What is OM According to the Mandukya Upanishad? The Sacred Syllable Explained

Introduction: The Sound That Is the Universe

Among all the sacred sounds in Hinduism, one stands out as the most profound, the most ancient, and the most powerful: OM (also written as AUM). Chanted at the beginning and end of prayers, meditations, and rituals, OM is considered the primordial sound — the vibration from which the entire universe emerged. But what is OM, really? Is it just a syllable? A mantra? A symbol? The Mandukya Upanishad, the shortest of the principal Upanishads (only 12 verses), provides the most complete and profound answer. It declares: OM is this whole universe. OM is the Self (Atman). OM is Brahman.

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This article explains what OM is according to the Mandukya Upanishad — its literal meaning, its correlation with the four states of consciousness, and its use as a tool for Self-realization.

The Opening Declaration: OM is All This

The Mandukya Upanishad begins with a bold and uncompromising statement:

“OM — this syllable is all this. An explanation of it: all that is past, present, and future is, indeed, OM. And whatever else there is beyond the three times — that also is OM.”

This is not a metaphorical statement. It is not saying that OM represents the universe or that OM symbolizes the universe. It is saying that OM is the universe. The syllable OM and the totality of existence — past, present, and future — are identical. Not only the manifest universe of time and space, but even that which transcends time (Brahman itself) is OM.

This is the foundation of the Mandukya Upanishad’s teaching. To know OM is to know everything. To meditate on OM is to meditate on the very fabric of reality. To realize OM is to be liberated.

The Four Parts of OM: A, U, M, and Silence

The Upanishad then analyzes the syllable OM into its four parts. In Sanskrit, OM is written as AUM. These three letters — A, U, M — are not separate sounds. They flow into each other: A emerges from the throat, U rolls forward, and M closes at the lips. After M, there is silence.

Part	Sound	State of Consciousness	Name of State	Description
First	A	Waking	Vaishvanara	Aware of external objects
Second	U	Dreaming	Taijasa	Aware of internal objects
Third	M	Deep Sleep	Prajna	No objects; blissful ignorance
Fourth	Silence	Fourth (Turiya)	Atman	Pure, non-dual consciousness

Each part of OM corresponds to a state of consciousness. And each state of consciousness is a manifestation of the one Self.

First Part: A — Waking State (Vaishvanara)

The Upanishad says:

“The first quarter is Vaishvanara (the waking state). Its sphere is the waking world. It is conscious of external objects. It has seven limbs and nineteen mouths.”

The sound A (pronounced “ah”) is the first sound, emerging from the throat without any closure. It represents the waking state (Jagrat), where consciousness is turned outward, aware of external objects through the senses.

Characteristics of the waking state:

• Aware of the external world through the five senses
• Identifies with the physical body
• Experiences time, space, and causality
• Believes the world is ultimately real

How to experience the “A” of OM: When you chant OM, feel the “A” as the opening, the beginning, the outward-moving energy. It is like the dawn, the start of the day, the waking of consciousness to the world.

Second Part: U — Dreaming State (Taijasa)

The Upanishad says:

“The second quarter is Taijasa (the dreaming state). Its sphere is the dream world. It is conscious of internal objects. It has seven limbs and nineteen mouths.”

The sound U (pronounced “oo”) is the middle sound, rolling forward from the back of the mouth to the lips. It represents the dreaming state (Svapna), where consciousness is turned inward, creating its own objects from the impressions of the waking state.

Characteristics of the dreaming state:

• Creates an internal world of images, sounds, and emotions
• The dream seems real while dreaming
• The dreamer is not aware they are dreaming
• Upon waking, the dream is seen as unreal

How to experience the “U” of OM: When you chant OM, feel the “U” as the continuation, the inward turn, the dreaming mind creating its own reality. It is like the dream world — vivid, real while it lasts, but known to be unreal upon waking.

Third Part: M — Deep Sleep State (Prajna)

The Upanishad says:

“The third quarter is Prajna (the state of deep sleep). Its sphere is the state of deep sleep. It is a mass of consciousness, made of bliss, and the door to the knowledge of the other two states.”

The sound M (pronounced “mmm”) is the final sound, closing at the lips. It represents the deep sleep state (Sushupti), where there are no objects — neither external nor internal. The mind is completely still. There is no perception, no desire, no fear, no suffering.

Characteristics of deep sleep:

• No external objects (waking state is absent)
• No internal objects (dreaming state is absent)
• A state of blissful peace, but also of ignorance
• You wake up and say, “I slept well. I knew nothing.”

How to experience the “M” of OM: When you chant OM, feel the “M” as the closing, the dissolution, the return to unity. It is like deep sleep — peaceful, blissful, but without awareness of the Self.

Fourth Part: Silence — The Fourth State (Turiya)

The Upanishad says:

“They consider Turiya to be that which is not conscious of the internal world, nor conscious of the external world, nor conscious of both, nor a mass of consciousness, nor consciousness, nor unconsciousness. It is unseen, beyond transaction, ungraspable, without distinguishing marks, unthinkable, indescribable. The essence of the knowledge of the one Self, the cessation of all phenomena, peaceful, blissful, non-dual. This is the Atman. This is to be realized.”

The silence after M is not the absence of OM. It is the ground of OM. Just as the silence between two notes is not empty but full of potential, the silence after OM is the fullness of consciousness itself. This is the fourth state — Turiya — which is not a state like waking, dreaming, or deep sleep. It is the reality that underlies, pervades, and transcends all three states.

Characteristics of Turiya:

• Not aware of external objects (unlike waking)
• Not aware of internal objects (unlike dreaming)
• Not a mass of consciousness (unlike deep sleep)
• Not unconsciousness
• Unseen, ungraspable, unthinkable, indescribable
• Peaceful, blissful, non-dual

How to experience the silence of OM: After chanting OM, rest in the silence that follows. Do not try to “do” anything. Do not expect anything. Simply rest as the aware presence that is already there. That silence — not empty, but full of awareness — is Turiya. It is the Self. It is Brahman.

The Four Parts of OM and the Four Mahavakyas

The four parts of OM also correspond to the four Mahavakyas (Great Sayings) of the Upanishads:

Part of OM	State	Mahavakya	Meaning
A	Waking	Prajnanam Brahma	Consciousness is Brahman
U	Dreaming	Tat Tvam Asi	That you are
M	Deep Sleep	Aham Brahmasmi	I am Brahman
Silence	Turiya	Ayam Atma Brahma	This Self is Brahman

When you chant OM and meditate on its four parts, you are meditating on the entire scope of Vedantic philosophy.

How to Meditate on OM (The Method of the Mandukya Upanishad)

The Mandukya Upanishad does not just explain OM theoretically. It prescribes meditation on OM as a direct path to Self-realization.

Step-by-step practice:

Step 1: Sit comfortably. Close your eyes. Take a few deep breaths.

Step 2: Chant OM aloud three times. Feel the vibration in your body.

Step 3: Begin to chant OM silently in your mind. Feel each part:

• A (ah): Feel the waking state. Be aware of the external world. Then let it go.
• U (oo): Feel the dreaming state. Be aware of internal thoughts and images. Then let it go.
• M (mmm): Feel the deep sleep state. Let all objects dissolve. Rest in blissful peace.

Step 4: After M fades, rest in the silence that follows. Do not try to “do” anything. Do not expect anything. Simply rest as the aware presence that is already there.

Step 5: Recognize: This silence is not empty. It is full of consciousness. It is not separate from you. It is what you are. This is Turiya. This is Atman. This is Brahman.

Step 6: Remain in this silence for as long as comfortable. When thoughts arise, gently return to the silence.

The promise of the Upanishad: “One who knows OM as the Self (Atman) attains the Self. Such a one enters the Self, attains the Self, becomes the Self.”

OM and the Three States of Consciousness: A Summary Table

Aspect	Waking (Jagrat)	Dreaming (Svapna)	Deep Sleep (Sushupti)	Fourth (Turiya)
OM Part	A	U	M	Silence
Name	Vaishvanara	Taijasa	Prajna	Atman
Objects	External	Internal	None	None
Awareness	Of objects	Of mental images	No objects	Of itself
Identification	With body	With dream body	With nothing	With nothing (pure witness)
Reality	Appears real	Appears real	Not aware	Real

Common Misunderstandings About OM

Misunderstanding 1: OM is just a sound, like any other sound.
Correction: OM is not an ordinary sound. It is the primordial sound — the vibration from which the entire universe emerges. All other sounds are manifestations of OM.

Misunderstanding 2: You should only focus on the sound, not the silence.
Correction: The silence after M is the most important part. The sound of OM is the path. The silence is the destination.

Misunderstanding 3: OM is a symbol for Brahman, not Brahman itself.
Correction: The Mandukya Upanishad says OM is Brahman, not just a symbol for Brahman. The syllable and the reality are identical for the realized person.

Misunderstanding 4: Repeating OM mechanically leads to liberation.
Correction: Repetition without understanding is mechanical. The Upanishad teaches meditation on OM — understanding its four parts and their correspondence to the four states of consciousness.

The Promise of the Mandukya Upanishad

The Mandukya Upanishad ends with a promise:

“OM is this whole universe. This is the Atman. This is Brahman. One who knows this enters the Self, attains the Self, becomes the Self.”

This is not a promise for after death. It is a promise for here and now. Liberation is not a future event. It is the recognition of what has always been true. And OM is the key.

Conclusion: The Sound of Silence

According to the Mandukya Upanishad, OM is not merely a mantra. It is the very fabric of reality. The three sounds — A, U, M — correspond to the three states of consciousness: waking, dreaming, and deep sleep. The silence after M corresponds to the fourth state — Turiya — pure, non-dual, blissful consciousness, which is the Self (Atman) and Brahman.

To meditate on OM is to meditate on the entire universe. To know OM is to know the Self. To realize OM is to be free.

Chant OM. Feel the “A” of waking, the “U” of dreaming, the “M” of deep sleep. Then rest in the silence. That silence is not empty. It is full of you. It is full of consciousness. It is full of peace. It is full of freedom. It is what you are.

As the Mandukya Upanishad declares:

“OM is this whole universe. This is the Atman. This is Brahman. One who knows this enters the Self, attains the Self, becomes the Self.”

Om Shanti Shanti Shanti.