If you want to go further back, the ‘featherless bipeds’ quip is a reference to Diogenes of Sinope making fun of Plato by walking into the academy with a plucke

If you want to go further back, the ‘featherless bipeds’ quip is a reference to Diogenes of Sinope making fun of Plato by walking into the academy with a plucked chicken shouting “Behold Plato’s man!” All literature is a conversation between books, and all philosophy is a footnote to plato.