The origins of the practice of "dhyana", which culminates into "samadhi", are a matter of dispute. According to Bronkhorst, the mainstream concept is evidenced in Jain, Buddhist and early Hindu scriptures. Dhyana, states Sagarmal Jain, has been essential to Jaina religious practices, but the origins of Dhyana and Yoga in the pre-canonical era (before 6th-century BCE) is unclear, and it likely developed in the Sramanic culture of ancient India, Several "śramaṇa" movements are known to have existed in India before the 6th century BCE (pre-Buddha, pre-Mahavira), and these influenced both the āstika and nāstika traditions of Indian philosophy.