Hindu philosophy encompasses the philosophies, world views and teachings of Hinduism that emerged in Ancient India. These include six systems (shad-darśana) – Sankhya, Yoga, Nyaya, Vaisheshika, Mimamsa and Vedanta. In Indian tradition, the word used for philosophy is Darshana. This word comes from the Sanskrit root drish (to see, to experience). Each school of Hindu philosophy has extensive epistemological literature called pramāṇaśāstras, as well as theories on metaphysics, axiology, and other topics.