Vedic period
Some of the earliest surviving Indian philosophical texts are the Upanishads of the later Vedic period (1000–500 BCE), which are considered to preserve the ideas of Brahmanism. Indian philosophy is commonly grouped based on their relationship to the Vedas and the ideas contained in them. Jainism and Buddhism originated at the end of the Vedic period, while the various traditions grouped under Hinduism mostly emerged after the Vedic period as independent traditions. Hindus generally classify Indian philosophical traditions as either orthodox ("āstika") or heterodox ("nāstika") depending on whether they accept the authority of the Vedas and the theories of "brahman" and "ātman" found therein.