The Pranava Om is the bija of all mantras. Within a seed (bija) is the potentiality of manifestation, and Om was the sound of the initial spandana (vibration) out of which the whole cosmos was manifested. Om, therefore, can be considered as the/symbol of total creativity and it is also said to be the creator, for in Hindu philosophy, the creator and the creation are inseparable. This is what is meant by the declaration in the Rig Veda (the oldest Veda, where the word Om was first mentioned) that Om is the symbol of the cosmos. The whole cosmos is time, space and matter, and the first verse of the Mandukya Upanishad, which is a small Upanishad dealing with the significance of Om, says:
"The past, the present and the future, everything, is just Om. And whatever else transcends the three divisions of time that too is only the syllable Om."
The Mandukya, although consisting only of twelve verses, is in itself a complete treatise on Om. It relates the individual matras or component sounds A, U and M with the entire range of human consciousness, beginning from the waking state and ending with the supreme, absolute state of sub-consciousness (turiya) where all objective, relations and perceptions of duality are completely negated.
Turiya is not a 'state' like the others, since it is present in all the states and is actually the whole of reality, pure consciousness in itself.
The Mandukya is also an exposition of the Pranava as a complete symbol of the atman in its pure as well as relative aspects. Verse 8 says that the atman, when considered (or meditated on) in a general way, is to be identified with Om (the vedic name of the atman) taken as a single syllable (that is, without analysis into its matras - A, U and M). When Om is considered as composed of parts, the quarters (states of consciousness) of the atman are to be identified with the parts A, U and M. (This latter gives a more thoroughgoing meditation when Om is analyzed into its constituent sound elements or parts.)
|The entire range of human consciousness begins with the waking state and ends with the absolute state of super-consciousness, where all objective relations and perceptions of duality are completely negated.|
|State of consciousness||Microcosmic or individual||Microcosmic or individual|
|Waking state (Jagrat)||Vishva Physical 'A' of Om||Virat (Cosmic manifestation)|
|Dream state (Swapna)||Taijasa Mental 'U' of Om||Hiranyagarbha (Universal mind)|
|Sleep state (Sushupti||Prajna Intellectual 'M' of Om||Ishwara (First cause or God)|
|Superconscious state (Turiya)||The transcendental that runs through all the states and forms the basis of the sense of self-identity felt with regard to the changing states. Though called the fourth, it is really the whole, being the Brahman-atman. Soundless aspect of Om.|
'A' is associated with the waking state because it is "both all pervasive and has a beginning" (v.9). From the waking state all knowledge of other states comes, and so it may be said to pervade them, and it has a beginning in that it precedes both dream and sleep states. Likewise, 'A', being the first letter, begins the alphabet and it is all pervasive because it is included in all other sounds. No sound can be produced without opening the mouth, and the first sound produced on opening the mouth is 'A'.
'U' is associated with the dream state, and as dream is between waking and deep sleep so 'U' is between 'A' and 'M'.
Waking and dream both merge into sleep and so also the 'A' and 'U' merge into the 'M', symbolizing the merging into oneself. This state is identified with Ishwara, the Lord of all; for just as Ishwara is the creator of the whole universe, from the consciousness in deep sleep springs all the phenomena of waking and dream states.
The final verse of the Mandukya reads:
"The syllable Om in its partless (i.e. soundless) aspect is the fourth state (turiya)- transcendental, devoid of phenomenal existence, supremely blissful and non-dual. Thus the syllable Om is verily the Self (atman). He who knows this, merges his self in the Self."
In both deep sleep and transcendental consciousness there is no consciousness of objects. But this objective consciousness is present in an un-manifested seed form in deep sleep while it is completely transcended in turiya. Thus in turiya, the mind is not simply withdrawn from objects but becomes one with Brahman.
'Om in its partless aspect' can be interpreted in different ways. It can be taken as meaning that "the syllableless or soundless Om is what is inherent in Om as a manifested sound, just as turiya is inherent in all the states. It is the un-manifested and transcendent sound of which all manifested sounds, including Om, are expressions. Hence the appropriateness of identifying it with turiya." This is the significance Swami Sarvananda gives it.
On the other hand one can relate the Om composed of parts, i.e. AUM, more closely to the physical manifestation of it in the body. 'A', the first sound, is produced as a pure, open column of air rising from the abdomen and issuing unobstructed through the mouth. 'U' raises the sound to the back of the throat, while the nasalized 'M', intoned with lips closed, carries the vibrations upwards and inwards to stimulate sahasrara chakra. The state of turiya is then experienced after the physical sound is terminated, but before the next inhalation, in that period of suspension of the breath. In this way the chanting of long, drawn out 'A - U - M' with concentration on the source of each sound element can carry one through the different states of consciousness into the silence of the final kumbhaka.
It is said that all mantras can be produced from AUM. Using the foregoing analysis of the physical production of the sound elements, this can be easily explained on the physical level. Between the initial 'A' and the final, closed 'M', the air passes unimpeded through the throat and mouth. By manipulation of vocal cords, tongue, teeth and lips to change this clear flow of the breath, every possible letter can be spoken.