From some time I have been thinking of the best way to distil the meaning of Luang Poo Tate’s (and the Thai teachers in general) explanation of the mind and what happens to it through meditation. I hope the following does him justice. If not, that is my fault.
The Citta is like plasticine or playdough. A single ball of plasticine can be moulded into many things, a figurine, a house, an aeroplane, a car, all sorts of things. The Citta is moulded into the Nama Khandha. However, just as the plasticine objects are not the plasticine itself, merely expressions of the plasticine, so too the Khandha are but expressions of the Citta.
Through the power of Samadhi, the Khandha can be reduced back to a singularity (a single ball of plasticine). This singularity is, Citta Ekaggata. At this point, the singularity (the ball of plasticine) still contains contaminants; Avijja, Tanha, Kilesa. These contaminants don’t alter the molecular structure of the plasticine, but they do eventually cause the singularity to breakup, at which time the Khandha are re-expressed.
Through the combined power of Samadhi and Panna more subtle types of singularity are able to be formed. These are the singularities that define the stages of Ariya. They are the Magga moments that occur when the Ariya experience the path factors converge on Sammaditthi. The difference between these singularities and that reached by Samadhi alone is that, at each stage of Ariya, some contaminants are expelled from the plasticine (Citta).
When the final singularity happens (Arahant), all contaminants are expelled. However, the unique molecular structure of the plasticine remains unchanged – just as the pure nature of the Citta is unchanged. This uniqueness, by definition, is itself a new singularity. This unchanged, unique nature is Asankhata. Nibbana. Only past Kamma causes little lumps of plasticine to remain but all attachment to these lumps has been destroyed.
This unique singularity, Nibbana, is different to the Samadhi/Panna singularities because they were all Sammuti. They occurred because of conditions, Sila, Samadhi and Panna. The uniqueness of Nibbana is Asankhata. It is beyond conditioning. It is and always will be deathless, void and signless.