Explanation:

Astika derives from the Sanskrit asti, "there is, there exists", and means “one who believes in the existence (of a soul separate from the material world, Brahman, etc.)” and nastika means "an unbeliever". These have been concepts used to classify Indian philosophies by modern scholars, and some Hindu, Buddhist and Jaina texts. Astika has been defined in one of three ways; as those who accept the epistemic authority of the Vedas, as those who accept the existence of atman, or as those who accept the existence of Ishvara. In contrast, nastika are those who deny the respective definitions of astika.