Let us examine how words arise. By the time words reach the tip of the tongue, they have taken a gross form. However, before they make their way to the tongue, they have passed through all the levels of speech. The subtlest level of speech is paravani. This is the region of pure, un-manifest sound, where there is neither duality nor non-duality. Paravani is actually all-pervasive. It is the subtle vibration from which the entire universe, with all its forms, is born. Here all sounds, all worlds, and all languages arise from pure Consciousness.

Just as a peacock egg contains all the colors of a peacock's feathers in a potential form, all syllables and words exist within paravani in an undifferentiated seed form. As sound arises, it passes to the third level of speech, pashyanti. At this level, through the work of the Matrika Shakti, it begins the process of assuming form, but it is not yet in a completely differentiated state.

When sound passes from this level to the madhyama level of speech in the throat, it assumes a recognizable form. It is at this point that words begin to create the world of differences inside us. Here words are fully formed, although they have not yet been uttered. Finally, they pass to the gross tongue, the vaikhari level of speech, where they are articulated and can be heard.

The Mantra has the power to penetrate through these gross and subtle levels of sound, erasing our sense of difference and carrying us back to its source. When we repeat it, it passes from the gross to the subtler levels, until it reaches the pure Consciousness from which it has arisen.

In the initial stage, we repeat the mantra silently on the level of the tongue, listening to the mantra as we repeat it and focusing the mind on the tip of the tongue, where the mantra is vibrating. After we have repeated the mantra on this level of speech for while, it goes deeper, to the madhyama level in the throat. One repetition at this level is equal to thousands of repetitions with the physical tongue.

From the throat center the mantra descends to the pashyanti level in the heart, where its vibrations become even more powerful. One repetition in this center is equal to thousands of repetitions in the throat center. When mantra repetition is taking place at the pashyanti level, we feel wave upon wave of bliss and we acquire unusual powers; we are able to see and hear what is distant and to know the past and the future. Now the repetition of the mantra goes on continually, and we remain in an intoxicated state.

Finally the mantra passes from the heart center to the navel center, the paravani level of speech, where it touches the Self. Then the entire body becomes permeated by the mantra, and we experience the supreme Truth. This is how the power of the mantra is realized.

Once a being has realized the potency of the mantra, once he has made it touch the Self, the power of the Self pervades his words and makes them unfailing in their effect. That is why the mantras of Siddha yogis inevitably bear fruit. One who has fully realized the mantra obtains all the powers of the Self. Any word that comes from his mouth comes from paravani, the space of Consciousness. For this reason, every word he utters is a mantra and will always do its work.

In Siddha Yoga, we give two mantras: one is the initiation mantra, Om Namah Shivaya, and the other is So'ham. The goal of both mantras is the same; only the method of repeating them differs.

Om Namah Shivaya is known as the great redeeming mantra and as panchakshari, the five-syllable mantra. It means, "I bow to Shiva." Shiva is the supreme reality, the inner Self, Shiva is the Consciousness that dwells in all.

The mantra that the Guru imparts to a seeker is the mantra he received from his own Guru. This is known traditionally as the Guru mantra or initiation mantra. Om Namah Shivaya is the initiation mantra of the Siddhas, the lineage of perfected Masters which traces its origin back to Shiva, the primordial Guru.