Ātman

Ātman is the Sanskrit word for the self. In ordinary use it is simply a reflexive pronoun, “oneself”; in the Upaniṣads it becomes the name of what a person most truly is, beneath body, senses and mind. The Bṛhadāraṇyaka Upaniṣad calls it the inner controller and the unseen seer, and the Chāndogya identifies it with the subtle essence of all things in the teaching “that thou art”.

The Upaniṣads approach the self by subtraction. One by one, body, breath, mind and the intellect are shown to be things the self has or uses, not the self itself. What remains is the witness: awareness that can never become an object for itself. The Kaṭha Upaniṣad pictures it as the rider in a chariot, with the senses as horses and the mind as reins.

The schools of Vedānta agree that the self is conscious, eternal and distinct from the body. They disagree about whether there is one self or many, and about its relation to Brahman. Buddhism, by contrast, teaches anātman, “non-self”: no permanent self can be found among the constituents of a person, and the belief in one is a root of suffering.