1. Tat Tvam Asi (तत् त्वम् असि) – "Thou Art That" Source: Chandogya Upanishad (6.8.7)

"Tat Tvam Asi" is one of the most powerful Mahavakyas, emphasizing the unity of the individual soul (Atman) with the Supreme Reality (Brahman). It is a declaration of non-duality, asserting that the individual self is not separate from the cosmic existence but rather an integral part of it.
tat tvam asi, in Hinduism, the famous expression of the relationship between the individual and the Absolute. The statement is frequently repeated in the sixth chapter of the Chandogya Upanishad ( c. 600 bce) as the teacher Uddalaka Aruni instructs his son in the nature of brahman, the supreme reality. The identity expressed in this judgment was variously interpreted by the different darshans (schools) of the orthodox philosophy of Vedanta. The phrase was given its most literal interpretation by the 8th–9th-century thinker Shankara of the Advaita (Nondualist) school, for whom the statement was one of the great assertions fundamental to his doctrine.

Philosophical SignificanceThis Mahavakya is a direct assertion of Advaita Vedanta, which negates dualism between the creator and creation. The phrase is addressed to a disciple by his guru, teaching that the self is identical with the infinite, all-pervading consciousness. When fully understood, this statement dissolves the illusion of separateness and ego, leading to self-realization.

Application in Spiritual PracticeMeditation on "Tat Tvam Asi" leads to the dissolution of the false identification with the body and mind, allowing the seeker to experience their true divine nature. This realization removes ignorance (Avidya) and liberates the individual from the cycle of birth and death (Samsara).

2. Aham Brahmasmi (अहं ब्रह्मास्मि) – "I Am Brahman" Source: Brihadaranyaka Upanishad (1.4.10)

Aham Brahmasmi is from the Brihadaranyaka Upanishad, found in Yajur Veda. As one of the Principal Upanishads, Brihadaranyaka Upanishad is one of the oldest scriptures in Hinduism, and is considered to be an ancient source of spiritual wisdom. This text represents the Advaita Vedanta branch of Hindu philosophy and provides a treatise on the concepts of Atman and Brahman.
"Aham Brahmasmi" is another foundational Mahavakya that declares the identity of the individual soul with Brahman. It is a first-person affirmation of the truth that the self is not limited to the body or mind but is, in essence, the infinite consciousness itself.
Representing a central theme of Advaita philosophy, Aham Brahmasmi unites the macrocosmic ideas of God and universal consciousness with the microcosmic individual expression of the Self. This mantra highlights the notion that all beings are intimately connected to universal energy and cannot be separated from it. To recite Aham Brahmasmi is to recognize that Brahman and Atman are one, and as such, there can be no ego or sense of separation.

Philosophical SignificanceThis Mahavakya is a key statement in self-inquiry (Atma Vichara). It eliminates the misconception that Brahman is an external entity separate from oneself. By affirming "I am Brahman," the seeker directly acknowledges their divine essence.

Application in Spiritual PracticeRepeating and meditating upon "Aham Brahmasmi" fosters deep inner contemplation. It is a mantra of empowerment, reminding individuals that they are not mere mortals but embodiments of the supreme consciousness. This realization leads to liberation from worldly suffering and ignorance.

3. Prajnanam Brahma (प्रज्ञानं ब्रह्म) – "Consciousness is Brahman" Source: Aitareya Upanishad (3.3)

"Prajnanam Brahma" establishes that ultimate reality is not a mere philosophical construct but the very consciousness that illuminates all experience. This Mahavakya asserts that Brahman is pure awareness, the substratum of existence.
The Sanskrit word Prajna means consciousness. The consciousness is Brahman. This is the meaning of Prajnanam Brahma.

According to Guru Gita, it is Upadesa Vakya, the statement of instruction or guidance. Some call this Mahavakya Lakshana Vakya, the statement that depicts the nature of Brahman.

Etymologically, Pra means Supreme. Jnana means Knowledge or wisdom or awareness or consciousness. We may also take the meaning as the supreme knowledge is Brahman.

Who am I? I am not the body. Likewise, I am not the mind. I am not the sense organs. If I go on negating like this, only the consciousness remains. That consciousness is Brahman. This is the meaning of this Mahavakya.

Philosophical SignificanceUnlike materialistic interpretations of the universe, this statement from the Upanishads reveals that true reality is not external matter but the conscious principle that perceives, understands, and experiences existence. Consciousness is not an emergent property of the brain but the fundamental reality from which all phenomena arise.

Application in Spiritual PracticeBy meditating on "Prajnanam Brahma," one learns to detach from the fleeting nature of physical existence and align with the eternal awareness that is Brahman. This insight transforms perception, allowing seekers to view the world as an expression of the divine rather than as a separate, materialistic entity.
The Interconnection of the Three MahavakyasEach of these Mahavakyas provides a different perspective on the same ultimate truth:
"Tat Tvam Asi" directs the seeker to recognize their unity with the infinite.

"Aham Brahmasmi" internalizes this realization as personal truth.

"Prajnanam Brahma" defines Brahman as the very consciousness that enables this understanding.

Together, they dismantle the illusion of separateness and guide seekers toward self-liberation through deep contemplation and realization.
The Relevance of Mahavakyas in Modern LifeIn a world dominated by materialism, stress, and external distractions, the wisdom of the Upanishads offers a pathway to inner peace. The Mahavakyas encourage individuals to rise above ego-driven pursuits and embrace their eternal, boundless nature. Their teachings are not limited to ascetics but are relevant for anyone seeking clarity, purpose, and spiritual fulfillment.
Unlocking the Ultimate TruthThe Mahavakyas from the Upanishads serve as profound gateways to self-realization. They invite seekers to transcend limitations, dissolve the illusion of separateness, and embrace their true divine nature. By meditating on these great sayings, one embarks on a transformative journey toward enlightenment and eternal bliss.
Understanding and internalizing the essence of "Tat Tvam Asi," "Aham Brahmasmi," and "Prajnanam Brahma" can lead to profound shifts in perception, ultimately guiding one toward the realization of absolute truth—the oneness of all existence.