In the 26th chapter, the Primrose family has a long conversation with Ephraim Jenkinson over dinner. As they speak, Jenkinson reflects on his younger years and what he has learned from his life as a con artist. Jenkinson uses paradox to express his view on the value of knowledge: "Indeed I think from my own experience, that the knowing one is the silliest fellow under the sun."
What makes this sentence paradoxical is that "knowing" and "silly" are opposites in meaning. At first, this might seem like an odd statement to make. However, the paradox becomes more meaningful as Jenkinson explains that his childhood intelligence is what pushed him into a dishonest life of deception and scams. Because he was seen as so cunning, no one dared trust him. While honest men like the rather simple Flamborough grew rich, the cunning Jenkinson made minimal money in dishonest ways. He explains that his intelligence kept him from wealth and stability, "without the consolation of being honest."
Jenkinson has come to see that honesty and humility bring much more to life than intelligence and tricks. Although he seems to feel that he is past the point of redemption, the chapter ends with Jenkinson running off to help Dr. Primrose and his family. This suggests that he is ready to make amends and seek redemption for his multiple scams of the Primroses.
In the 20th chapter, George recounts going to Holland to work as an English teacher for Dutch people. At this moment in the story, he brings up a paradox of language instruction and language learning:
It was not till this very moment I recollected, that in order to teach Dutchmen English, it was necessary that they should first teach me Dutch. How I came to overlook so obvious an objection, is to me amazing; but certain it is I overlooked it.
Before his journey to Holland, it does not occur to George that it might be challenging for him to teach his language to people whose language he doesn't himself know. As a result, he cannot do the job he set out to do. In addition to producing a comical situation, George's language-learning conundrum brings up a curious dilemma akin to that of the chicken or the egg. If the Dutch people need George to know their language before he can teach them English, who will he learn Dutch from?
Of course, this isn't an absolutely unsolvable paradox. Even in Goldsmith's time, there would have been people in Holland who already spoke English as well as plenty of people in England who speak Dutch. Nevertheless, the paradoxical situation that prevents George from doing his job provides a moment of levity in his long story of letdowns.