12.4 Intellectual Sheath (Vijnyaanamaya Kosha) and Intellectual Purusha (Vijnyaanamaya Purusha)

Intellectual Sheath : Inside the mental sheath, and pervading it, there is another body which is the self of the mental sheath. The organs of knowledge and the intellect are its components (Vivekachoodaamani 186). It is called the intellectual sheath. The pervasive awareness that understands this sheath as its "I-me" is called the intellectual Purusha.
 
"Verily, different from this [sheath], which consists of the essence of the mind, but within it, is another self, which consists of intellect (vijnyaana). By this the former is filled. This too has the shape of a man. Like the human shape of the former is the human shape of the latter. Faith (shraddhaa) is its head, what is right is its right wing, what is truth is its left wing, absorption (yoga) is its trunk, Mahat (Hiranyagarbha) is its tail, its support." (Taittireeya Upanishad 2.4.1). This means that the science (vijnyaana) of worldly and Vedic actions, the conviction of the real nature of worldly and Vedic facts, the resolutions of all doubts pertaining to those facts, and the casting out of all unnecessary arguments - this is the intellectual sheath. In this, the thought-flow-endowed intellect along with the organs of knowledge remains. The arrogation (abhimaana) of doership also stays in this sheath. The cause of the microcosmic (vyashti) intellect is the Mahat element. That is why the support of the intellectual sheath is the Mahat element alone.
 
"I am the knower, the doer, of so-and-so caste, of so-and-so life stage, I am the body or the individual soul distinct/disconnected from the body, I am a sinner, a saint" etc. - whichever arrogations of action, enjoyment or sensory knowledge exist, all those are transformations (vikaaraas) of the intellectual sheath, since it pervades the afore-mentioned three sheaths.
 
This intellectual Purusha is an individual soul with the nature of "I" (aham svabhaava vaalaa). He is the one who accomplishes all worldly and other-worldly transactions. He acts due to past desires (vaasanaas) and enjoys their results, and falls into the trap of arrival and departure. Waking and all other states, joy-sorrow and other enjoyments (bhoga), arrogations of body etc. and the sense of mine (mamataa) reside in this sheath (Vivekachoodaamani 188-190).
 
By being the saatvic modification of the Mahat element, this intellectual sheath is extremely knowledge-filled but is not the knowledge-nature self. Due to delusion, this intellectual sheath alone has been accepted in the form of the self. In reality, it is an adjunct with extreme proximity to the knowledge-nature self, which causes the afore-mentioned delusion. The entire set of transactions of the intellectual sheath is a scene, it is change-oriented. In deep sleep, when the intellect sleeps, this sheath is not available. Therefore it cannot be the "I", the self.