samsāra ［輪廻］ (, Pali; rinne): Transmigration. The cycle of birth and death that ordinary people undergo in the world of illusion and suffering. In India, the theory of transmigration first appeared in Upanishad philosophy, before the rise of Buddhism, in the eighth or seventh century b.c.e. Buddhism holds that ordinary people undergo an endless cycle of birth and death within the threefold world (the worlds of desire, form, and formlessness) and among the six paths (the realms of hell, hungry spirits, animals, asuras, human beings, and heavenly beings). This repeated cycle of birth and death in the realms of illusion and suffering is referred to as “transmigration in the six paths.” Unenlightened beings are born into one of the six paths in accordance with their actions in their previous existence; when the present life is over, they are reborn in the same or another of the six paths, repeating this process so long as they fail to free themselves from it.
The Buddhist concept of emancipation ( vimoksha) means liberation from this repeated cycle of birth and death in the realms of illusion and suffering. Freeing oneself from transmigration in the six paths was considered the goal of Buddhist practice. The causes for such transmigration were regarded as ignorance of the true nature of life and selfish craving. Liberation from them required awakening to the truth and eliminating selfish craving, and was considered to lead to the attainment of nirvana, or emancipation.