Just as the mantra is the first stir of creation or manifestation, a yantra is a form that represents the Deity who is being evoked. The figure is a symbolic representation. The tantric yogis have over centuries discovered, formulated and fixed certain figures or geometrical patterns through centuries of practice to invoke the Deities concerned. The diagram and the formula have its value but of much more value is the faith that the devotee puts in the practice. The deities have access to the heart of the devotee and know his intent even if he tries to hide it, sometimes even from himself! They respond to this hidden intent, this faith, this genuine aspiration, the sincerity of the prayer rather than the mechanical formulas which can hardly entice beings of the higher worlds who are far more conscious than we are.
What we need to understand is that all these are symbols. They are the mind’s ways of perceiving and receiving the Infinite who is beyond all symbols, sounds and patterns. Yet they help us in the opening to that which is Beyond. But the same things can be done, even much more effectively, since it something living rather than mechanical and rule-bound by a sincere and intense aspiration, with or without words, a deep longing, a true need of the Divine in our life. The Divine is not bound by any formula since He is Freedom Itself and if He seems to respond to these practices it is simply as a concession to our limited beliefs and the means that we trust will connect us to Him. But in Truth, He hears even the mute prayer of the bird and the beast, the wordless hymn of the plants, and responds even to the dumbness of the mountains and the stones. Sri Aurobindo reveals to us some of these truths in His evening talks:
“Sri Aurobindo: There are people who say “cow” should not mean “Light”. But what can “herds of the Sun” mean? It can only mean “Rays of solar light”. There are certain life-symbols: e.g. “Mountain” stands for “ascent”, going high up. “Bridge” or “crossing of rivers” is also a symbol from life-surroundings.
Then there are certain symbols that have an inherent appositeness of their own: for instance, Akasha – sky stands for the Eternal Brahman. In any nationality or any culture, “Sky” always indicates the Infinite. “Sun” always stands for the Supramental Light – it is the Sun of knowledge.
Then there are mental symbols; once fixed they become active on their own plane, e.g. “OM”, – Numbers, alphabets, geometrical figures – these have their own interpretations, e.g., the square always indicates to me the Supermind: it is a perfect shape.
Disciple: How did you know that the square is the symbol of the Supermind?
Sri Aurobindo: It might have been already found on the mental plane by somebody or might have come into my mind by some force. I did not pursue its meaning; it indicated to me the Supermind and I was satisfied.
The triangle indicates the world formed by the three lower powers. Another triangle placed with, its apex opposite indicates the three higher plane of being. When the two triangles are superimposed upon each other then a new symbol is found. The ancients indulged in these speculations.
It is also possible that the same reality may seek expression through different symbols, and if you go behind you find it is the same thing which is Infinite and unlimited by the symbol.
Disciple: What do you think of the Tantric sounds “Hring” “Kling” etc. ?
Sri Aurobindo: They are not mere sound, there must be some force behind them. The same is true about Mantra Siddhi : three states are represented by “OM” and they can act differently in different men.
Disciple: The numbers being universal, why can’t they be universal symbols ?
Sri Aurobindo: They are absolute to the human mind only; they are essential for our way of perceiving. There may be another plane of consciousness where they may not be so absolute, and where “one” may be at the same time “two”. Numbers are the way of perceiving certain unalterable facts on the physical plane. It means that the mind can cut up the Infinite, take one and one and one and then say about each: “this is one”. Physically, there are certain unalterable laws, e.g., going through the door is not possible without opening it, but the contrary of it may exist elsewhere.”
[A.B. Purani, Evening Talks with Sri Aurobindo, 4 June 1926]