The Upanisads are the central scriptures of Hinduism. They represent some of the most important literary products in the history of Indian culture and religion, both because they played a critical role in the development of religious ideas in India and because they are our greatest source for the religious, social, and intellectual history of ancient India. Composed at a time of great social, economic, and religious change, the Upanisads document the transition from the archaic ritualism of the Veda into new religious ideas and institutions.