"The word moot cosyn be to the werkyng"

Whereas in the Canon's Yeoman's Tale, with alchemy, we got a metaphor for authorship, in the Manciple's Tale, we get a blunt argument about language, meaning and the relationship between the two. 

The Manciple begins his argument by digressing from his story just as he is relating the wife's affair with her "lemman," or lover. He begs the other pilgrims to forgive him his "knavyssh speche" — his error in applying a churlish term to a gentlewoman, or lady, and not a commoner (205). He pursues this digression by explaining the theory that words must match their meaning, action or subject. Referencing Plato, he says, "The word moot nede accorde with the dede. / If men shal telle proprely a thyng, / The word moot cosyn be to the werkyng" (208-210) Basically, "lemman" belongs to the sphere of fornication among commoners, not to the sphere of love among nobility — he should have used a word that carried with it implications of nobility and "gentilesse." 

The phrase that the word must be cousin to the working, or deed, was actually coined by Boethius, through whom Plato's arguments in the Cratylus "came down to the Middle Ages" (Cooper 60). The question of the relationship between language and meaning is one that has been debated by philosophers for centuries, and Helen Cooper briefly touches on this debate in her review of John Fyler's work, Language and the Declining World in Chaucer, Dante, and Jean de Meun. She writes that Aristotle disagreed with Plato, "arguing in On Interpretation that names are bestowed ad placitum, at the whim of the individual language, effectively at random" (60). 

Chaucer would seem to agree with Aristotle that words are assigned arbitrarily. Through the manciple, he undercuts Plato's argument about language by baldly saying that, whether noble or common, cheating is cheating and differences in words can't conceal that common element:

"Ther nys no difference, trewly,

Bitwixe a wyf that is of heigh degree,

If of hir body dishonest she bee,

And a povre wenche, oother than this—

If it so be they werke bothe amys."

(l. 212-216)

The manciple then proceeds to discuss the arbitrary application of specific terms according to class and status. A noblewoman has a lover, and is still called a lady, but a poor woman is called a wench or lemman. Fundamentally, the manciple says, men lie the one as low as the other, and sex is all the same, whatever the appellation (222). He continues this argument about arbitrariness in lines 223 through 234, but steps back by claiming that he's not a learned man: "I am a man nought textueel / I wol nought telle of textes never a deel" (235-236). Here, we again see Chaucer forcing his characters to falsely testify their ignorance and causing us, as readers, to realize that the manciple, among other characters who've recanted, are themselves arbitrary creations through which Chaucer the narrator/author is speaking. 

Chaucer creates a metaphor for this falseness when Phebus accuses the crow of lying and strips him of his ability to speak. Ironically, we are now aware that words don't accord with the actions they refer to, and that the sign can be divorced from the thing. This principle allows the manciple/Chaucer to create a scene in which Phebus calls the truth a lie, a scene the manciple follows up with a warning to "taketh kep what that ye seye" because once spoken, words escape the speaker's control and can be manipulated and re-labeled. 

Perhaps Chaucer, near the end of his Tales, is cognizant of the fact that once he completes his written work and releases it upon the world, "he may by no wey clepe his word agayn. / Thyng that is seyd is seyd, and forth it gooth" (354-355). Thus, the copious amount of denials and retractions he writes into his characters' tales — either he is covering his bases, or he is playing with the reader, pointing to the malleability and arbitrariness of language. Funnily enough, he refuses to listen to the manciple's advice to "be noon auctor newe / Of tidynges, wheither they been false or trewe ... Kepe wel thy tonge and thenk upon the crowe" (359-360, 362). Like the crow, Chaucer tells his reader all the flaws and foibles of medieval English society. But unlike the crow, he seems to have avoided punishment for his "wikked tongue." 

Cooper, Helen. "Untitled review." Essays in Criticism. LIX:1, January 2009. 59-65.