, but actually it is the Supreme Lord's power which makes the world move.
He pervades everything in existence, knows everything and controls everything through time. The laws of karma act under His authority.
One should engage all one's work in the service of the Lord, and when one's karma is used up He can join the Lord.
He is the promulgator of religion, the dispeller of sins and the Lord of all opulences.
He is the Supreme Lord of all lords, the Supreme Deity of all deities,
the master of all masters. 
He has no duty or need to take help from material instruments.
No one is equal to Him or greater than Him.
He possesses manifold, autonomous energies of knowledge, power and activity.
That one Lord is hidden in every creature's heart, supervising the laws of karma. He is the witness of all action, alone and aloof from the material modes.
Only those wise souls who see Him within the heart attain eternal happiness, no one else.
He is the supreme eternal living being among all eternal living beings who supplies the needs of all the others.
In His abode no material lights shine, but by His effulgence everything in this world is illuminated.
In the beginning He generated Brahmä and taught Him the Vedas.
He gives enlightenment from within the heart.
Desirous of liberation, I (Çvetäçvatara Åñi) take shelter of Him.
To one who has implicit devotion for the Supreme Lord and equal devotion for one's spiritual master, all the meanings of these statements are revealed.