"Nastika" refers to a category of philosophical schools in Indian thought that do not accept the authority of the Vedas, the ancient sacred texts of Hinduism. This term is often associated with various non-theistic traditions, including Buddhism and Jainism, which offer alternative perspectives on spirituality and ethics. In contrast to astika schools, which affirm the Vedic texts, nastika philosophies emphasize personal experience and rational inquiry. They challenge the notion of a permanent soul and often reject the concept of a creator deity, focusing instead on concepts like karma and liberation from the cycle of rebirth.