Mahavakyas (महावाक्यानि)

Mahavakyas (sing.: mahāvākyam, महावाक्यम्; plural: mahāvākyāni, महावाक्यानि) are "The Great Sayings" of the Upanishads, as characterized by the Advaita school of Vedanta. They are:

1. Aham Brahmasmi (अहं ब्रह्मास्मि) (Brihadaranyaka Upanishad, 1:4:10, Yajurveda)
2. Ayam atma Brahma (अयं आत्माब्रह्म) (Mandukya Upanishad, 1:2, Atharvaveda)
3. Tat tvam asi (तत् त्वम् असि) (Chaandogya Upanishad, 6:8:7, Samaveda)
4. Sarvam khalvidam Brahma (सर्वं खल्विदं ब्रह्म) (Chaandogya Upanishad, 3:14:1, Samaveda)
5. Prajnanam Brahma (प्रज्ञानं ब्रह्म) (Aitareya Upanishad, 3:3, Rigveda)

Mahavakyas - Detailed Discussion

Aham Brahmasmi (अहं ब्रह्मास्मि)

(Brihadaranyaka Upanishad, 1:4:10, Yajurveda)

Literal Meaning: I am Brahman.

In the sentence (Aham Brahma asmi) or I am Brahman, the 'I' is that which is the One Witnessing Consciousness, standing apart from even the intellect, different from the ego-principle, and shining through every act of thinking, feeling, etc. This Witness-Consciousness, being the same in all, is universal, and cannot be distinguished from Brahman, which is the Absolute. Hence the essential 'I' which is full, super-rational and resplendent, should be the same as Brahman. This is not the identification of the limited individual 'I' with Brahman, but it is the Universal Substratum of individuality that is asserted to be what it is. The copula 'am' or (asmi) does not signify any empirical relation between two entities, but affirms the non-duality of essence.

Ayam atma Brahma (अयं आत्माब्रह्म)

(Mandukya Upanishad, 1:2, Atharvaveda)

Literal Meaning: This self is Brahman.

'Ayam' means 'this,' and here 'this-ness' refers to the self-luminous and non-mediate nature of the Self, which is internal to everything, from the Ahamkara or ego down to the physical body. This Self is Brahman, which is the substance out of which all things are really made. That which is everywhere, is also within us, and what is within us is everywhere. This is called `Brahman,' because it is plenum (poorna; पूर्ण), fills all space, expands into all existence, and is vast beyond all measure of perception or knowledge. On account of self-luminosity, non-relativity and universality, Atman and Brahman are the same. This identification of the Self with Absolute is not any act of bringing together two differing natures, but is an affirmation that absoluteness or universality includes everything, and there is nothing outside it.'

Tat tvam asi (तत् त्वम् असि)

(Chaandogya Upanishad, 6:8:7, Samaveda)

Literal Meaning: That you are

This Mahavakya occurs in the Chaandogya Upanishad. Sage Uddalaka mentions this nine times, while instructing his disciple Svetaketu in the nature of reality. That which is one alone without a second, without name and form, and which existed before creation as well as after creation, as pure Existence alone, is what is referred to as Tat or That. The term tvam stands for that which is transcendent to the intellect, mind, senses etc., and is the real 'I' of the student addressed in the teaching. The union of Tat and tvam is by the term asi , which means are. That Reality is remote is a misconception, which is removed by the instruction that it is within one's own self. The erroneous notion that the Self is limited is dispelled by the instruction that it is the same as Reality.

Sarvam khalvidam Brahma (सर्वं खल्विदं ब्रह्म)

(Chaandogya Upanishad, 3:14:1, Samaveda)

Literal Meaning: All this is the Brahman.

The entire universe is the Divine, which includes our self. The Divine is not only the consciousness principle in you and I, it is also the being principle in all things. It is the ultimate object as well as the in most subject in all beings. It is one and all and all in one. This statement is to be understood in its most concrete sense. When I am talking to a person, be it a friend or foe or stranger, I should believe that s/he is Brahman Itself who has put on that particular garb or form which appears to be limited.

Prajnanam Brahma (प्रज्ञानं ब्रह्म)

(Aitareya Upanishad, 3:3, Rigveda)

Literal Meaning: Consciousness is Brahman.

In the sentence, 'Prajnanam Brahma' or Consciousness is Brahman, a definition of Reality is given. The best definition of Brahman would be to give expression to its supra-essential essence, and not to describe it with reference to accidental attributes, such as creatorship etc. That, which is ultimately responsible for all our sensory activities, as seeing, hearing, etc., is Consciousness. Though Consciousness does not directly see or hear, it is impossible to have these sensory operations without it. Hence it should be considered as the final meaning of our mental and physical activities. Brahman is that which is Absolute, fills all space, is complete in itself, to which there is no second, and which is continuously present in everything, from the creator down to the lowest of matter. It, being everywhere, is also in each and every individual.