I am glad to hear that Jorg’s and Dosakkhayo’s concerns/questions have been resolved.
Jorg wrote: “The mana indriya is located in the brain. The hadaya vatthu is located in the heart region. In one part, Lal mentioned that the mana indriya becomes manaytana and in another part that the hadaya vatthu becomes manayata.”
The Tipitaka is not very clear about what is defiled by cakkhu, sota, ghana, jivha, kaya, and mana indriya.
That is why I wrote in my previous comment explaining the cakkhu indriya as follows: “Cakkhu indriya can be thought of as the whole system comprising the physical eyes, nerves connecting to the visual cortex in the brain, the visual cortex, and the cakkhu pasada rupa. If any of those do not function, no signal will reach the hadaya vatthu, i.e., there will be no vision. An Arahant or an average human can see unless blind.”
- That could be a better way to explain the cakkhu indriya (and the others similarly.)
Therefore, mana indriya could be considered to incorporate any brain functions as well as the hadaya vatthu.
- Of course, hadaya vatthu is where the cittas arise. That would not change.
- But just as an average human uses the cakkhu indriya as cakkhayatana, the mana indriya (the system comprising the hadaya vatthu and brain functions) is used as manayatana.
Therefore, I think the above description could be better. (The Pali word for the physical eye is “nayana,” but I have not seen it used to defile the cakkhu indriya. The reason could be that the role of the brain was completely unknown to humans at the time of the Buddha. He could not have explained it to people at that time.)
Of course, the following is what matters:
- Cakkhu indriya enables us to see. Sota indriya enables us to hear….Mana indriya enables us to think.
- Each indriya is used as the respective āyatana by an average human.
- An Arahant does not have āyatana but has the respective indriya.
