Buddhi

Buddhi is a Sanskrit term used in Indian philosophy and psychology to denote the intellect or discriminating faculty of the mind. Etymologically, it derives from budh- “to know,” and is commonly translated as intellect, understanding, or reason. In many systems, buddhi is considered one of the inner instruments that compose the antahkarana (the “inner organ”) alongside manas (the mind), ahaṃkāra (ego), and citta (memory or impression).

In classical Samkhya and Yoga philosophy, buddhi is the rational faculty that evolves from mahat (cosmic intellect). It processes sensory data, forms concepts, makes judgments, and guides decision-making. A refined buddhi uses discrimination (viveka) to distinguish the real from the unreal and the permanent from the transient. When purified, it aids right action; when unrestrained, it can contribute to bondage through attachment and misperception.

In Vedanta, especially in Advaita traditions, buddhi is viewed as the instrument through which true knowledge is discerned. It must be illumined by higher consciousness and directed by discernment rather than ego-identification with the body or mind. The cultivation of viveka and detachment helps prevent misidentification of the self with superficial mental states, aiding self-realization.

In other schools such as Nyaya, buddhi is regarded as the instrument of knowledge—one’s capacity for inference, analysis, and rational understanding. In modern usage, buddhi is often equated with intelligence or common sense, but in traditional contexts it specifically refers to the discriminating, insightful aspect of the mind.