The narrator says that their friend, a philosopher, taught them about an optical illusion wherein a candle held against a scratched metal surface will make it seem as if the scratches lie in concentric circles around the candlelight (when in fact they are multidirectional). This is a metaphor for how people’s egos (the candle) give the illusion that they are the center of the events that occur around them (the scratches). For example, Rosamond feels that the whole incident of Fred’s illness was actually a way for her and Lydgate to be brought closer together.
The candle anecdote, which is one of many scientific metaphors in the novel, is a powerful way of showing how people’s egos influence their perception of the world. The narrator’s habit of framing social realities using metaphors from science conveys that human social life is not separate from scientific fact, but is rather part of the natural world.
Under Lydgate’s care, Fred gradually gets better, which means that each of Lydgate’s visits gets more pleasant and enjoyable for the family. Whenever Lydgate gets a chance, he sits and listens to Rosamond play music. He feels that their shared flirtation is only a “play at being a little in love,” because he remains convinced that he cannot marry until the New Hospital is finally established. Rosamond, however, believes this is really love and fantasizes of being married. She feels “proud whenever he enter[s] a room” and is sure that he is far superior to all the other suitors she has known.
Rosamond has succumbed to the kind of fantasies that, as we have seen from Dorothea, are potentially dangerous. Rosamond’s dreams have prevented her from seeing that Lydgate is too focused on his career to take the prospect of marriage seriously right now. Furthermore, her fixation on his superiority is shallow. She doesn’t seem to like Lydgate as a person so much as she is infatuated with his rank.
Rosamond doesn’t think about money “except as something necessary which other people would always provide.” Lydgate relishes the time he spends with her, especially because he finds the men of Middlemarch very dull. One evening he finds Rosamond deep in conversation with Ned Plymdale, another young Middlemarch bachelor. Rosamond explains that Lydgate has been the family’s “guardian angel” during Fred’s illness. Lydgate makes several rude, obnoxious comments, leaving Plymdale horrified. Rosamond pretends to be offended, but is secretly thrilled by Lydgate’s pretentious display of superiority. She feels that they are “as good as engaged.”
This passage confirms that Rosamond is in the midst of a misguided illusion when it comes to Lydgate. She embraces his obnoxious behavior and concludes that they are “as good as engaged” despite the fact that they have not even discussed marriage. Furthermore, her naïve understanding of money does not bode well for her future either. It has already been mentioned that Lydgate is poor, but Rosamond is too caught up in fantasy to notice.