The easiest way to understand is as follows:
- An Arahant has six indriya or ‘sensory faculties’: cakkhu indriya, sota indriya, jivhā indriya, ghāna indriya, kāya indriya, and mano indriya. Arahants can experience the world (like anyone else) without the arising of any defilements (rāga, dosa, moha) by using those six indriya.
- A puthujjana (average human) has six āyatana or ‘defiled sensory faculties’: cakkhu āyatana, sota āyatana, jivhā āyatana, ghāna āyatana, kāya āyatana, and mano āyatana. They ALWAYS experience the world WITH defilements (rāga, dosa, or moha) using those six āyatana.
- In the suttās, these six āyatana are, in many cases, abbreviated as just cakkhu, sota, jivhā, ghāna, kāya, and mano (without specifically saying they are āyatana). Sometimes they are stated specifically, e.g., cakkāyatana or cakkhu āyatana.
- Therefore, it is incorrect to translate “mano” as mind (as done in Sutta Central and many other websites). Mano, in most cases, refers to the defiled mind of a puthujjana, i.e., it is manāyatana or mana āyatana.
- When a puthujjnana attains Arahanthood, the six āyatana automatically convert to six indriya.
__
Question: “Is it the logical portion of the mind and or does it also include thoughts of visual forms (Rupa) and forms related to the other senses?”
- All six sensory faculties experience the world with the mana indriya/āyatana.
- The other five (cakkhu, sota, jivhā, ghāna, kāya) are only “doors” to the outside world.
- For example, the cakkhu indriya/āyatana helps to see, i.e., the “rupa” or sight comes in through the cakkhu, but is experienced by the mind. The mind cannot directly receive rupa, sadda, gandha, rasa, or pottabbha.