The Bhagavad Gita (cca. 500 BC) is a philosophical dialogue between the warrior Arjuna and his mythical charioteer Krishna, set on a battlefield symbolizing the inner struggle of human life. It presents a deep psychological model of the self, describing layers of mind—manas (sense-mind), buddhi (intellect), ahamkara (ego), and the true self, atman.
Its Core psychological teaching: freedom arises when one acts without attachment, transcending ego-identification and aligning with the deeper, unchanging Self.