Taittiriya Upanishad — From Food to Bliss
The Taittiriya Upanishad's Brahmananda Valli (the chapter on Brahman-bliss) is the Upanishads' most systematic exploration of the layers of the Self and the recognition of Brahman as Ananda at the center.
The Taittiriya Upanishad's second chapter (Brahmananda Valli) presents the most systematic Pancha Kosha (five sheath) analysis in all Upanishadic literature, culminating in the recognition of Brahman as Ananda (bliss). It progresses through: the food self (Annamaya — the physical body nourished by food), the vital self (Pranamaya), the mental self (Manomaya), the cognitive self (Vijnanamaya), and the bliss self (Anandamaya). The inquiry at each level: 'Is this the Atman?' Each sheath is shown to be limited, constituted by specific contents, and therefore not the ultimate Self. The Anandamaya (bliss sheath) is the finest and most easily mistaken for the Atman — the joy of deep sleep seems like the goal. But the Taittiriya concludes: even the Anandamaya is a sheath — the Atman is the witness even of bliss. The text then presents the famous calculation of happiness levels, culminating in Brahmananda (the bliss of Brahman) as infinite times greater than the greatest human happiness.
From Ananda (bliss) indeed these beings are born; by Ananda they are sustained; toward Ananda they move and into Ananda they return.
The Taittiriya Upanishad's Brahmananda Valli sets out an ascending 'measure of bliss' (ananda-mimamsa), multiplying one degree of the highest human happiness a hundredfold at each rung — through the joys of celestial beings up to the bliss of Brahman — teaching that every lesser joy is a faint reflection of the Ananda that is Brahman's own nature.
Taittiriya Upanishad