Buddhist cosmology is central to an understanding of various factors in Southeast Asian culture. Cosmology is a map and a theory about the nature and structure of the universe. In religious descriptions this cosmology can describe various types of rebirth that can achieved through wholesome and unwholesome actions. Buddhist cosmology is then a description of the endless cycle of rebirths known as samsara. In simple terms, if one performs actions harmful to oneself and other, rebirth will be in a realm below that of the human realm. If one performs virtuous actions that benefit oneself and others, rebirth will be achieved in the human realm or one of heavenly realms. In many respects a Buddhist will perform ethical actions, primarily those based upon the five precepts, in order that their rebirth will be auspicious. Ultimately a Buddhist wants to escape from this endless cycle and the achievement of this is what is termed Nibbana. That is the philosophically complicated awakening that it is the ultimate aspiration of a Buddhist to achieve.
Buddhist cosmology contains a number of factors which explains these different types of rebirth. It also elaborates a theory about vast periods of time. Throughout its description the law of kamma is central. It is based upon the idea that all actions, good and bad, have consequences, and that these actions determine the nature of a person’s rebirth. It is an explanation of where and where not to be reborn.
The process of rebirth in Buddhist cosmology is measured in terms of vast aeons of time (kalpa in Sanskrit and kappa in Pali). A kalpa is given the notional figure of 4,320,000 years. The Buddha explained this vast period with a metaphor: Suppose there were a seven mile high mountain made of solid rock. Once a century the top of this mountain is stroked with a piece of silk. The mountain would be worn away before a kalpa has passed. However, more kalpas have passed than there are grains of sand in the banks of the river Ganges (Samyutta-nikaya, II 181-184).
The universe itself, or more correctly the endless cycle of rebirths known as samsara, is divided into three worlds. These worlds are known as dhatu. These three worlds are: The world of the five senses (kama-dhatu); the world of pure form (rupa-dhatu); and the formlessness world (arupa-dhatu).
All of these realms, including the realms of form and formlessness, are in the endless cycle of existences, they are part of samsara and subject to the law of kamma. Although some types of rebirth might contain less suffering than others they are all subject to impermanence and suffering.
Being can be reborn in any one of these three worlds. In the world of the five senses there are eleven levels. In the world of pure form there are sixteen levels and in the formless world there are four levels. This means that spread over the three world are thirty-one possible types of rebirth or planes of existence.
In the world of the five senses the lowest is the hell realm known in Pali as niraya. This comprises a number of very negative rebirths. One such place, described as the great hell, is place where beings are tortured.
Next to the hell realms is the animal realm, the realm of hungry ghosts (petas), and the realm of jealous gods (asuras). Animals are thought to be trapped by desire and instinct. Hungry ghosts or petas, also known as the departed, frequent the human realm due to their attachment to the world. They are sometimes portrayed as having huge stomachs and very thin necks, suggesting their frustration at not being able to satisfy their desires. Jealous gods or asuras are power-seeking and power-hungry beings. Their origins clearly goes back to Indian Vedic mythology.
The realm of human beings is one mixed with suffering and happiness. It is, in many ways, the best type of rebirth as it is from a human rebirth that the escape from rebirth, Nibbana, can be most readily achieved. The most auspicious rebirth is to be born in Jambudipa, the ‘rose apple island’ (a place connected with ideas of ancient India) when a Buddha has been born and is teaching the Dhamma.
Above the human realm are various other possible rebirths. Notable among these is the realm of the thirty-three gods (tavatimsa). This is the place where the Buddha’s mother was reborn after her passing. A mother of a Buddha dies seven days after given birth to her son. There are various reasons given for this, the most common idea is that the womb that has carried a future Buddha cannot again be occupied by a living being. The Buddha, several years after achieving Nibbana ascends to the tavatimsa heaven and teaches the intricate philosophy of Buddhism known as the Abhidhamma. This affords his mother great merit and is in a way symbolic of the Buddha’s respect for his elders. This is celebrated during the Thadingyut festival in October when respect for one’s elders is shown. This is associated with the respect shown by the Buddha to his mother.
In the realm of the contented, the Tusita heaven, dwells the next Buddha, Metteya/Maitreya. He is in meditation, awaiting the appropriate time to descend to his earthly life. This will be when the teachings of the previous Buddha are no longer known. And this will be after a very long period of time. This suggests the fortunate nature of being reborn during the time of a Buddha.
There are sixteen types of rebirth in the realm of pure form. These realms are increasingly subtle, and rebirth in them lasts for increasingly long periods of time. Part of their doctrinal importance is that though being happy destinations and lasting for incredibly long periods of time beings born in them are still subject to the consequences of their actions. The happiness, though long-lasting is impermanent.
The highest part of Buddhist cosmology is reserved for the four formlessness realms (arupa-dhatu) which consists of four types of rebirth: the realm of boundless space, the realm of boundless consciousness, the realm of nothingness and the realm of neither perception nor non-perception. These realms correspond to certain specific states that can be achieved in meditation. Indeed, some scholars of Buddhism have suggested that some aspects of Buddhist cosmology corresponds to states of mind achieved in meditation.
This is the Buddhist model of the endless cycle of existences. It explains how the consequences of actions performed in this life will result in a particular type of rebirth in the future. It also suggests how rebirth in a heavenly realm is subject to the subtle but pervasive suffering of impermanence. Rebirth as an animal or god is comparable in that they are both impermanent and pervaded by dukkha. Buddhist cosmology describes the totality of samsara and ultimately the Buddhist strives to overcome all forms of rebirth either as an animal, a human or a god.