In Buddhism, the term anattā or anātman is the doctrine of "non-self" – that no unchanging, permanent self or essence can be found in any phenomenon. While often interpreted as a doctrine denying the existence of a self, anatman is more accurately described as a strategy to attain non-attachment by recognizing everything as impermanent, while staying silent on the ultimate existence of an unchanging essence. In contrast, dominant schools of Hinduism assert the existence of Ātman as pure awareness or witness-consciousness, "reify[ing] consciousness as an eternal self."

Ātman is a Sanskrit word for the true or eternal Self or the self-existent essence or impersonal witness-consciousness within each individual. Atman is conceptually different from Jīvātman, which persists across multiple bodies and lifetimes. Some schools of Indian philosophy regard the Ātman as distinct from the material or mortal ego (Ahamkara), the emotional aspect of the mind (Citta), and existence in an embodied form (Prakṛti). The term is often translated as soul, but is better translated as "Self", as it solely refers to pure consciousness or witness-consciousness, beyond identification with phenomena. In order to attain moksha (liberation), a human being must acquire self-knowledge.