Manomaya, the Mental Sheath

Manomaya kosha is the third of the five sheaths of Vedantic thought, the sheath made of mind, manas, the faculty of thought, feeling, sensation and the ordinary restless mental activity that processes the input of the senses. It lies within the vital sheath and is subtler still, the layer of instinctive and emotional mind, of likes and dislikes, doubt and imagination.

In the nested scheme of the Taittiriya Upanishad the mental sheath governs the automatic mental life, the stream of thought and reaction, and it is distinguished from the deeper intellectual sheath of discernment that lies within it. The Vedantic analysis treats the mind here as still a covering of the self rather than the self, so that even thought and feeling, closely as we identify with them, are seen as layers to be observed and passed through in the inquiry toward the atman. The five koshas form the classical Indian model of the layered person, and the mental sheath is the middle of the five. The doctrine is ancient and central to Vedanta and yoga.