C.Saket said: “wonder why beings in the realms 28-31 are called “arupavacara” brahma ? and why these realms are called “arupa” loka ? (since arupavacara brahmas have hadaya vatthu which is technically a rupa)”.
Arupavacara was a word introduced by ancient yogis and had been in usage when the Buddha was born. Rupa above the suddhshtaka stage start at bhuta stage, where it is just a suddhashtaka. The next more condensed state is “maha bhuta” with large aggregates of suddhashtaka, and then even more condensed statges of “dhathu”. See:
The Origin of Matter – Suddhāshtaka
Higher the one’s realm is finer rupas one can see. We can see only highly condensed “dhatu”. Devas have much finer bodies and can see finer “dhatu”. Rupavacara brahmas can see “maha bhuta”. A given being can see one’s own level and lower levels.
However, arupavacra brahmas cannot see rupa above the suddhashtaka stage because they do not have cakkhu (or sota) pasada rupa. They have only a hadaya vatthu and thus can only access “dhamma below the suddhashtaka stage” via “mananca paticca dhammeca uppadati mano vinnanam”.
Therefore, there are no rupa above the suddhashtaka stage in arupavacara realms, AND the only rupa at the suddhashtaka stage are only the hadaya vatthus of those brahmas. Thus, when ancient yogis attained arupavacara jhanas, they did not see any rupa there, So, those yogis gave the name “arupavacara” to those realms.
Therefore, any rupa above the suddhashtaka cannot be seen by an arupavacara brahma, because they don’t have cakkhu indriya. A suddhashtaka cannot be seen by rupavacara brahmas, because they can see only “maha buta” or large aggregates of suddhashtaka. Only a Buddha can see a suddhashtaka.
Sybe07 said: “Lal, when the mind becomes free of asava’s does it become free of seeing, hearing, feeling, tasting etc? Would that really be the case then an arahant, who’s asava’s have ended, cannot live this life anymore. Attaining Nibbana would make live impossible if this would mean that mind would end too….”
When a living being is in a given bhava in the kama loka (human, animal, deva, peta, etc), its sense faculties experience likes/dislikes based on that bhava, and these are called “kama guna”. Some kama guna can be matching, but others are different from bhava to bhava. Humans and dogs enjoy some similar foods, but dogs also eat feces. A human (with some exceptions based on kamma vipaka), taste saltiness of salt and sweetness of sugar. That holds for even an Arahant until the Arahant attains Parinibbana, i.e., passes away, see:
Kāma Guna, Kāma, Kāma Rāga, Kāmaccanda
There are two types of Nibbana: saupadisesa Nibbana and anupadisesa Nibbana:
See “Nirödha and Vaya – Two Different Concepts”.
All sense faculties keep functioning after one attains the Arahant stage; kama guna do not change since an Arahant is still in human bhava. An Arahant only loses any craving for them. Any thought generation stops at anupadisesa Nibbana.
We can look at this from another angle to make this clear.
A living being moves to higher realms by seeing the adinava (unfruitfulness/dangers) in sense pleasures at lower realms.
In the realms of kama loka, beings enjoy sense pleasures through all five physical senses.
In the rupavacara brahma loka, smell, taste, and touch are not there. One gets born in such realms when one develops rupavacara jhana and regularly cultivates them in the human realm; one has lost craving for sense pleasures through the tongue, nose, and the body (but anusaya remains, so those cravings can come back in future lives). In rupavacara brahma realms one enjoys only seeing and hearing.
Even those sense pleasures experienced with seeing and hearing are of not value to those who have cultivated arupavacara jhana; But they have not given up the desire to live (bhava raga). That cannot be removed without comprehending the real nature of all 31 realms: anicca, dukkha, anatta.
Only a Buddha can figure out how to remove Bhava raga. So, a Buddha finds the way to be free from all 31 realms.