Tibetan mandala Kalachakra cosmogony (buddismnews.blogspot.com)
The Buddhist universe consists of thirty-one planes of existence (see chart). Every being lives on one or another of these planes. After death all beings, except arahants, will be reborn in a realm and under circumstances that accords with their karma — their volitional actions of body, speech, and mind willed and accumulated in that or any previous existence.
The lowest area (Planes 1-11) is called the Sensuous Sphere; sense experience predominates. Next comes the Fine-material Sphere (12-27) attained by practicing the fine-material absorptions (rupa-jhanas). Above that is the Immaterial Sphere (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 this plane. Why? The human world provides the best opportunity to practice the Dharma and attain liberation: On the lower four planes, little progress can be made because 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 Round of Rebirth that is essential to liberation.
