The Buddhist universe consists of thirty-one planes of existence
Four planes of the Immaterial Brahma Realm:
(31) Plane of Neither Perception-nor-non-Perception
(30) Plane of Nothingness
(29) Plane of Infinite Consciousness
(28) Plane of Infinite Space
Sixteen planes of the Fine Material Brahma Realm:
7 Fourth Jhana Planes:
5 Pure Abodes:
(27) Highest (Akanittha)
(26) Clear Sighted (Sudassi)
(25) Beautiful (Sudassa)
(24) Serene (Atappa)
(23) Durable (Aviha)
(22) Non-percipient, matter only, no mind
(21) Great Fruit
3 Third Jhana Planes:
(20) Third Jhana, highest degree
(19) Third Jhana, medium degree
(18) Third Jhana, minor degree
3 Second Jhana Planes:
(17) Second Jhana, highest degree (Abhassara)
(16) Second Jhana, medium degree
(15) Second Jhana, minor degree
3 First Jhana Planes:
(14) First Jhana, Maha Brahmas
(13) First Jhana, Brahma's ministers
(12) First Jhana, Brahma's retinue
Eleven planes of the Sensuous Realm :
Seven Happy Sensuous Planes:
Six Deva planes:
(11) Control others' creations
(10) Rejoice in their own creations
(2) Animal realm
(1) Hell realms
The lowest area (planes 1-11) is called the sensuous realm; here sense experience predominates. Next comes the fine-material realm (12-27) attained by practicing the fine-material absorptions (rupa-jhanas). Above that is the immaterial realm (28-31) attained by practicing the immaterial absorptions (arupa-jhanas).
Although humans appear to be rather low on the scale, many intelligent deities long for rebirth on the human plane. Why? Because the best opportunity to practice the Dhamma and attain liberation is right here on earth. On the lower four planes, little progress can be made as suffering is gross and unrelenting and the opportunity to perform deeds of merit is rarely gained. The very bliss of the higher planes beclouds the universal characteristics of all phenomena: impermanence, unsatisfactoriness, and the lack of any lasting, controlling self. And without fully comprehending these principles, there is no motivation to develop the detachment from the world that is essential to liberation.
Before examining the chart in detail, a few notes on terminology are in order. We will use the word "deva" to include deva, devata, and devaputta referred to in the Suttas, as all three terms are almost synonymous. Although "deva" is often used in the Pali texts to refer to all super-human beings, "deva" and "brahma" can generally be distinguished. "Deva" in its more limited sense refers to beings in the six planes immediately above the human one (6-11), the sensuous heavens. When "deva" refers specifically to these sense-sphere beings, the term "brahma" is used for those residing in the fine-material planes (12-27) and immaterial planes (28-31). If in a particular discourse "deva" is used for a being who clearly fits into the category of brahmas (as sometimes happens), we will call him a brahma; if the deva is actually a sense-sphere being (or if his identity is unclear) we will retain "deva." For variety, we occasionally use "deity" and "god" as translations for deva in all its senses.
Let us now study some features of the chart. The lower beings and humans do not have fixed lifespans, but higher beings do. As you go up the chart from the sixth plane to the thirty-first, each successive group of deities lives longer than the group below it. The lifespans of devas are measured in multiple centuries. The duration of a brahma's existence can only be expressed in aeons. The Buddha defines these extremely long periods of time by analogy. An aeon is the length of time it would take to wear away a mountain of solid rock six miles high and six miles wide, rubbing over it with a fine piece of muslin once every hundred years. The highest brahmas of the immaterial sphere live for 84,000 aeons.
All beings — human, sub-human, devas, and brahmas — die. All except arahants are reborn in one or another of the thirty-one planes. No being lasts forever. Arahants have eradicated all mental defilements and have thereby eliminated the causes for rebirth with its attendant suffering. They are not reborn after death. Instead, they attain Parinibbana, the complete, permanent cessation of every form of existence. For all non-arahants, death is immediately followed by rebirth. The plane of birth is determined by the kamma that becomes operative at the moment of death. This could be any volition created in the present life or in any previous existence. Even the three lower kinds of noble ones (ariya) must be reborn. They have effaced some of the mental defilements, are assured of eventually attaining Nibbana, and will never again be reborn in the lower planes. Noble ones of the two lower kinds — stream-enterers and once-returners — can be reborn in the deva planes. For anyone who is not an ariya — and this includes most devas and brahmas — the destination of rebirth is uncertain. It may be on the same plane or on a higher one; but most often it is on a lower plane. Rebirth is neither arbitrary nor controlled by a God. It takes place strictly due to kamma, the deeds we have performed and continue to perform all our lives. Brahmas too die and are reborn, and also suffer, even though their lives are so extremely long that they may be deluded into believing they are permanent.
The devas of the sensuous sphere are said to enjoy sense pleasures in far greater abundance than can be found in the human world. Their bodies emit light and they have subtle sense organs, similar to ours but far more powerful and acute. That is why the supernormal powers of seeing various realms and hearing at great distances are referred to as deva vision and deva hearing. On the deva planes there are stream-enterers and once-returners. For example, Sakka, king of the gods in the heaven of the Thirty-three, became a stream-enterer while discussing the Dhamma with the Buddha, as we will see below. However, only few among the devas have any understanding of the Dhamma. In fact, all that is needed to be reborn in these heavens is the meritorious kamma of generosity and good morality. Mental development through meditation is not a prerequisite for rebirth on the higher sensuous planes.
The fine-material brahmas have extremely subtle bodies of light; their powers are great but not unlimited. A being is reborn among these brahmas by cultivating the appropriate jhana, perfecting it, and retaining it at the moment of death. Jhanas are states of deep concentration that can be attained by unifying the mind through meditation. They are all wholesome states of a very lofty and sublime nature. But one can get "stuck internally" in any of the jhanas and thereby block one's progress towards awakening. There are four fine-material jhanas. The beings in the brahma planes spend most of their time enjoying their respective jhanas. Brahmas experience no ill will or hatred, but only because they have suppressed it by their jhana, not because they have uprooted it from their mental continuum. Thus when a brahma is eventually reborn as a deva or human being he or she can again be beset by hatred. (After one birth as a deva or human, a former brahma can even fall to one of the lower planes of the grossest suffering.) The brahmas also are prone to conceit and belief in a permanent self, as well as to attachment to the bliss of meditation. Fine-material brahmas can interact with the human plane if they so choose, but to appear to humans they must, like the devas, deliberately assume a grosser form. Later we will meet a number of brahmas who converse with the Buddha.
The immaterial brahmas of the four highest planes have no material bodies whatsoever. They consist entirely of mind. They attained this kind of birth by achieving and maintaining the immaterial jhanas, four kinds of absorption taking non-material objects, and it is this kamma that became operative at their death. These brahmas can have no contact with the human or deva planes, for they have no physical bodies; thus we will rarely mention them. They spend countless aeons in the perfect equanimity of meditation until their lifespan ends. Then they are reborn in the same plane, a higher immaterial plane, or as devas. After that they too can be reborn on any plane at all. So even existence without a body is not the way to permanently eliminate suffering.
Only practicing the Noble Eightfold Path can bring suffering to an end. In fact, immaterial brahmas are in the unfortunate position of being unable to start on the path. This is because one has to learn the Dhamma from the Buddha or one of his disciples to attain the first stage of awakening, to become a stream-enterer. That is why the sage Asita, called by the Buddha's father to examine the newborn Bodhisatta, wept after predicting that Prince Siddhattha would become a Buddha. The sage knew he was going to die before the prince attained Buddhahood. He had cultivated these immaterial absorptions so he would have to be reborn in the immaterial realm and would thereby lose all contact with the human plane. This meant he would not be able to escape samsara under Gotama Buddha. He was sorely distressed to realize that he would miss this rare opportunity to gain deliverance and would have to remain in the round of rebirth until another Buddha appears in the remote future. He could see into the future and thus understood the precious opportunity a Buddha offers, but he could neither postpone his death nor avoid rebirth into the immaterial realm.