Etymologically the word means “sitting down near.” It is derived from Upa (near), ni (down) and sad (to sit).

Groups of pupils sit down near the teacher to learn from him the esoteric doctrine. Students sit at the feet of an illumined teacher in an intimate session of spiritual instruction, as aspirants still do in India today. Often the teacher is one who has retired from worldly life to an ashram or forest academy. He lives with students as a family, teaching in question-and-answer sessions and by example in daily living.

Source: Ekanath Easwaran, The Upanishads.
S. Radhakrishnan, The Principal Upanishads

The verse is part of Chandogya Upanishad, a dialogue between a son and his father. It says “There is nothing that does not come from him. Of everything he is the inmost Self. He is the truth; he is the Self supreme. You are that, Shvetaketu; you are that.”

This famous text emphasizes the divine nature of every human soul and how it contains the essence of the infinite or Brahman. It stresses the need to differentiate between the essential self and the accidents with which it is confused (name, family descent etc).

The picture is Sabarimala Temple with the Mahavakya Tat Tvam Asi.

Source: Eknath Easwaran, The Upanishads.
S. Radhakrishnan, Principal Upanishads

The number of Upanishads has been growing. Upanishads exceed 200, though Indian tradition puts it at 108. Muktika Upanishad lists all 108 Upanishads including itself. Ten of these are considered Principal Upanishads, though some recognize thirteen principal Upanishads. Shankaracharya has provided a commentary on all the ten Principal Upanishads and the Shvetashvatara Upanishad.

Source: S. Radhakrishnan, Principal Upanishads

Aham Brahmasmi is the core of Advaita philosophy that emphasizes that the soul and the Brahman are the same. It is from the Brihadaranyaka Upanishad, considered among the oldest Upanishads.

The Mahavakya says Brahman was the only being in the beginning. Therefore it knew itself only, as ” I am Brahman” or ” Aham Brahmasmi.” Therefore it became all. Whoever among the Gods became awakened to this, he indeed became Brahman too. It is the same in the case of seers, same in the case of men.

The picture is a Brihadaranyaka manuscript.

Source: S. Radhakrishnan, Principal Upanishads

Literally, Vedanta means end of Veda. Vedanta is from Ved and Ant, meaning end of Vedas. It means the destination of Vedic teachings or objectives. They are the conclusion as well as the goals of Vedas. Upanishads are the concluding portions of Vedas.

The chief reason Upanishads are called the end of Vedas is that they represent the central aim and teaching of the Veda. Upanishads represent the Jnana Kanda or knowledge portion of the Vedas. Vedanta is now used to represent the system of philosophy based on Upanishads.

Source: S. Radhakrishnan, Principal Upanishads

The Mahavakya establishes that “All reality is consciousness.” And the same consciousness is the life of all: thus we have the explanation for both the sanctity and the unity of life. It is from Aitareya Upanishad.

Earth, air, fire, water, and space; all creatures, Great or small, born of eggs, of wombs, of heat, Of shoots; horses, cows, elephants, men, and women; All beings that walk, all beings that fly, And all that neither walk nor fly. Prajna Is pure consciousness, guiding all. The world Rests on prajna, and prajna is Brahman.

Source: Eknath Easwaran, The Upanishads

Mahatma Gandhi said these words in a public address, “If all the Upanishads and all the other scriptures happened all of a sudden 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.”

Isha Vasyam Idham Sarvam means God pervades everything in the universe. The first two verses are also considered as the essence of Bhagavad Gita. The translation of the first verse is
“The Lord is enshrined in the hearts of all.
The Lord is the supreme Reality.
Rejoice in him through renunciation.
Covet nothing. All belongs to the Lord.”

The first line is also translated as Brahman pervades everything in the universe.

Source: Eknath Easwaran, The Upanishads.
C. Rajagopalachari, Upanishads for the Lay Reader

This is the invocation from the Taittriya Upanishad. The teacher and pupil pray for harmonious relation in a keen and vigorous study. This is recited generally before the start of a learning session or a group activity. The verse means

“May he protect us both together,
May he nourish us both together,
May we both acquire strength together,
Let our study be brilliant, May we not cavil at each other,
Aum, Peace, Peace, Peace”

Om saha nav avatu, saha nau bhunaktu, saha viryam karavavahai,
tejasvi nav adhitam astu, ma vidvisavahai, Om santih.

The picture is a Guru Sishya depiction by the legendary Maniam Selvan, Himalayan Academy

Source: Swami Gambhirananda, Advaita Ashrama, Eight Upanishads.

The mantra translates as ” from the unreal (or falsehood) lead me to the real (or truth), from darkness lead me to light, from death lead me to immortality.” Both unreal and darkness refer to death. Real and light refer to immortality.

This mantra is from Brihadaranyaka Upanishad.

“Asato ma Sad Gamaya,
tamaso ma jyotir gamaya,
mrtyor mamrtam gamaya”

Source: S. Radhakrishnan, Principal Upanishads

Anantam refers to infinite (also sometimes translated as bliss).The verse explains that Creation started from universal consciousness (Brahman). The verse says “Brahman is truth, knowledge and infinite.” It is from the Taittriya Upanishad.

“He who knows that Brahman is existing in the intellect, lodged in the supreme space in the heart, enjoys, as identified with the all-knowing Brahman, all desirable things simultaneously.”

From that Brahman, which is the self, was produced space. From Space emerged air. From air was born fire. From fire was created water. From water sprang up earth. From earth were born the herbs. From the herbs was produced food. From food was born man.

Source: Swami Gambhirananda, Advaita Ashrama, Eight Upanishads

The Shanti Mantra is part of Isha Upanishad. The verse means

” That is Infinite, this is infinite,
The infinite proceeds from the infinite,
Taking the infinite of the infinite, it remains infinite alone”

Purnam is also translated as fullness.

Om purnam adah purnam idam purnat purnam udacyate,
purnasya purnam Adaya purnam evavasisyate.

The picture is a Guru Sishya depiction by the legendary Maniam Selvan, Himalayan Academy.

Source: Swami Gambhirananda, Advaita Ashrama, Eight Upanishads

Katha Upanishad demonstrates how Upanishadic wisdom could arise from both the wise and the young.

In a fit of irritation, Vajasravasa gave away his young son Nachiketa to death. Abiding by his father’s words, Nachiketa goes to meet Yama without the fear of death. The young Nachiketa insists on Yama teaching him the meaning of soul (or I) and what happens after death. Yama is reluctant to explain and instead offers him and offers him wealth, life and power.

Nachiketa refuses, arguing that when I have seen you (death) and since you will take everything away at the end, what use are these material possessions to me? Who better to teach me about soul and death than you, Yama?

Katha Upanishad captures their dialogue on Self and Death. It is a dramatic question posed by a fearless teenager hungry for wisdom to the ideal teacher, death itself.

The picture is from Rameswaram depicting Yama teaching Nachiketa.

Source: Eknath Easwaran, The Upanishads.