He wrote many other works, mostly theological. His Speculum speculationum ("Mirror of speculations") while not being very original, pulled together a range of topics borrowing from Peter Lombard's Sentences, Augustine, Platonic ideas from William of Conches, Avicenna, Aristotle and others. One of his chief aims in the Speculum was to combat heresy, specifically Catharism's dualism (that good and evil were equal powers). He wrote Fables taken from Æsop and Avianus, and a commentary on Virgil that might have started a legend.
In his commentary, he writes about a poem attributed to Virgil, Culex ("The Gnat"). There is a medieval legend that Virgil (70 - 19BCE; often spelled Vergil in the Middle Ages) had magical powers. What Neckham wrote was Vergilius fecit Culicem ("Virgil made a gnat"). What Neckham is likely to have meant was that Virgil wrote the poem "Gnat," but it was misunderstood to mean that Virgil made a gnat (or fly), and this was taken to mean Virgil had magical powers and could create things.
Shortly after Virgil's death, his home town of Naples started the story that he had founded the city, and/or that he was its governor. Naples also had a story that workmen constructing a temple were plagued by swarms of flies. Virgil's gnat/fly destroyed all the other flies, allowing the men to finish their work in peace.
Virgil's fly gave rise to another legend in the Middle Ages, that he mourned its death and built a lavish tomb for it. The illustration is from Ripley’s Wonder Book of Strange Facts (1957). The Latin inscription reads “Fly, may this urn prove light for you, and may your bones rest easily.” Historians have tried to explain this persistent Virgilian legend as a legal dodge. The government was confiscating estates of the wealthy to be able to give land to returning war heroes (true). The estate could be saved if it held a burial plot (true). Virgil's family had a large estate (true). No contemporary writer, however, mentions any such event in Virgil's life.
A lot of of stories can be spun from the desire to believe amazing things, along with a misunderstood line.
I'd like to return to a mention from yesterday: Neckham's mother was wet nurse to the future King Richard I. What was the life/career of a wet nurse like? We'll look into that tomorrow, and ask the question: is there an appropriate illustration for this topic in a G-rated blog in the United States?