The gross body is made up of food. The mind, the intellect, the chitta and the Ahamkara constitute the subtle body. It is the subtle body that experiences pain and pleasure. The illumination mind comprises the causal body. It transcends worldly thoughts and feelings. There is no trace of desire, anger, greed, ego, pride and jealousy in it. The level of illumination mind is reached only when all the worldly thoughts are subdued.
(From : Sai Veda, The Word of God, sayings of Bhagawan Sri Sathya Sai Baba)