This episode is about written language, as the Greek philosopher Plato describes it in his dialogue Phaedrus.

The Latin proverb I cite is Verba volant, scripta manent; and the Greek word that means both 'cure' and 'poison' is pharmakon.

The quotation from John Milton is from Areopagitica (1644).

Selections from Plato’s Phaedrus are from Benjamin Jowett’s 1892 translation, as cited in the anthology Critical Theory Since Plato, 3rd edition of 2005, edited by Hazard Adams and Leroy Searle.