Kosha

Kosha

"shell", "cover", "case"; shell of the spirit according to Vedanta philosophy.

Various texts, mainly Upanishads, describe five concentric koshas or bodies, (panca = five; kośa = shell, sheath) through which the spirit (Atman) acts on the various layers of being.

Under all these layers is the Atman: pure light, divinity, eternal consciousness, the source of unity. It lies behind the Anandamaya kosha (body of bliss), the most subtle of all shells. But even it is considered an illusion because it is separated from a single source or pure consciousness.

Paingala Upanishad (Shukla Yajurveda) in the second chapter gives a correspondence between five koshas and three bodies (sharira) with the following characteristic:

• Annamaya kosha is the physical body made up of food and developed by the help of food, ultimately absorbed into the earth, which is also a form of food. This is the most gross sheath, sthulasharira (gross body).
• Pranamaya kosha is the pranic body, which is made up of five pranas together with minor ones, as well as karmendriyas.
• Manomaya kosha is a vessel of the mind (manas), which receives impressions from the senses, and, in fact, the senses themselves (jnanendriyas).
• Vijnanamaya kosha represents the body of the intellect – the "body" of wisdom, knowledge, this is the source of buddhi. This sheath is also associated with the jnanendriyas like the previous one. Pranamaya, manomaya and vijnanamaya koshas make up the subtle body – sukshmasharira.
• Anandamaya kosha, the fifth of the sheaths that covers the Atman, is the "body" of ananda and consists of ignorance about its True nature. Anandamaya kosha is associated with the causal body (karanasharira), and it is here, thanks to avidya, that the seeds of karma are formed and preserved, this is the basis of all other grosser bodies and manifestations in this world.

One of the earliest mentions of the five sheaths is found in the Taittiriya Upanishad (second chapter, Brahmananda-valli). It successively describes koshas: annamaya (2nd anuvaka), pranomaya (3), manomaya (4), vijnanamaya (5) and anandamaya (6,7,8,9 anuvakas). At the end of this chapter (in the 8th anuvaka) it is said:

One [Atman] is in this person and in that sun. The one who knows this leaves this world after death and attains the Atman consisting of food, attains the Atman consisting of breath, attains the Atman consisting of thought, attains the Atman consisting of knowledge, attains the Atman consisting of bliss. This is what the scripture says. 

Sarva Upanishad explains the following about the five sheaths:

1. (...) What is annamaya, pranamaya, manomaya, vijnanamaya, anandamaya? What is the actor, soul (jiva), kshetrajna (knowing all the elements), sakshin (realizing), kutastha, inner teacher (antaryamin)? (...)
2. (...) The union of the six sheaths (skin, bones, meat, blood, bone marrow, nerves) built by gross food is annamaya kosha, the food body.
In annamaya kosha 14 winds-pranas (apana, samana, prana, udana, vyana, naga, kurma, krikara, devadatta, dhananjaya, vairambhana, sthanamukhya, pradyota, prakrita) move - this is pranamaya kosha.

When the four subtle consciousnesses (mind, intellect, consciousness and false ego), which are cognizing sound and other subtle objects, are connected to these two bodies, this is called manomaya kosha, the body of the mind. When the observing consciousness above the differentiation appears on top of these three bodies, this is called vijnanamaya kosha, the body of knowledge.
When these four bodies are immersed in Brahman like a tree within a seed, this is called anandamaya kosha, the body of bliss. The one who lives in the body, in the place where the thought of joy and suffering is located, is the one who performs action. 
When thoughts are directed to objects that bring pleasure, it causes joy, when to opposite objects - suffering. The source of joy and suffering is sound, touch, sight, taste and smell. When, according to past good and bad karma, the consciousness gets a connection with past bodies, this is called jiva (soul). 

A body close to the Atman, but still being its subtle limitation, is called linga-sharira. The consciousness that manifests itself in this body is called kshetrajna (who knows all the elements).