Hindu's believe that as a person dies the Atman (the unconscious, immaterial part of a human) carries the results of their good and bad actions (Karma) into their next existence. This previous Karma will determine what sort of position a Hindu will inhabit in their new existence, for example: if a person in a low caste has been very good in their past existence, they will be born into a higher caste in their next life. .
The ideas of Karma and Samsara have justified the unequal Caste system, which has been an integral part of Indian society for hundreds of years. At the time of the Rig Veda (the earliest Hindu scriptures around 1000 B.C.E) (Smart 1989: 60) the key concepts of Karma and Samsara had not actually been stated. However, it does mention that a person's conduct in this world determines his life after death. The Brahmins (the religious leaders) stressed the importance of the sacred act of sacrificing which was supposed to have a bearing on man's fate in the next world. Margaret Stutley states that "the Sacrifice becomes the self of the sacrificer in the next world" (Stutley 1985: 23). So, even in this early stage of Hinduism, the idea of Karma played an important role in the Hindu's overview. It was not until the Upanishads (the principal ones dating from 800-400B.C.E) (Smart 1989:49) that we first meet with the doctrines of Karma and Samsara. .
The Upanishads are concerned essentially with the meaning of the sacrificial rites, and come to the conclusion that knowledge in the "true reality" is the key rather than expertise in rituals like the Rig Veda's were. In the process they introduce profound metaphysical and religious ideas, such as Karma and Samsara. The Chandogya Upanishad sums up the ideas of Karma and Samsara "those who are of pleasant conduct here the prospect is indeed that they will enter a pleasant womb, either the womb of a Kshatriya or the womb of a Vaisya (high Indian Castes).
