Learn English – “Everything is everything”

Google books search shows that "A Disciple", in an article entitled "Emerson's Essays" which appeared in the June 1845 issue of United States magazine and Democratic review, wrote

... as a recent critic on the "Teutonic Metaphysics or American Transcendentalism" has satirically expressed it, "everything is everything, and everything else is everything, and everything is everything else."

I have no idea who this critic was. The expression is simple enough that it might have been coined independently several times, but if this was the original coinage, it cannot have been earlier than American Transcendentalism itself, which puts it 1836 or later.

Note that it's easy for an expression like this to change from a negative to a positive meaning. For instance, "the Big Bang" and "abstract nonsense" were originally expressions meant to slight the Big Bang theory and certain types of argument in mathematics, respectively, but which are now used positively by people in their respective fields.