You may do any posture, but I allow these postures only when they come by themselves. Someone can sit down and be silent in siddhasan or in any other posture, but this siddhasan is something quite different; the quality differs. He is trying to be silent in sitting – but this is a happening, there is no suppression, there is no effort; it is just how your body feels. Your total being feels to sit. In this sitting there is no divided mind, no suppression. This sitting becomes a flowering.
You must have seen statues of Buddha sitting on a flower, a lotus flower. The lotus is just symbolic; it is symbolic of what is happening inside Buddha. When “just sitting” happens from the inside, you feel just like the opening of a flower. Nothing is being suppressed from the outside; rather, there is a growth, an opening from the inside; something inside opens and flowers. You can imitate Buddha’s posture, but you cannot imitate the flower. You can sit completely buddhalike – even more buddhalike than Buddha – but the inside flowering will not be there. It cannot be imitated.
You can use tricks. You can use breathing rhythms that can force you to be still, to suppress your mind. Breath can be used very suppressively because with every rhythm of breath a particular mood arises in your mind. Not that other moods disappear; they just go into hiding.
You can force anything on yourself. If you want to be angry, just breathe the rhythm that happens in anger. Actors do it, when they want to express anger they change their breathing rhythm; the breathing rhythm must become the same as when there is anger. By making the rhythm fast they begin to feel anger, the anger part of the mind comes up.
So breathing rhythm can be used to suppress the mind, to suppress anything in the mind. But it is not good, it is not a flowering. The other way is better; when your mind changes and then, as a consequence, your breath changes; the change comes first from the mind.
So I use breathing rhythm as a sign. A person who remains at ease with himself constantly remains in the same breathing rhythm; it never changes because of the mind. It will change because of the body – if you are running it will change – but it never changes because of the mind.
So tantra has used many, many breathing rhythms as secret keys. They even allow sexual intercourse as a meditation, but they allow it only when your breathing rhythm remains constant in intercourse, otherwise not. If the mind is involved, then the breathing rhythm cannot remain the same, and if the breathing rhythm remains the same, the mind is not involved at all. If the mind is not involved even in such a deep biological thing as sexual intercourse, then the mind will not be involved in anything else.