Although the doctrine of karma is central to all Indian religions, it is difficult to say when and where in India the concept of karma originated. In Jainism, it is assumed its development took place in an era from which the literary documents are not available, since the basics of this doctrine were present and concluded even in the earliest documents of Jains. "Acaranga Sutra" and "Sutrakritanga", contain a general outline of the doctrines of karma and reincarnation. The roots of this doctrine in Jainism might be in the teachings of Parsva, who is said to have lived about two hundred fifty years before Mahavira. The Jain conception of karma—as something material that encumbers the soul—has an archaic nature which justifies the hypothesis that it goes back to 8th or 9th century BCE.