philosophy
What is the antahkarana and what are its four functions in Hindu psychology?
What the tradition says
Antahkarana means "inner instrument" in Sanskrit. The idea comes from Samkhya, Yoga, and Vedanta thought. In this view, just as the eyes and ears are outer instruments that take in the world, the antahkarana is the inner tool that processes it. It is not the true self. It is more like an instrument the self uses. The tradition often splits it into four functions, each with its own job.
The four functions
Manas is the sensory mind. It gathers what the senses bring in and reacts, often without much thought. It is the part that wonders, doubts, and flits from one thing to another. Buddhi is the intellect, the power to decide, judge, and tell one thing from another. Where manas asks "what is this?", buddhi answers "this is so, and I will choose this." Ahamkara is the ego-sense, the feeling of "I" and "mine." It is what makes us claim thoughts and actions as our own. Chitta is memory and the deeper store of impressions, holding what we have lived through, much like a subconscious layer. Some schools count all four; others fold them into fewer parts. The exact split varies between texts.
Where it comes from
These ideas appear across classical Hindu philosophy. Samkhya and Yoga describe the workings of mind and matter, and Vedanta texts return to the antahkarana often. A well-known Vedanta text, the Vivekachudamani, lays out these inner functions while teaching that the real self stands apart from them. Different teachers and schools describe the parts in slightly different ways, so there is no single fixed model.
Why it still matters
People who study meditation and yoga often use this map of the mind today. It gives simple names to inner experience: the restless mind, the deciding intellect, the sense of "I," and the pull of old memories. Many find it a useful way to watch their own thoughts. It is a model of the mind, drawn from philosophy, not a claim from modern brain science, though some find loose parallels with how psychology talks about thinking, judging, ego, and memory.