FIVE SHEATHS

The Upanishads speak of the "cave" in which the Atman is hidden. This cave is the five koshas or sheaths surrounding it.  Beginning with the outermost sheath, they are the Annamaya-kosha, the Pranamaya-kosha, the Manomaya-kosha, the Vijnanamaya-kosha, and the Anandamaya-kosha.

The Annamaya-kosha is the gross physical body that is nourished by food. 

The Pranamaya-kosha is the subtle or vital sheath.  It vitalizes and holds together body and mind.  As long as the vital principle exists in the organism, life continues.  The gross manifestation of this sheath is breath.

The Manomaya-kosha is the sheath of the mind, which receives sense impressions.

The Vijnanamaya-kosha is the sheath of intellect. This is the faculty that discriminates, wills.

The Anandamaya-kosha is the sheath of bliss so called, because it is nearest to the blissful Atman.  The bliss sheath normally has its fullest play during deep sleep, when the mind and senses cease functioning.  In light dreaming and wakeful states, it has only a partial manifestation.  This sheath stands all the while between the finite world and the Atman. 

The Atman remains separate from the sheaths and unaffected by their properties.  According to Vedanta the wise man should discriminate between the true self that is the Atman and the koshas, which are non-self.  This discrimination is based upon the fact that the koshas are transient, ever changing.  The Atman is eternal and changeless.