Astika (Sanskrit: : "orthodox") and Nastika: ("heterodox") are technical terms in Hinduism used to classify philosophical schools and persons, according to whether they accept the authority of the Vedas as supreme revealed scriptures, or not. By this definition, Nyaya, Vaisheshika, Samkhya, Yoga, Purva Mimamsa and Vedanta are classified as "astika" schools; while Charvaka, Jainism and Buddhism are considered "nastika" schools.