The meta-literary mock legend of St Nemo is the result of one of the more sophisticated linguistic jokes in the medieval period. The Latin indefinite pronoun nemo means ‘no one’ and is found, naturally, in many medieval texts. In the Bible, we are told that ‘no one is accepted as a prophet in his own country’ (nemo propheta acceptus est in patria sua, Luke 4:24) and that ‘no one saw their brother’ (nemo vidit fratrem suum’, Exodus 10:23). In several medieval manuscripts, the text is explained with reference to Nemo, an important figure, a biblical prophet even, enjoying scriptural recognition. The Vulgate Revelation seals St Nemo’s canonicity: ‘And to the angel of the church in Philadelphia write: ‘The words of the holy one, the true one, who has the key of David, who opens and no one [Nemo] will shut, who shuts and no one [Nemo] opens. (Rev 3:7)’. When St Augustine writes ‘For who has seen a black swan? For this reason no one [Nemo] remembers it. Yet who cannot picture it?’ (De Trinitate, XI, 17), it becomes clear that St Nemo is like no one else (pun intended).
In quasi-Ovidian fashion, the indefinite pronoun gets metamorphosed into a fully-fledged, authoritative figure, right in the manuscript gloss. We’re not too far from Captain Nemo and his later incarnations.
In rhetoric, this kind of pun is a subtype of paronomasia or adnominatio, the figure of using words that sound alike but that differ in meaning. It’s something like ‘Knock, knock! Who’s there? No one. No-one who?’. Very funny indeed.
The origin of this pun may not be medieval, however. In the Odyssey, Ulysses tricks the Cyclops into thinking that his name is ‘Nobody’ so that when he and his companion ram the pole into Polyphemus’ eye, the giant’s wailing ‘Come quickly, no one has blinded me!’ makes no sense. The Greek word for ‘no one’ is oὖτις, and works exactly like the Latin ‘nemo’. I do not know to what extent the Ulysses’ clash with the Cyclops was known in the medieval West. For instance, the 13th-century Old Irish retelling of the story in Merugud Uilix maicc Leirtis (The Wanderings of Ulysses son of Laertes) doesn’t include the linguistic cunning.