Ātman (/ˈɑːtmən/) is a Sanskrit word that means inner self or soul. In Hindu philosophy, especially in the Vedanta school of Hinduism, Ātman is the first principle, the true self of an individual beyond identification with phenomena, the essence of an individual. In order to attain liberation, a human being must acquire self-knowledge (atma jnana), which is to realize that one's true self (Ātman) is identical with the transcendent self Brahman.
The six orthodox schools of Hinduism believe that there is Ātman (Soul, Self) in every being, a major point of difference with Buddhism, which does not believe that there is either soul or self.
"Ātman" (Atma, आत्मा, आत्मन्) is a Sanskrit word which means "essence, breath, soul." It is related to the PIE *etmen (a root meaning "breath"; cognates: Dutch adem, Old High German atum "breath," Modern German atmen "to breathe" and Atem "respiration, breath", Old English eþian).
Ātman, sometimes spelled without a diacritic as atman in scholarly literature, means "real self" of the individual, "innermost essence", and soul. Atman, in Hinduism, is considered as eternal, imperishable, beyond time, states Roshen Dalal, "not the same as body or mind or consciousness, but is something beyond which permeates all these". Atman is a metaphysical and spiritual concept for the Hindus, often discussed in their scriptures with the concept of Brahman.
The earliest use of word "Ātman" in Indian texts is found in the Rig Veda (RV X.97.11).Yāska, the ancient Indian grammarian, commenting on this Rigvedic verse, accepts the following meanings of Ātman: the pervading principle, the organism in which other elements are united and the ultimate sentient principle.