This interchange of the roles of the two castes is not unique.

In the K[=a]ush[=i]taki Upanishad (4.

19), occurs another instance of a warrior teaching a Brahman.

This, with the familiar illustration of a Gandh[=a]ra (Kandahar) man, the song of the Kurus, and the absence of Brahmanic literature as such in the list of works, cited vii.

1, would indicate that the Ch[=a]ndogya was at least as old as the Br[=a]hmana literature.[18] In their present form several differences remain to be pointed out between the Vedic period and that of the Upanishads.