Ancient Indian Literature that comprises of Vedas and other texts focused on how a person becomes rational and how the rationality enables him to take appropriate decisions. Vedas culminate in to Vedanta which have Upanishads embedded within. There are 108 Upanishads available. Spiritual guru, Adi Shankaracharya, studied nearly sixteen of them. Taittriya Upanishad, written by him, explains the philosophy of various kosas/ sheaths covering the soul. The same concept of kosas was explained in his book ‘Atmabodha’ with greater clarity. Panchakosaadi Yogena, Tat Tanmaya Iva Sthitah, Suddhaatma Neelavastraadi, Yogena Sphatiko Yathaa. (When covered with a blue cloth, a pure colourless crystal looks like a blue crystal. Atma with union of five Kosas, appears to have borrowed their qualities upon it). The Five Kosas are: Annamaya, Pranamaya, Manomaya, Vijnanamaya and Ananda Maya.
Shankaracharya, said “the supreme goal of human beings is “self-knowledge”. Just as rice is obtained by pounding paddy and separating the husk, bran etc., pure Atma gets separated from the five Kosas that have encircled it through careful discrimination. This detachment makes individual realize knowledge of the self and makes him rational to think and act effectively in decision making. The concept has been discussed in the paper.