Reincarnation is the philosophical or religious concept that an aspect of a living being starts a new life in a different physical body or form after each biological death. It is also called rebirth or transmigration, and is a part of the Saṃsāra doctrine of cyclic existence. It is a central tenet of all major Indian religions, namely Buddhism, Hinduism, Jainism, and Sikhism. The idea of reincarnation is found in many ancient cultures, and a belief in rebirth was held by historic figures, such as Pythagoras, Plato, and Socrates. It is also a common belief of various ancient and modern religions such as Spiritism, Theosophy, and Eckankar and is found as well in many tribal societies around the world, in places such as Australia, East Asia, Siberia, and South America.
Although the majority of denominations within the Abrahamic religions of Judaism, Christianity, and Islam do not believe that individuals reincarnate, particular groups within these religions do refer to reincarnation; these groups include the mainstream historical and contemporary followers of Kabbalah, the Cathars, Alawites, the Druze, and the Rosicrucians. The historical relations between these sects and the beliefs about reincarnation that were characteristic of Neoplatonism, Orphism, Hermeticism, Manicheanism, and Gnosticism of the Roman era as well as the Indian religions have been the subject of recent scholarly research.