the existence of an afterlife in another world and in reincarnation, The Buddha also asserted that karma influences rebirth, and that the cycles of repeated births and deaths are endless. Before the birth of Buddha, ancient Indian scholars had developed competing theories of afterlife, including the materialistic school such as Charvaka, which posited that death is the end, there is no afterlife, no soul, no rebirth, no karma, and they described death to be a state where a living being is completely annihilated, dissolved. Buddha rejected this theory, adopted the alternate existing theories on rebirth, criticizing the materialistic schools that denied rebirth and karma, states Damien Keown. Such beliefs are inappropriate and dangerous, stated Buddha, because such annihilationism views encourage moral irresponsibility and material hedonism; he tied moral responsibility to rebirth. The Buddha introduced the concept that there is no permanent self (soul), and this central concept in Buddhism is called anattā. Major contemporary Buddhist traditions such as Theravada, Mahayana and Vajrayana traditions accept the teachings of Buddha. These teachings assert there is rebirth, there is no permanent self and no irreducible ātman (soul) moving from life to another and tying these lives together, there is impermanence, that all compounded things such as living beings are aggregates dissolve at death, but every being reincarnates. The rebirth cycles continue endlessly, states Buddhism, and it is a source of duhkha (suffering, pain), but this reincarnation and duhkha cycle can be stopped through nirvana. The anattā doctrine of Buddhism is a contrast to Hinduism, the latter asserting that "soul exists, it is involved in rebirth, and it is through this soul that everything is connected." Different traditions within Buddhism have offered different theories on what reincarnates and how reincarnation happens. One theory suggests that it occurs through consciousness (Sanskrit: vijñāna; Pali: samvattanika-viññana) or stream of consciousness (Sanskrit: citta-santāna, vijñāna-srotām, or vijñāna-santāna; Pali: viññana-sotam) upon death, which reincarnates into a new aggregation. This process, states this theory, is similar to the flame of a dying candle lighting up another. The consciousness in the newly born being is neither identical to nor entirely different from that in the deceased but the two form a causal continuum or stream in this Buddhist theory. Transmigration is influenced by a being's past karma (Pali: kamma). The root cause of rebirth, states Buddhism, is the abiding of consciousness in ignorance (Sanskrit: avidya; Pali: avijja) about the nature of reality,