Know the Ātman as the owner of the chariot, and the body as the chariot. Know the buddhi (intellect) as the charioteer, and the mind as the reins.

Here begins the famous chariot metaphor (ratha-kalpa), one of the foundational texts of psychological yoga. The Ātman is the passenger, the physical body is the chariot, the senses are the horses, the objects of the senses are the paths, buddhi (discriminative intellect) is the charioteer, and manas (mind) are the reins. This metaphor illustrates the relationship between the different levels of our being and how they must be coordinated to reach the final destination: realization of the Ātman. It is fundamental for understanding the practice of yoga as integration of all aspects of being.