Write a note on the central theme of Chandogyopanisad.

The central theme of the Chandogya Upanishad, one of the principal Upanishads in the Vedic tradition, revolves around the exploration of the nature of reality, the self (Atman), and the ultimate reality (Brahman). Composed in the form of a dialogue between the sage Uddalaka Aruni and his son Shvetaketu, the Upanishad delves into profound metaphysical and philosophical inquiries.

A key focus of the Chandogya Upanishad is the teaching of "Tat Tvam Asi," meaning "That Thou Art." This phrase encapsulates the essential unity between the individual self (Atman) and the ultimate reality (Brahman). The Upanishad employs various allegories, analogies, and meditative practices to elucidate the interconnectedness of the individual soul with the universal essence.

Through stories, discourses, and contemplative exercises, the Chandogya Upanishad guides the seeker to recognize the underlying oneness of all existence. It emphasizes the importance of self-realization, highlighting that the true nature of the self is identical to the ultimate reality, and realizing this unity leads to liberation (moksha) from the cycle of birth and death (samsara). The Upanishad's central theme of realizing the profound identity of the individual self with the transcendent reality contributes significantly to the philosophical foundation of Vedanta.