- (Hinduism) A philosophical school or individual accepting certain tenets fundamental to Hinduism, by various definitions:
- The supreme authority of the Vedas.
- The existence of atman (roughly "soul").
- The existence of ishvara (a supreme deity).
The definition of astika is not universally agreed upon. A prime example is Buddhism; many consider it to be nastika since it denies the authority of the Vedas and the Hindu priesthood, while other schools go as far as to consider Gautama Buddha as an avatar of the god Vishnu.