The religious literature in this category can be classified into two divisions, heterodox and orthodox. The heterodox schools reject the authority of the Vedas and include Buddhists, Jains, and the Carvakas (materialists). The orthodox schools accept the Vedas and the Vedic literature as authoritative. There are six orthodox schools divided into two groups. The two Mimamsa schools are directly based on the Vedic literature. The Nyaya, Vaiseshika, Sankhya, and Yoga schools are based on slightly different religious ideology, but are consistent with the Vedas. Each Darshana or school has its writings attributed to its founder, including a number of commentaries written later by the followers of these schools.