The Four Formless Realms are states which are experienced temporarily in meditation. They lie beyond the Four Dhyanas (see entry), and are so subtle, they are difficult to talk about using ordinary language and even defficult to conceptualize.
They also correspond to the four formless heavens, the homes of the formless Gods (see Gods). In other words the states can be experienced for a relatively short time by humans who have reached them in the course of their meditation, or they can be experienced as states of rebirth for those reborn as Gods in the formless heavens.
Those who Dwell in the thought of re[[nunciation]] and who succeed in re[[nunciation]] and rejection realize that their bodies are an obstacle. If they thereby obliterate the obstacle and enter empty space, they are among those in the realm of (Infinite) space. (SS VII]] 230-231)
“These Gods accomplish re[[nunciation]] of bliss and rejection of suffering (Dukkha). They know that physical bodies are an [[obstruction]]. . . . They don't want to be hindered by anything, and so they contemplate their bodies as being just like empty space. . . .” (SS VII]] 231)
For those who have eradicated all obstacles, there is neither [[obstruction]] nor extinction. Then there remains only the alaya consciousness (i.e., eighth consciousness) and half of the subtle functions of the Manas (i.e., seventh consciousness). these beings are among those in the realm of Infinite consciousness.“ (SS VII]] 231)
At this stage one abandons empty space as an object and also abandons the feelings, cognitions, formations, and consciousness that are associated with it. The only attachment that remains is to a consciousness that is immense and Infinite.
III. nothing Whatsoever
Those who have already done away with empty space and form eradicate the conscious mind as well. In the extensive Tranquility of the ten directions there is nowhere to go at all. These beings are among those in the realm of nothing whatsoever. (SS VII]] 232)
“All the worlds of the ten directions throughout the entire Dharma Realm have disappeared. A Stillness pervades. There is nowhere to go. Nor is there anywhere to come to. . . . Although there is nothing whatsoever; nonetheless, the nature of these beings still remains. Their nature is the same as empty space.” (SS VII]] 233)
When the nature of consciousness does not move, within Cessation (Nirodha) they exhaustively investigate. Within the endless they discern the end of the nature. It is as if it were there and yet not there, as if it were ended and yet not ended. They are among those in the realm of neither cognition nor non-cognition. (SS VII]] 233-234)
”consciousness is practically non-existent, and so it is said that there is no thought. However, a very fine trace of thought still exists and so it is called neither cognition nor non-cognition.“ (SPV 60)
1) Chinese: sz kung chu , sz wu sz/shai jye , sz wu sz/shai ding (chu) ; 2) Sanskrit: arupya-Sama]]patti, arupya-Dhatu; 3) Pali aruppa-Sama]]patti/Dhatu; 4) Alternate translations: stations of emptiness, formless Samadhis, Sama]]pattis, formless absorptions.