The Chandogya Upanishad is a Hindu scripture. The religious writings that make up the most recent layer of the Vedas include the Brhadaranyaka Upanishad, one of the two oldest upanishads.
Internal textual reasons suggest that the Brhadaranyaka Upanishad is the elder of the two, and since significant parts of both texts are identical, the Chandogya Upanishad is believed to be reliant on it.
Both writings are likewise considerably longer and less structured than the other upanishads, meandering from subject to topic with no clear purpose.
Both are written in prose rather than poetry, and the material is often presented as a conversation between many characters.
Their very speculative debates on the nature of the cosmos were significant sources for subsequent upanishads.
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